Kratom use among ethnobotanical tea bar patrons in Colorado: Subjective drug effects, adverse reactions, and perceived benefits of use

Abstract

Introduction

Kratom use is increasing in the US, yet data characterizing use patterns, risks, and benefits is limited. Additionally, there are few data on the acute subjective effects of kratom in humans, and no studies to-date have examined kratom use within US public consumption settings, which have become increasingly popular in recent years.

Methods

Using field methods, we administered surveys to 102 ethnobotanical tea bar patrons in northern Colorado. Surveys assessed demographic information, kratom use patterns, perceived benefits, and adverse reactions. We also assessed subjective drug effects acutely after participants consumed kratom at the bars. Data were analyzed using a mixed-methods approach.

Results

Participants (mean age=22.34 years, 39.2 % women), reported frequent kratom use (73.4 % endorsed weekly use, 19.3 % endorsed daily use). Reported benefits included mental and physical health benefits, social enhancement, and substance use harm reduction. Adverse reactions primarily involved gastrointestinal issues, though acute psychological effects (e.g., anxiety), and withdrawal symptoms were also cited. Kratom use in a bar setting was associated with acute stimulation and mild euphoria, and minimal sedation.

Conclusions

While most participants reported perceived benefits, the presence of adverse reactions highlight the need for more data on safety and risks of kratom use, particularly within public consumption spaces. Results also highlight the possible role of kratom in supporting substance use disorder recovery, with some ethnobotanical tea bars potentially functioning as recovery spaces.

Graphical Abstract

Highlights

• •Kratom use in a bar setting produces acute stimulation, mild euphoria, and minimal sedation.
• •Perceived benefits and adverse reactions to kratom are diverse.
• •Ethnobotanical tea bar patrons include individuals in addiction recovery.

1. Introduction

1.1. Kratom use in the United States

Mitragyna speciosa (i.e., kratom) is a psychoactive plant indigenous to Southeast Asia that has increased in popularity across the US in recent years (Grundmann, 2017, Prozialeck et al., 2012). Evidence from the National Survey on Drug Use and Health suggests that nearly 2 million Americans reported kratom use in 2022 (Substance abuse and mental health services administration., 2023), yet industry reports place estimates between 5 and 15 million US adults (American Kratom Association, 2019). Marketed as a dietary supplement, rising rates of kratom use may be attributable to the botanical’s various purported effects, with motivations for use that include increased focus, nonmedical self-management of physical pain and psychiatric symptoms (e.g., anxiety), and use of kratom to self-manage substance use disorders (SUDs) (Grundmann et al., 2022, Smith et al., 2024a, Smith et al., 2022b, Smith et al., 2021b, Smith and Lawson, 2017). Notably, however, there have also been some reports of toxicity and overdose fatalities involving kratom exposure, typically involving complicated health history and polydrug use (Corkery et al., 2019, Eggleston et al., 2019, Olsen et al., 2019). Development of kratom physical dependence (e.g., tolerance, withdrawal) and DSM-5-derived SUD for kratom (i.e., kratom use disorder; [KUD]) have also been documented among some people who use kratom regularly (Hill et al., 2024, Smith et al., 2022a, Weiss et al., 2024).

Currently, kratom is unscheduled at the federal level and legal in most US states, with some states adopting legislation to regulate kratom (Ellis et al., 2023). Despite kratom’s lack of federal regulation, proliferating product formulations, and increasing popularity, human data on kratom remains limited in comparison to other commonly used substances. Current scientific gaps, while narrowing, hinder individuals' ability to make informed decisions about their use, while leaving policy makers and clinicians without the data necessary to develop appropriate regulations and health recommendations.

1.2. Kratom use at ethnobotanical tea bars

One area of kratom consumption in the US that is rapidly changing are public settings in which kratom preparations are served. Based on an informal search conducted in the spring of 2024, we estimate that there are approximately 28 states with ethnobotanical tea bars that serve kratom products, totaling over 300 bars. These establishments offer communal settings for the consumption of prepared kratom beverages, often alongside other botanical beverages, such as those prepared from Piper methysticum (kava)— a psychotropic plant indigenous to the Pacific Islands that is commonly consumed by people who use kratom (Pont-Fernandez et al., 2023). For researchers, tea bars provide a unique opportunity to study kratom consumption in a real-world context, providing ecological validity that retrospective surveys lack (Coe et al., 2019, Hill et al., 2024, Smith et al., 2022b, Smith et al., 2022c, Smith et al., 2022a, Smith et al., 2021a, Smith and Lawson, 2017). At the time of this writing, there are no published data on ethnobotanical tea bar patrons in the US, raising several significant public health concerns and opportunities for exploration of use patterns heretofore unexamined.

With respect to public health, few data exist on kratom’s impairing effects, yet tea bar patrons may drive following consumption (Kerrigan and Basiliere, 2022, Wright, 2018, Zamarripa et al., 2024). Moreover, patrons may consume multiple kratom beverages while visiting tea bar spaces, potentially elevating impairment and driving-related risks. Drinking at a bar or club (compared to drinking at home) has been identified as a significant risk factor for driving after binge drinking in the alcohol literature (Naimi et al., 2009), but it is currently unknown whether this is true for kratom. The social environment at tea bars may also exacerbate these risks, as evidence suggests that social drinking locations, such as bars, can promote and facilitate heavier consumption patterns (Kypri et al., 2010). Additionally, given the pleasant effects of kratom, which do not appear to result in high ratings of euphoria (Smith et al., 2024b, Smith et al., 2024c), many people report using regularly (e.g., daily) to improve quality-of-life and to support recovery from SUDs (Smith et al., 2022b). However, it is unknown whether bar patrons are primarily individuals in SUD recovery with more substantive substance use history, or individuals who use substances more 'casually' without SUD history. While people who use kratom regularly have shown minimal impairment from kratom (Smith et al., 2024c, Zamarripa et al., 2024), individuals who consume kratom regularly (with or without SUD history) may differ from individuals who are kratom naïve or consume kratom infrequently. For example, evidence from the cannabis literature suggests that people who consume cannabis regularly exhibit reduced sensitivity to the neurocognitive effects of Δ9-tetrahydrocannabinol (D’Souza et al., 2008, Hart et al., 2001, Ramaekers et al., 2009).

1.3. Current study

We aimed to characterize kratom use patterns among a sample of ethnobotanical tea bar patrons in northern Colorado and to assess subjective drug effects associated with kratom use in these settings. As this is a novel area of research, we also qualitatively evaluated bar patrons’ perceived benefits of using kratom and prior experience of adverse reactions to kratom. Given the absence of data on kratom use in ethnobotanical tea bars, aims are considered exploratory and no a priori hypotheses were made.

2. Methods

2.1. Participants

Data were collected from 102 ethnobotanical tea bar patrons (Table 1) across two tea bars in northern Colorado between fall 2023 and spring 2024. Individuals aged 18 or older were eligible for participation, as data were collected prior to the implementation of legislation in Colorado restricting kratom consumption to individuals aged 21 or older (effective July 1, 2024).

Table 1.

Respondent characteristics.

Characteristics	N	%	M	SD	Min	Max
Age			22.34	5.45	18	51
Gender
Gender fluid	3	3.1
Gender queer	1	1.0
Man	53	54.6
Woman	38	39.2
Non-binary	2	2.1
Transgender
Yes	3	3.1
No	92	94.8
Prefer not to answer	2	2.1
Ethnicity
Arab, Middle Eastern, or North African	8	8.2
Asian or Asian American	10	10.2
Black or African American	5	5.1
Hispanic or Latino	19	19.4
Native American or Alaska Native	1	1.0
Native Hawaiian or Other Pacific Islander	2	2.0
White or European American	73	74.5
Not listed	5	5.1
Prefer not to answer	2	2.0
Race
Asian	5	5.1
Black	2	2.0
Indigenous, Aboriginal, or First Nations	1	1.0
Latino or Hispanic	12	12.2
Middle Eastern	0	0.0
White	85	86.7
Not listed	0	0.0
Prefer not to answer	1	1.0
Sexual Orientation
Straight or heterosexual	68	69.4
Lesbian	6	6.1
Gay	2	2.0
Bisexual	12	12.2
Pansexual	5	5.1
Sexually fluid	2	2.0
Queer	4	4.1
Demisexual	1	1.0
Asexual	1	1.0
Aromantic	0	0.0
Questioning	1	1.0
I use a different term	0	0.0
Prefer not to answer	0	0.0
Education
Less than high school	5	5.1
High school diploma or GED	27	27.6
Some college	45	45.9
Associates degree or technical certification	10	10.2
Bachelor’s degree	8	8.2
Master’s degree	3	3.1
Doctoral degree	0	0.0
Household Income
$0-$9,999/yr	24	24.5
$10,000-$19,999/yr	9	9.2
$20,000-$29,999/yr	7	7.1
$30,000-$39,999/yr	15	15.3
$40,000–49,999/yr	8	8.2
$50,000-$59999/yr	7	7.1
Over $60,000/yr	18	18.4
Prefer not to answer	10	10.2

Note. Gender in this table refers to the socially constructed roles, behaviors, and identities of women, men, and gender-diverse individuals, shaped by historical and cultural contexts, and varying across societies and over time. M, mean. SD, standard deviation

2.2. Procedure

Bar patrons were recruited to complete two surveys using street-intercept methods. Specifically, participants were recruited to participate in the first survey 1) as they entered the bar or 2) if they were already present at the bar upon the arrival of study staff. All participants who completed the first survey were given the opportunity to complete a second survey before leaving. Compensation was $10 for survey 1 and $5 for survey 2. This study was approved by the Institutional Review Board at Colorado State University on June 12th, 2023 (protocol #4543). All procedures were performed in accordance with relevant laws and institutional guidelines, and all participants consented to participate.

2.3. Measures

2.3.1. Survey 1

2.3.1.1. Kratom use patterns

Participants were asked to report how frequently they consume kratom and how often they visit ethnobotanical tea bars. They were also asked to report on their use of other substances, age of first kratom use, how long they have been using kratom regularly, and kratom products (e.g., tea, extract) and serving sizes typically consumed. SUD history was also assessed, including prior diagnosis by a healthcare provider and self-diagnosis. Finally, they were asked about current kratom use to reduce other substance use.

2.3.1.2. Perceived benefits of kratom

Participants were asked to write a qualitative text response to the open-ended question: “What are some of the benefits you experience from kratom?”

2.3.1.3. Adverse reactions to kratom

Participants were asked “Within a single session of use (e.g., a night out), have you ever experienced any negative or unwanted effects while consuming kratom?” If participants selected “yes,” a text-response box was provided for qualitative entries.

2.3.2. Survey 2

2.3.2.1. Subjective drug effects

Subjective drug effects were measured via the Amphetamine, Morphine-Benzedrine, and Pentobarbital-Chlorpromazine-Alcohol subscales of the Addiction Research Center Inventory (ARCI) (Kirk and De Wit, 2000), the Biphasic Alcohol Effects Scale (BAES) (Martin et al., 1993) adapted for kratom, and the Drug Effects Questionnaire (DEQ) (Morean et al., 2013). The DEQ is used to help identify the addiction potential indicators of a substance (Comer et al., 2012). For instance, higher ratings for "liking" and feeling "high" are associated with greater addiction liability.

2.3.2.2. Total drinks consumed

To assess total botanical drinks consumed, participants were provided with a menu of the drinks served at each bar and were instructed to enter the total number of drinks they consumed for each product listed.

2.4. Analysis

Four participants who reported having never used kratom were excluded from analysis, leaving a sample size of N = 98 for survey 1. A subset of participants (N = 57) completed survey 2 as they exited the bar. Of those participants, seven reported only consuming kava during their bar visit, leaving N = 50 participants who reported on subjective effects of kratom. Descriptive statistics used to characterize the sample and subjective effects of kratom were computed in IBM SPSS Statistics for Windows version 29. When participants provided a range for total number of drinks consumed, the average was calculated and reported. Qualitative data on perceived kratom benefits and prior adverse reactions to kratom was analyzed thematically (Braun and Clarke, 2006) in Microsoft Excel for Microsoft 365 MSO Version 2409. Authors CJP and JB independently reviewed participants’ responses to familiarize themselves with the data and generate initial codes. They then met to collaboratively discuss and refine codes, creating a final codebook which included code definitions and exemplars. Next, CJP and JB independently coded all text data, meeting again to resolve coding discrepancies until 100 % agreement was reached. CJP and HCK then met to identify, define, and name themes, which were subsequently reviewed and agreed upon by JB.

3. Results

3.1. Sample characterization

3.1.1. Participant demographics

Participants (Table 1) ranged from 18 to 51 years old (mean=22.34, SD=5.45) and were comprised of predominantly men (54.6 %) and women (39.2 %), most of whom identified as cisgender. Most participants identified as White or European American (74.5 %) and straight or heterosexual (69.4 %).

3.1.2. Kratom use patterns

As shown in Table 2, most participants reported using kratom (any kind) frequently (73.4 % endorsed weekly use and 19.3 % endorsed daily use) and visiting tea bars regularly (80.6 % reported visiting tea bars at least once per week and 12.2 % reported visiting tea bars daily). For approximately one third of the sample (33.7 %), length of using kratom at this frequency was 1–2 years. Over half (56.1 %) reported using kratom at their current frequency for 1 year or less. Mean age of first use was 20.46 (SD=5.40), with 16.4 % reporting first use before the age of 18. The most common method of kratom consumption reported by participants was prepared tea from a bar or store (74.5 %) or self-prepared tea (29.6 %), which was approximately the same rate as pre-made concentrated/liquid extract kratom products (24.5 %). Kratom was purchased most commonly from bars (87.8 %).

Table 2.

Kratom use patterns and substance use history.

Survey Item	M	SD	N	%
Age of first kratom use	20.46	5.40
Frequency of Kratom Use
I've tried kratom, but no longer use it			9	9.2
Once every 3–6 months (2–4 times/year)			2	2.0
Once every 2 months (6 times/year)			2	2.0
Once a month (12 times/year)			3	3.1
2–3 times a month			10	10.2
Once a week			5	5.1
Twice a week			10	10.2
3–4 times a week			28	28.6
5–6 times a week			10	10.2
Once a day			12	12.2
More than once a day			7	7.1
Duration of Using Kratom at Reported Frequency
Less than 1 month			4	4.5
1–3 months			14	15.7
3–6 months			14	15.7
6–9 months			9	10.1
9–12 months			9	10.1
1–2 years			30	33.7
2–3 years			9	10.1
Frequency of Visiting Tea Bars
Never, this is my first visit			2	2.0
Once every 2 months (6 times/year)			3	3.1
Once a month (12 times/year)			4	4.1
2–3 times a month			10	10.2
Once a week			9	9.2
Twice a week			10	10.2
3–4 times a week			27	27.6
5–6 times a week			21	21.4
Once a day			11	11.2
More than once a day			1	1.0
Methods of Kratom Consumption
Self-prepared kratom tea			29	29.6
Kratom tea purchased from a store or bar			73	74.5
As a concentrate/liquid extract (e.g., shot)			24	24.5
Smoking or vaporizing			1	1.0
Powdered kratom (pure or in a pill)			9	9.2
Powdered kratom consumed with food			1	1.0
Powdered kratom consumed with other beverage			6	6.1
Other			1	1.0
Sourcing of Kratom Products
Bar			86	87.8
Smoke shop			12	12.2
Gas station			2	2.0
Kratom wholesale store			11	11.2
Online			2	2.0
Diagnosed with Substance Use Disorder
Yes			11	11.3
No			83	85.6
I don't know			3	3.1
Perceived Substance Use Disorder
Never			47	48.5
A long time ago, but not now			22	22.7
Recently, but not now			18	18.6
Currently			10	10.3
Currently Using Kratom or Kava to Reduce Use of Another Drug
Yes			39	40.2
No			58	59.8
Past Year Use of Other Substances
I've never used any of these substances			7	7.1
Tobacco/nicotine products			73	74.5
Alcohol			76	77.6
Cannabis			72	73.5
Synthetic cannabis (Serenity, Spice, K2)			2	2.0
MDMA / Ecstasy / Molly			14	14.3
LSD			13	13.3
Powder cocaine			14	14.3
Crack/rock/freebase cocaine			1	1.0
Psilocybin / Magic mushrooms			33	33.7
DMT			4	4.1
Ketamine			13	13.3
Nitrous Oxide "Whip-its"			11	11.2
Poppers			3	3.1
Fentanyl			3	3.1
Methamphetamine			2	2.0
Prescription pain killers (e.g., Oxycodone)			5	5.1
Prescription stimulants (e.g., Adderall)			13	13.3
Prescription anti-anxiety (e.g., Xanax)			7	7.1
Other			1	1.0
Do not wish to answer			1	1.0

3.1.3. Substance use history

Participants (Table 2) reported past year use of alcohol (77.6 %), cannabis (73.5 %), tobacco/nicotine products (74.5 %), and psilocybin (33.7 %) in addition to less frequently used substances. Notably, 11.3 % of participants reported that they had been diagnosed with SUD by a clinician, whereas 51.6 % of participants reported believing that they currently or had previously met SUD criteria. At the time of participation, 40.2 % reported currently using kratom or kava to reduce drug use, including alcohol.

3.2. Subjective effects of kratom

Most participants (74 %) reported consuming multiple kratom doses during their bar visit, ranging between 1 and 8 drinks (Mean=2.73, SD=1.78). Approximately one quarter of participants (N = 12) reported consuming kava alongside kratom, ranging between 1 and 6.5 drinks (Mean=2.54, SD=1.56). Subjective effects of kratom are reported in Table 3.

Table 3.

Subjective effects of kratom.

Measure	Kratom		Kratom +  Kava
	M	SD	M	SD
DEQ
Liking drug effects	60.08	29.99	70.00	31.55
Wanting more of the drug	31.37	36.23	32.58	37.01
Feeling drug effects	31.34	23.80	24.83	21.14
Feeling high	20.03	25.39	28.83	34.69
Dizziness	9.61	21.13	4.42	7.83
Drug disliking	2.79	10.23	1.00	2.34
ARCI
Amphetamine	6.31	2.05	6.55	2.34
Morphine-Benzedrine	9.21	3.27	10.55	3.93
Pentobarbital-Chlorpromazine-Alcohol	2.85	2.96	1.70	2.06
BAES
Stimulating Effects	35.15	14.89	36.33	16.21
Sedating Effects	12.53	14.80	11.36	10.97

Note. DEQ =  Drug Effects Questionnaire; ARCI =  Addiction Research Center Inventory; BAES =  Biphasic Alcohol Effects Scale. Scale ranges: DEQ = 0–100; Amphetamine Scale = 0–11; Morphine-Benzedrine Scale = 0–16; Pentobarbital-Chlorpromazine-Alcohol Scale = 0–15; BAES Stimulating Effects = 0–70; BAES Sedating Effects = 0–70

3.2.1. Kratom only

Among participants who consumed kratom only, mean DEQ scores (0−100) were 60.08 (SD=29.99) for liking drug effects, 31.37 (SD=36.23) for wanting more of the drug, 31.34 (SD=23.80) for feeling drug effects, 20.03 (SD=25.39) for feeling high, 9.61 (SD=21.13) for dizziness, and 2.79 (SD=10.23) for drug disliking. On the ARCI, the mean for the Amphetamine Scale (0−11) was 6.31 (SD=2.05), the mean for the Morphine-Benzedrine scale (0−16) was 9.21 (SD=3.27), and the mean for the Pentobarbital-Chlorpromazine-Alcohol Scale (0−15) was 2.85 (SD=2.96). Mean Stimulating Effects (0−70) on the BAES was 35.15 (SD=14.89) and mean Sedating Effects (0−70) was 12.53 (SD=14.80).

3.2.2. Kratom and kava

Among participants who consumed both kratom and kava, mean DEQ scores were 70.00 (SD=31.55) for liking drug effects, 32.58 (SD=37.01) for wanting more of the drug, 24.83 (SD=21.14) for feeling drug effects, 28.83 (SD=34.69) for feeling high, 4.42 (SD=7.83) for dizziness, and 1.00 (SD=2.34) for drug disliking. On the ARCI, the mean for the Amphetamine Scale was 6.55 (SD=2.34), the mean for the Morphine-Benzedrine scale was 10.55 (SD=3.93), and the mean for the Pentobarbital-Chlorpromazine-Alcohol Scale was 1.70 (SD=2.06). Mean Stimulating Effects on the BAES was 36.33 (SD=16.21) and mean Sedating Effects was 11.36 (SD=10.97).

3.3. Perceived benefits of kratom use

During qualitative analyses of open-text responses (N = 92) related to perceived benefits associated with kratom, six themes were generated (Table 4).

Table 4.

Kratom benefits themes.

Themes	Codes
Theme 1: Mental Health	•Relaxation/stress relief (N = 46) •Mood enhancement/stabilization (N = 14) •Management of anxiety symptoms (N = 24) •Management of depressive symptoms (N = 3) •Overall/general mental health benefits without discussion of specific symptoms (N = 2)
Theme 2: Physical Health	•Pain relief and muscle relaxation (N = 23) •Anti-inflammatory (N = 1) •Sleep aid (N = 13) •Nausea relief (N = 1) •Sexual enhancement (N = 2) •Appetite suppression (N = 1) •Appetite stimulation (N = 1)
Theme 3: Recovery and Harm Reduction	•Replacement for other substances (N = 6) •Mitigation of craving (N = 3) •Relief of withdrawal symptoms (N = 1) •General sobriety and/or recovery benefits of kratom use without specifying a particular substance or recovery mechanism (N = 3)
Theme 4: Performance and Cognitive Enhancement	•Energy/stimulation (N = 12) •Motivation (N = 3) •Focus (N = 13) •Management of attention-deficit hyperactivity disorder (ADHD) symptoms (N = 1) •Mindfulness (N = 1)
Theme 5: Social Enhancement	•Social Enhancement (N = 26)
Theme 6: Drug Effects and Feeling High	•Drug effects and feeling high (N = 29)

3.3.1. Theme 1: mental health

Participants attributed mental health benefits to their kratom use, particularly use to relax and relieve stress (N = 46), enhance/stabilize mood (N = 14), and to self-manage anxiety (N = 24) and depressive symptoms (N = 3). Others reported overall benefits to their mental health without discussing relief of specific symptoms (N = 2).

“It takes away my anxiety (I was diagnosed with major anxiety and prefer to not be prescribed anything anymore due to addiction).”

“It helps with my anxiety and depression.”

“Kratom mainly helps boost my mood. It also relieves anxiety, calms me down while giving me energy.”

3.3.2. Theme 2: physical health

Participants also described using kratom to self-manage physical health symptoms, with pain relief and muscle relaxation (N = 23) frequently cited as a benefit of kratom use. One participant also described perceived anti-inflammatory properties of kratom. Additionally, participants shared that they used kratom as a sleep aid (N = 13), to relieve nausea (N = 1), and enhance sexual experiences (N = 2). Use of kratom to both suppress (N = 1) and stimulate (N = 1) appetite was also reported.

“Kratom helps a lot with the consistent back pain from my job it helps minimize the pain without the grogginess and other side effects from pain medication.”

“Kratom helps me with my chronic nausea and unknown stomach problems which allows me to eat.”

“It also helps me fall asleep and reduces my inflammation and pain.”

3.3.3. Theme 3: recovery and harm reduction

Participants shared experiences using kratom for harm reduction purposes or to support their sobriety or recovery (broadly defined) from other substances, including alcohol, opioids, and cannabis. In particular, participants reported using kratom as a replacement for other substances (N = 6), and to mitigate craving (N = 3) and withdrawal symptoms (N = 1). Several participants (N = 3) also shared sobriety and/or recovery benefits of kratom use, without specifying a particular substance or recovery mechanism.

“I enjoy the fact that when I drink kratom, I do not feel like drinking alcohol, which I have had issues with in the past.”

“It helps me keep away from other more harmful substances i.e. alcohol opioids.”

“First and foremost, kratom helped me a lot when I was going through withdrawals. It helped calm my body down, and kind of get rid of the effects … Kratom definitely helped save my life after addiction. It helps me get rid of cravings.”

3.3.4. Theme 4: performance and cognitive enhancement

Participants reported that using kratom increased their energy (N = 12), motivation (N = 3), and focus (N = 13), with one participant stating that they use kratom as self-management for attention-deficit hyperactivity disorder (ADHD) symptoms. Another participant also described increased mindfulness or ability to be present.

“Makes it easier to focus on schoolwork.”

“It also makes me feel more awake and motivated.”

“[I] feel more active and energetic after a few drinks.”

3.3.5. Theme 5: social enhancement

Social enhancement (N = 26) was described as another benefit of kratom, with participants reporting use of kratom to reduce social anxiety and increase their desire to socialize. Some participants also described improved quality of social interactions following kratom consumption and spoke to the sense of community afforded by the bars.

“Increase in desire to socialize, a positive outlook on how people will interact with me at a much higher rate than when I am not consuming Kratom.”

“Equally important is the community and environment. The people here make this space feel very welcoming in all aspects.”

“Socializing becomes way more intimate.”

3.3.6. Theme 6: drug effects and feeling high

Experiencing pleasant drug effects and feeling high was another commonly reported benefit of kratom use (N = 29), with feelings of “euphoria” frequently cited.

“General euphoria, feeling of ‘coziness’.”

“Euphoria, fuzzy feelings, and relaxed.”

3.4. Previous adverse reactions

During qualitative analyses of open-text responses (N = 71) related to prior experience of adverse reactions to kratom, three themes were identified (Table 5).

Table 5.

Kratom adverse reactions themes.

Themes	Codes
Theme 1: Acute Psychological Effects	•Anxiety (N = 1) •Irritability (N = 2) •Overstimulation (N = 1) •Unwanted dissociative effects (N = 4) •Unwanted intoxication effects (N = 2)
Theme 2: Acute Physical Health Effects	•Gastrointestinal symptoms (N = 61) •Dizziness and lightheadedness (N = 17) •Tachycardia (N = 1) •Muscle tension and weakness (N = 4) •Headache (N = 3) •Dehydration (N = 1) •Thermoregulation effects (N = 7) •Itchiness (N = 2) •Visual effects and psychomotor impairment (N = 2) •Impotency (N = 1) •Sleep disturbances (N = 4) •Generally “feeling sick” (N = 5)
Theme 3: Non-acute Adverse Reactions	•Withdrawal symptoms (N = 3) •Addiction to kratom (N = 1) •Irritability and mood swings after use (N = 1) •“Weird hangovers” (N = 1)

3.4.1. Theme 1: acute psychological effects

While participants shared mental health benefits attributed to their kratom use, adverse acute effects on mental health were also reported by some participants. In terms of psychological effects, participants reported acute adverse reactions to kratom that included anxiety (N = 1), irritability (N = 2), overstimulation (N = 1), and unwanted dissociative effects such as feeling “drowsy” or “out of it” (N = 4). Some participants also reported experiencing unwanted intoxication effects (N = 2).

“Sometimes I get extremely anxious and jittery on it.”

“I tend to feel spacey and out of it, about an hour after consuming.”

“Irritability is a common side effect”

“It can at times hit very strongly and the effects become a lot, but thankfully it levels out fairly quickly.”

3.4.2. Theme 2: acute physical health effects

Participants described a range of adverse physical reactions to kratom, with gastrointestinal symptoms (N = 61) such as nausea, vomiting, and constipation commonly reported. Participants also reported experiencing dizziness and lightheadedness (N = 17), tachycardia (N = 1), muscle tension and weakness (N = 4), headache (N = 3), and dehydration (N = 1). Thermoregulation effects (N = 7) were also reported, including overheating, sweating, and hyperhidrosis. Participants also described “feeling itchy” (N = 2), visual effects and psychomotor impairment (N = 2), impotency (N = 1), sleep disturbances (N = 4), and generally “feeling sick” (N = 5).

“Nausea at high doses. Constipation. Muscle tension (white kratom). Dehydration.”

“I’ve gotten too dizzy to drive when I accidentally have to much. I’ll get a very physical Ill feeling when to much is consumed ie weak muscles lack light headed the feeling like your gonna puke.”

“Dizziness, lack of sleep, impotency, nausea, headache.”

“Before a tolerance has been developed, I am prone to nausea and sweating. After a tolerance has been developed, rare upset stomach, very minor appetite changes Small decrease in fine motor coordination.”

3.4.3. Theme 3: non-acute adverse reactions

While participants were asked to report on prior experience of acute adverse reactions, some participants shared non-acute or longer-term adverse effects of kratom when responding to this question. Specifically, some participants reported experiencing kratom withdrawal symptoms (N = 3), which one participant described as similar to withdrawal from opioids. Participants also shared experiences of addiction to kratom (N = 1), irritability and mood swings after use (N = 1), and “weird hangovers” (N = 1).

“I have found that if I use Kratom every day (for 7 days or more) I may feel some slight withdrawal symptoms, such as difficulty sleeping, and restless legs. These withdrawal symptoms are similar to opioid withdrawal symptoms.”

“I also put myself down that I’m addicted to it. The problems aren’t negative effects when drinking it it’s what happens when I try not to drink it. I feel sick, I get head colds, body chills and aches. It’s a physically addictive substance that I wouldn’t hate if it becomes harder to get.”

“Mood swings when coming down. Occasional sleeping problems either too much or to little. Pretty bad withdrawal symptoms like head cold, stiff muscles, nausea, lack of appetite. But they generally subside with 2–3 days.”

4. Discussion

To our knowledge, this was the first investigation into the use of kratom in US-based ethnobotanical tea bars, which are becoming increasingly popular in the US. Here, we present the first data collected from individuals visiting these public consumption spaces.

4.1. Characterizing bar patrons

We found that participants visiting the bars in this study tended to be younger, with over half self-reporting a history of SUD. Additionally, 40 % reported using kratom or kava to reduce use of substances such as alcohol and opioids. We also found that the perceived benefits and reported adverse effects of kratom are diverse, warranting considerable further investigation.

4.2. Perceived benefits of kratom use

Our data indicate that kratom may play a role in non-abstinent recovery, with substitution for other drugs being a commonly reported reason for using kratom. The social and community dynamics of ethnobotanical tea bars merit considerable further study. Tea bars are often anecdotally cited as recovery spaces, but little is known about whether engagement with these bars is associated with long-term changes in substance use or changes in other clinical symptoms of addiction. Other kratom benefits noted by participants included supporting mental and physical health, boosting cognitive function, and facilitating social interaction. These findings are consistent with cross-sectional surveys and social media data, which suggest that since 2014, kratom use has increased in the US, as kratom is used more widely to improve mood and to self-manage anxiety, depression, and substance use disorders (e.g., alcohol, stimulant and opioid use disorders) (Grundmann et al., 2022, Smith et al., 2024b, Smith et al., 2022b, Smith et al., 2021b). Emerging data also show that recently, there has been a shift toward younger demographics engaging in kratom use for a variety of reasons including increased productivity, enhanced energy and cognition, and to facilitate physical performance (Smith et al., 2024b, Smith et al., 2023, Smith et al., 2022b).

4.3. Acute and long-term adverse reactions

Notably, most participants in this study reported consuming kratom frequently and visiting tea bars regularly. This is consistent with prior work showing that people in the US tend to dose 4–7 days per week and 2–3 times per day (Garcia-Romeu et al., 2020, Smith et al., 2024b, Smith et al., 2022c). Kratom use at this high frequency raises questions about possible dependence. Indeed, several participants in our sample reported symptoms of dependence, particularly withdrawal symptoms. Although Kratom Use Disorder (KUD) is not yet listed in the DSM-5, it is a documented phenomenon which has been shown to develop in some individuals who consume kratom regularly (Groff et al., 2022, Smith et al., 2022a). Emerging work suggests that KUD is generally mild in severity (Hill et al., 2024, Smith et al., 2022a), primarily driven by symptoms reflecting physical dependence (tolerance and withdrawal) and infrequently by social challenges (Smith et al., 2022a). More research is needed to determine whether bar patrons are at increased or decreased risk for development of KUD. It is also unknown whether individuals who qualitatively endorsed symptoms of KUD in the present study may have reported their experiences differently than participants without KUD symptoms. For example, individuals with tolerance to kratom may have consumed a greater number of drinks at the bar and reported fewer subjective drug effects, though KUD was not systematically assessed in the present work.

Gastrointestinal symptoms (e.g., nausea) were the most commonly reported acute adverse reaction to kratom. Other adverse reactions included acute psychological effects such as anxiety or irritability, which is notable given that relief from anxiety was also reported as a benefit of kratom use. It is unknown why kratom may be anxiogenic in some instances and anxiolytic in others, but this discrepancy points to the need for more research, particularly on acute effects. There is also limited data at present on the adverse effects of kratom, with most individuals who use kratom regularly reporting minimal adverse effects when using at their typical doses (Smith et al., 2024b, Smith et al., 2022c). Overall, findings are generally consistent with adverse side effects reported in prior work (Begum et al., 2024, Cinosi et al., 2015, Grundmann et al., 2023, Saingam et al., 2013, Singh et al., 2014). More work is needed to determine whether using kratom in a bar setting influences the likelihood of experiencing adverse effects.

4.4. Subjective effects of kratom

Finally, our participants reported experiencing stimulating, sedating, and euphoric effects after using kratom in a bar setting, with much stronger stimulating than sedating effects reported. Participants also reported consuming multiple kratom doses while at the bar. To our knowledge, there is only one small (N = 10) published human lab study evaluating acute subjective effects of commercial kratom (Smith et al., 2024c). This study found that among people who consume kratom regularly, typical doses of whole-leaf kratom produced mild subjective effects and minimal physiological and psychomotor changes (Smith et al., 2024c), consistent with our findings. These findings also align with subjective effects reported in prior ecological momentary assessment and survey-based studies, both in the US and Southeast Asia (Ahmad and Aziz, 2012, Singh et al., 2019, Smith et al., 2024b, Smith et al., 2022c, Suwanlert, 1975, Yang et al., 2023). However, additional work is needed to capture the full range of subjective effects experienced at different kratom doses and in different preparations, including co-mixtures of kratom with other psychoactive botanicals (e.g., kava).

4.5. Limitations and future directions

Data was collected from a single US state, from ethnobotanical tea bars surrounding a college campus, and from a sample that was limited in demographic diversity. Additionally, this study relied on participant self-report and was purely observational. Further, given that we did not analyze the alkaloid content of the products participants reported consuming during their bar visit, and given that this information was not listed on the menu for either bar, number of drinks consumed should be seen as a crude approximation of dosage. Moreover, the potency of the products participants reported consuming is unknown, posing a significant challenge in the assessment of subjective drug effects. It should also be noted that most individuals in the current study were engaged in regular kratom use, thus it is unclear how acute kratom exposure may impact the subjective drug experience of those who are kratom naïve or who use kratom infrequently.

Polysubstance use was a potential confound for all queried variables. Over half of participants reported consuming other substances (e.g., kava, cannabis) while self-administering kratom during their bar visit, which may have impacted subjective effects. Additionally, we only queried about the use of other substances as participants entered the bar (survey 1). Had we asked participants to report on the use of other substances as they exited the bar (survey 2), it is possible that responses may have varied from survey 1. Past-year use of other substances was also prevalent in the sample, which could have impacted participant responses to qualitative items about perceived benefits of kratom and prior experience of adverse reactions. Polysubstance use could have also impacted responses to items about the use of kratom for harm reduction purposes. For example, cannabis, which was commonly used by study participants, has also been show in some prior work to serve as a substitute for other substances (Karoly et al., 2021; Pince et al., 2025, Pince et al., 2025; Pince et al., 2025, Pince et al., 2025; Reiman, 2009).

Future studies may consider using urinalysis to confirm self-reported polysubstance use and exploring polysubstance use patterns in greater detail. Limitations highlight the need for more laboratory research on commercial kratom, as well as additional studies of kratom bar patrons from diverse communities across the US. Future work should also inquire about kratom consumption within other use settings (e.g., home, work, party), which could further inform our understanding of how context shapes use experiences. When possible, future studies may consider collecting product samples to determine the alkaloid content of the products participants report consuming, as additional work is needed to disentangle dose-dependent effects of kratom and how effects might vary across products with distinct alkaloid profiles. Additionally, while we asked participants about their history of SUD and use of kratom to reduce other substance use (e.g., alcohol, opioids), we did not query about treatment engagement, which should be evaluated in future work.

4.6. Conclusions and policy implications

Overall, this study provides valuable initial data characterizing the demographics and kratom use patterns of ethnobotanical tea bar patrons in Colorado. Additionally, findings provide further insight into the perceived benefits of kratom and commonly experienced adverse effects. Our data on the acute effects of kratom collected from individuals using in a bar setting is generally consistent with the limited prior work on the acute effects of kratom, and underscores its stimulant-like properties, with minimal intoxication/sedation reported. Finally, these data highlight the potential for ethnobotanical tea bars to serve as supportive social spaces for individuals in recovery from SUDs, warranting further study. Evidence-based policy and public health initiatives that weigh both benefits and risks of kratom are needed in the US to help regulate this increasingly popular botanical, as documented in the present study and prior work. Policies that promote quality control, safety, and informed consumption of kratom products (e.g., clear labeling of alkaloid content; testing) are urgently needed.

CRediT authorship contribution statement

Cianna J. Piercey: Writing – review & editing, Writing – original draft, Validation, Project administration, Methodology, Investigation, Formal analysis, Data curation, Conceptualization. Joseph Bunch: Writing – review & editing, Methodology, Formal analysis, Conceptualization. Joseph Cameron: Investigation, Conceptualization. Riley Ahern: Investigation, Conceptualization. Isabella Packwood: Investigation, Conceptualization. Carter Bruning: Investigation, Conceptualization. Devin Henry: Investigation, Conceptualization. Jesse Ruehrmund: Investigation, Conceptualization. Katelyn Weldon: Investigation, Conceptualization. Kirsten E. Smith: Writing – review & editing, Validation, Supervision, Methodology, Conceptualization. Hollis C. Karoly: Writing – review & editing, Writing – original draft, Validation, Supervision, Project administration, Methodology, Investigation, Formal analysis, Data curation, Conceptualization.

Ethics approval and consent to participate

The study was approved by the Institutional Review Board at Colorado State University. All individuals enrolled in the study consented to participate.

Author disclosure statement

Within the past three years, KES has served as a paid scientific advisor to the International Plant and Herbal Alliance and the Kratom Coalition and serves as an expert witness in legal cases involving kratom.

Funding

HCK is supported by the National Institute on Alcohol Abuse and Alcoholism of the National Institutes of Health (K23AA028238). KES is supported by the National Institute on Drug Abuse of the National Institutes of Health (R00DA055571). The content is solely the responsibility of the authors and does not necessarily represent the official views of the National Institutes of Health.

Declaration of Competing interest

The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: Kirsten Smith reports a relationship with International Plant and Herbal Alliance that includes: consulting or advisory. Kirsten Smith reports a relationship with Kratom Coalition that includes: consulting or advisory. Co-author serves as an expert witness in legal cases involving kratom - KES If there are other authors, they declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.

Data availability

Data and materials are available from the corresponding author upon reasonable request