Hair loss in athletic testosterone use in males: a narrative review

Abstract

Performance‐enhancing drugs, such as testosterone, are used by athletes and youth to increase muscle growth and strength, particularly among males. However, these therapies potentially pose health risks, including liver toxicity, gynecomastia, and hair loss. Testosterone use is rising for performance enhancement, physical appearance, and resistance training, but there remains an absence of standardized guidelines for safe dosages. This study examines the relationship between testosterone use and hair health in males, aiming to develop guidelines for safe, responsible testosterone use. Understanding treatment outcomes in this context is crucial for informed healthcare.

Introduction

The utilization of performance‐enhancing drugs extends beyond the realm of professional athletes, presenting among the youth population as well. Among the array of substances utilized, common agents include androgenic and anabolic steroids (AAS), polypeptide hormones with anabolic properties, stimulants, and diuretics. Injectable forms, such as testosterone enanthate and cypionate, have intermediate half‐lives of about 1 week. In contrast, testosterone undecanoate is notable for its significantly longer half‐life of approximately 3 months, allowing for less frequent dosing intervals. ¹

Testosterone supplementation is associated with a dose‐dependent increase in myonuclear and satellite cell numbers, which are critical for muscle growth. ² , ³ , ⁴ Elevated serum testosterone concentrations promote muscle hypertrophy, enhance strength development, and reduce total body adipose tissue. ⁵ , ⁶ Despite these benefits, there is no established standard dose or safety protocol. Reports suggest the use of various supraphysiological doses, ranging from 50 to 2000 mg per week, with some individuals maintaining this regimen for up to 25 years. ⁷ However, the specific type or formulation of testosterone remains ambiguously defined.

Testosterone replacement therapy carries numerous potential risks, including worsening of symptoms related to benign prostatic hypertrophy, liver toxicity and tumor development, gynecomastia, erythrocytosis, testicular atrophy and infertility, exacerbation of sleep apnea, and dermatologic conditions such as hair loss. ⁸ , ⁹ The psychological ramifications of hair loss include diminished self‐confidence, lowered self‐esteem, and increased self‐consciousness among affected individuals. ¹⁰ , ¹¹ This issue can particularly concern those focused on physical appearance and body shaping.

Identifying certain physical features can facilitate recognition of individuals using AAS in clinical settings. These include a lean and muscular physique characterized by a fat‐free mass index greater than 26 kg/m² and body fat less than 10%. However, the most effective diagnostic approach remains direct inquiry regarding AAS use. ¹²

We aim to explore the multifaceted relationship between testosterone use and hair health among males, hoping to contribute to the development of evidence‐based guidelines for safe and responsible testosterone use, safeguarding individuals' health and well‐being while optimizing their physical performance and appearance.

Materials and methods

In this narrative review, we conducted a non‐systematic search of the literature using PubMed, Embase, Web of Science, and Google Scholar. Our goal was to provide a broad overview of hair loss associated with testosterone and AAS use in male athletes. We included key studies published in English that focused on testosterone‐induced androgenetic alopecia (AGA), AAS use in athletes, and hair‐related side effects of AAS use. Studies were selected based on their relevance to the topic, specifically those that contributed to understanding the relationship between testosterone use, AGA, and the hair‐related side effects of anabolic‐androgenic steroid (AAS) use in athletes. We also prioritized studies based on recency, focusing on research published between 2001 and 2023. Studies that did not directly address hair loss or testosterone/AAS use were animal‐based, not published in English, or focused on non‐athlete populations were excluded. After applying these inclusion and exclusion criteria, a total of 33 articles were included in the review.

Testosterone and AGA

Testosterone, a cornerstone hormone in male physiology, exerts significant influence through its conversion to dihydrotestosterone (DHT) via the enzyme 5α reductase or aromatization to estrogen. ¹³ Both testosterone and DHT predominantly bind to intracellular androgen receptors, primarily located within the dermal papilla and hair bulb, with DHT exhibiting approximately five times greater affinity. This disparity suggests that DHT plays a pivotal role in the pathogenesis of AGA. ¹⁴ , ¹⁵

AGA, a prevalent pathological condition, manifests as the progressive miniaturization of hair follicles. In males, this process is primarily driven by the accelerating effects of DHT on cellular mitosis within the matrix. ¹⁶ , ¹⁷ This phenomenon results in a shortened period of cellular differentiation, ultimately leading to diminished hair follicle size and functionality. ¹⁷ The androgen signaling pathway also contributes to the miniaturization of hair follicles through mechanisms such as upregulation of androgen receptor expression, heightened androgen sensitivity facilitating greater affinity for steroid ligands, and elevated levels of 5α‐reductase. ¹⁶ Collectively, these molecular events underpin the complex pathophysiology of AGA, highlighting the multifaceted role of androgens in hair follicle biology. Moreover, AGA is associated with an increase in telogen shedding, characterized by a higher number of hair follicles in the telogen phase per unit of time. ¹⁷ In combination, these factors perpetuate the thinning of hair over time.

Serum testosterone level and hair loss

The association between testosterone levels and hair loss has been investigated through various studies with inconclusive results. A case–control study involving 315 male subjects categorized participants into groups of no hair loss, frontal baldness, and vertex baldness. ¹⁸ Interestingly, they found no statistically significant differences in total testosterone, free testosterone, or DHT levels between the frontal baldness and no hair loss groups. However, the vertex baldness group exhibited significantly higher total testosterone and free testosterone levels (295 ± 97 ng/dl; 16.5 ± 5.5 ng/dl) compared to the no hair loss group (276 ± 89 ng/dl, P = 0.039; 14.8 ± 4.7 ng/dl, P = 0.004).

Similarly, another study measured androgenic steroid levels in 22 participants with hair loss and 11 control subjects. ¹⁹ The hair loss group exhibited significantly higher testosterone levels with a mean of 4.36 ng/ml (range, 3.19–5.83 ng/ml), compared to the control group's mean of 3.05 ng/ml (range 2.06–4.36 ng/ml, P < 0.001). Additionally, DHT concentrations were significantly elevated in the hair loss group, with a mean of 71.84 ng/ml (range, 20.50–221.08 ng/ml), versus the control subjects, with a mean of 1.41 ng/ml (range, 0.45—2.40 ng/ml, P < 0.001).

In contrast, Narad et al. conducted a study involving 50 men who experienced severe premature balding before the age of 30. ²⁰ These men were compared to an equal number of age‐matched control subjects. The serum levels of testosterone and dehydroepiandrosterone sulfate (DHEAS) were measured, and no significant statistical differences were found between the two groups. However, it was observed that the serum sex hormone‐binding globulin (SHBG) levels in AGA cases (10.21 ± 3.22 nmol/l) were significantly lower than in the control group (32.70 ± 27.35 nmol/l, P = 0.007).

Similarly, a case–control study involving 57 and 32 controls revealed that serum testosterone levels in AGA cases (24.61 ± 7.97 nmol/l) were significantly higher compared to the control group (20.57 ± 4.93 nmol/l, P = 0.040). ²¹ Serum DHEAS levels in AGA cases (3.63 ± 2.19) were also considerably higher than in the control group (2.64 ± 1.49, P = 0.020). However, serum SHBG levels were significantly lower in AGA cases (35.07 ± 11.11) than in the control group (46.41 ± 14.03, P < 0.001).

A large cross‐sectional, population‐based study in Northeastern Germany recently investigated a cohort of 373 men. ²² The study's findings revealed no significant association between hair loss and levels of total testosterone (relative risk, RR = 0.77; 95% CI: 0.96–1.04), free testosterone (RR = 0.98; 95% CI: 0.94–1.01), or androstenedione (RR = 0.96; 95% CI: 0.93–1.00). However, the levels of DHEAS were lower in cases with hair loss compared to those without hair loss (RR = 0.98; 95% CI: 0.94–1.03; P = 0.001).

Overall, while some studies suggest a correlation between higher testosterone levels and specific hair loss patterns, others fail to find a significant association. Furthermore, SHBG and DHEAS appear to be relevant in certain studies, although their role remains incompletely understood, indicating an intricate and multifactorial nature of the relationship between testosterone and hair loss.

AAS use in athletes

The global prevalence of AAS use among male athletes is estimated at approximately 3.3%, with an overall lifetime prevalence of AAS use in men reaching around 6%. Recent research suggests an even higher prevalence among athletes seeking performance enhancement. For example, a decade‐long Canadian study revealed that 10.9% of 964 patients undergoing bilateral gynecomastia surgery were AAS users. ²³ Moreover, a recent study in Iran following the COVID‐19 pandemic reported a noteworthy surge in AAS use among individuals engaged in resistance training. ²⁴ This cross‐sectional survey of 3603 participants showed strikingly high rates, with 53.05% of male participants reporting AAS use. Among male users, 29.47% used testosterone specifically. ²⁴

Adolescents and young adults are particularly notable for engaging in AAS use for performance enhancement, highlighting a concerning trend with implications for both individual health and broader public health. ⁷ These findings underscore the evolving landscape of AAS use across diverse populations worldwide, emphasizing the need for comprehensive strategies in prevention and intervention efforts.

Of note is that the World Anti‐Doping Agency (WADA) prohibits elite athletes from using many medications. This includes numerous medications with dermatologic indications. Anabolic steroids may rarely be used for the purpose of wound healing; however, their use is generally prohibited and would require thorough justification to be utilized. ³⁰ Given that anabolic steroids are often prohibited, hair samples may offer a possible tool for testing and moderation of use in athletes. However, hair analysis for anabolic steroids faces significant challenges, as these substances are poorly incorporated into hair, making detection difficult, especially for single doses. While hair testing can sometimes document long‐term anabolic steroid use, it remains unreliable for precise detection and interpretation, limiting its utility in doping control. ³¹ , ³² , ³³

Hair‐related side effects of AAS use

Prior reports and studies have documented the potential for hair‐related side effects from AAS use. For example, a study reported a case of a man in his thirties who developed AGA one year after starting supplementation with human chorionic gonadotropin for weight loss, followed by testosterone hormone pellet implantation. ²⁵ Despite these interventions, the patient did not experience any weight loss from dietary changes. A physical examination revealed male‐pattern hair loss, classified as Norwood Hamilton Stage III.

A qualitative study assessed the intentions, perceptions, and safety concerns of AAS among Jordanian gym users. ²⁶ A majority of participants reported numerous adverse side effects associated with AAS use, including hair loss. Similarly, Smit et al. conducted a quantitative 1‐year prospective cohort study in the Netherlands using self‐reported data from 100 men. ²⁷ Initially, 2% of participants reported alopecia and no increased hair growth. However, roughly 3.5 months later, reports of alopecia rose to 12% by the final week of the AAS cycle, with 5% of participants reporting increased scalp hair growth.

In contrast, Almohammadi et al. conducted a cross‐sectional survey of males in Saudi Arabia engaged in resistance training using a self‐administered questionnaire. ²⁸ Of the 120 participants, 20% reported using hormonal supplements, and 2 participants (1.67%) experienced increased hair growth, although the specific location of the hair increase was not specified.

The prevalence of alopecia among AAS users may be underreported. Heerfordt et al. conducted a nationwide anti‐doping initiative within Danish fitness establishments from 2006 to 2018, involving 1189 male AAS users and 11,890 controls. ²⁹ This investigation revealed that fewer than five AAS users reported alopecia, a figure potentially influenced by privacy considerations. These findings underscore the need for additional studies to ascertain the true magnitude of hair‐related side effects among AAS users.

Limitations

Determining the prevalence or incidence of hair loss among AAS users presents several challenges (Table 1). A significant limitation is the reliance on self‐reported data, which can be inherently biased and inaccurate. Additionally, many studies fail to specify the type of hair loss experienced, whether it be AGA, telogen effluvium, or other forms of alopecia. This ambiguity makes it difficult to discern whether observed hair loss is a normal shedding process or directly related to AAS use. Furthermore, the temporal association between the onset of hair loss and AAS use is often inadequately clarified.

Table 1.

Prevalence of hair‐related side effects in users of androgenic and anabolic steroids

Study	Location	Study design	Main findings
Griggs et al. 25	United Stated	A case report	A man in his 30s was diagnosed with androgenetic alopecia 1 year after he started supplementation with human chorionic gonadotropin for weight loss, which was followed by the implantation of testosterone hormone pellets
Smit et al. 27	The Netherlands	A prospective cohort	100 males using AAS By the final week of the AAS cycle, approximately 3.5 months in, reports of alopecia increased to 12% from an initial 2%
Almohammadi et al. 28	Saudi Arabia	A cross‐sectional study	120 males using AAS 1.67% experienced increased hair growth
Heerfordt et al. 29	Denmark	A retrospective study	1189 male AAS users and 11,890 controls Alopecia in <5 AAS users and <5 controls

Studies focusing on testosterone use in transgender individuals were excluded.

AAS, androgenic and anabolic steroids users.

Previous research has also been inconsistent in specifying the type of serum testosterone levels measured, utilizing various units and methods of analysis. This inconsistency hinders the ability to conduct meta‐analyses. Additionally, there has been a lack of focus on the relationship between serum testosterone levels and the severity of hair loss. The correlation between testosterone dosage, duration of use, and cumulative dose with the severity of AGA and TE remains unexplored.

Future research should aim to clarify these aspects, which could significantly aid in patient education regarding testosterone use. Furthermore, studies are lacking on the efficacy of available hair loss medications, such as finasteride and minoxidil, in preventing hair loss among AAS users, especially those on high doses of testosterone. It remains uncertain whether the effectiveness of these treatments in AAS users is comparable to that in patients not using AAS. This gap in understanding treatment outcomes highlights a crucial area for further investigation.

Further, this review focuses exclusively on AAS use in males. The mechanism and hormone pathways of hair loss in females differ. Therefore, further reviews of AAS use within the female population are warranted.

Conclusion

The use of testosterone has been rising for various reasons, including performance enhancement, physical appearance, and resistance training. Despite its widespread use, no established standard or safe dosage remains for enhancing muscle hypertrophy and fat loss for improved body shaping. This absence of standardized guidelines poses significant risks, particularly regarding potential adverse effects such as cutaneous cosmetic conditions like hair loss, which remain a prominent concern.

Existing research predominantly relies on self‐reported data from participants, introducing biases and limitations in understanding the true scope and impact of testosterone use on hair health. Consequently, there is a pressing need for further investigation to elucidate the nuanced relationship between testosterone use and patterns of associated hair loss.

Comprehensive studies are essential to delineate better the multifaceted interplay between testosterone supplementation and hair health. This research will inform clinical practice and public health initiatives aimed at mitigating the adverse consequences associated with testosterone use. Moreover, these efforts can contribute to developing evidence‐based guidelines for safe and responsible testosterone use, safeguarding the health and well‐being of individuals seeking to optimize their physical performance and appearance.

Supporting information

Table S1. Common types of androgenic and anabolic steroids (AAS) used by individuals for enhancement purposes.

Table S2. Recommended dosages of common types of androgenic and anabolic steroids for men, as suggested by the online community, for enhancement purposes.