Table 2.

Effects of essential oils on physiological responses.

Author	Essential Oils	Application Methods	Measures	Outcomes
Du et al. [13]	lemon and grapeseed	inhaled	cognitive function tests	shortened reaction time response, more impulsive decision-making
Dehghan et al. [14]	lavender, rosemary, and orange	inhaled	retrospective and prospective memory scale	only lavender or rosemary can reduce some memory problems in hemodialysis patients by reduction of retrospective memory problems
Sgoifo et al. [19]	Juniperus phoenicea gum extract, Copaifera officinalis (Balsm Copaiba) resin, Aniba rosaeodora (Rosewood) wood oil and Juniperus virginiana oil	dermal	psychological questionnaires (anxiety, perceived stress, and mood profile), autonomic parameters (heart rate (HR) and heart rate variability (HRV)), and neuroendocrine (salivary cortisol) measurements	stress resilience due to favorable physiological, neuroendocrine, and psychological effects
Schneider [21]	peppermint, rosemary, grapefruit, and cinnamon	inhaled	vigilance test using computerized attention and concentration tests	improved vigilance
Manor et al. [23]	lavender	inhaled	electroencephalogram (EEG)	distinct anxiolytic-like effects and sleep enhancing purpose
Ko et al. [24]	lavender	inhaled	sleep laboratory: EEG, electromyogram (EMG) and electrooculogram (EOG) signals	improved subjective and objective sleep qualities
Kawai et al. [30]	grapefruit	inhaled	muscle sympathetic nerve activity (MSNA), blood pressure (BP), heart rate (HR), and cortisol concentration	changed in BP, muscle sympathetic nerve activity changed, decreased stress hormone (cortisol) concentration
Park et al. [35]	lavender, peppermint, and coffee	inhaled	quantitative and objective EEG and the questionnaire	stabilized for lavender and aroused for peppermint and coffee
Vital et al. [38]	oregano and rosemary	inhaled/oral	a 9-point scale	higher consumer acceptance and willingness to buy
Moss et al. [42]	rosemary	oral	computerized cognitive tasks	enhance cognition
Montibeler et al. [43]	lavender and geranium	massage	biophysiological and psychological parameters	reduction in heart rate and blood pressure levels after massage sessions
Kennedy et al. [44]	spearmint and peppermint	oral	neurotransmitter receptor binding, acetylcholinesterase (AChE) inhibition, mood scales, and standardized cognitively demanding tasks	peppermint with high levels of menthol characteristic as in vitro cholinergic inhibitory, calcium regulatory, GABA/nicotinic binding/modulated performance on demanding cognitive task/attenuated the increase in mental fatigue associated with extended cognitive task
Brnawi et al. [46]	cinnamon bark and leaf	oral	a 9-point hedonic scale	natural antimicrobial ingredient in milk beverages—sensory aspect
Matsumoto et al. [48]	yuzu and lavender	inhaled	heart rate variability and the profile of mood states (POMS) questionnaire	alleviated premenstrual emotional symptoms and improved parasympathetic nervous system activity
Huang and Capdevila [6]	petitgrain	inhaled	the stait–trait anxiety inventory (STAI) questionnaire, POMS questionnaire, and HRV	improved performance in the workplace-autonomic balance, reduced stress level, and increased arousal level-attentiveness-alertness
Goepfert et al. [51]	lemon and lavender	inhaled	physiological parameters: respiratory rate (RR), heart rate (HR), systolic (SBP) and diastolic pressure (DBP)	lemon increased RR, HR, DBP, and lavender decreased RR
Forte et al. [52]	oregano	oral	sensory analysis of the consumer tests	improved consumer perception of the meat quality
Chen et al. [53]	lavender	massage	salivary cortisol and immune function measurements	decreased stress and enhanced immune function
Watanabe et al. [58]	bergamot	inhaled	salivary cortisol level	lower salivary cortisol compared to rest
Chen et al. [61]	Meniki and Hinoki wood	inhaled	subject’s BP, HR, HRV, sympathetic and parasympathetic nervous system (SNS and PSNS), and POMS questionnaire	simulated a pleasant mood status-regulators of sympathetic nervous system dysfunctions
Bikmoradi et al. [62]	lavender	inhaled	DASS-21 questionnaire, HR, RR, SBP and DBP	no effects on mental stress and vital signs in patients following coronary bypass surgery (CABG), but has possibly significant effect on systolic blood pressure of patients
Nagata et al. [63]	bergamot	inhaled	a visual analog scale	showed little effect on pain, discomfort, vital signs, as well as preferred music and aroma during the next computed tomography (CT)
Matsumoto et al. [64]	yuzu	inhaled	POMS questionnaire and salivary chromogranin A	alleviated negative emotional stress-suppression of sympathetic nervous system activity
Koteles and Babulka [65]	rosemary, lavender, and eucalyptus	inhaled	EEG, HR, BP, HRV and self-reported questions and statements alertness, pleasantness, expectations, and perceived effect	no effect on any assessed variables (HR, BP, and HRV) and perceived subjective changes-non-conscious states
Igarashi et al. [67]	rose	inhaled	HRV and subjective evaluations	induced physiological–psychological relaxation
Baldinger et al. [68]	lavender	oral	positron emission tomography (PET) and magnetic resonance imaging (MRI) measurements	the anxiolytic effects of Silexan via serotonin-1A receptor
Igarashi [72]	lavender, petitgrain, and bergamot	inhaled	POMS questionnaire and autonomic nervous system parameters	no major differences observed between the two groups but essential oils containing linalyl acetate and linalool effective for the POMS and parasympathetic nerve activity based on an intragroup comparison
Brito et al. [75]	citronellol	paw injection	nociceptive test	attenuated orofacial pain
Son et al. [33]	sweet marjoram and sweet orange	inhaled	participants’ Foley catheterization skill, the Korean version of the revised test anxiety scale, and a numeric rating score	improved the performance of fundamental nursing skills and reduced anxiety and stress