Libido & Sexual Vitality (Men's)

Libido and Sexual Vitality in Men: A Nutrition and Natural-Health Reference

Definition and Overview

Libido refers to sexual desire — the motivational, cognitive, and biological drive that initiates and sustains sexual interest and behaviour. In the broader context of male sexual vitality, libido intersects with arousal, erectile function, ejaculatory capacity, and overall reproductive well-being. Male sexual function is an absolute prerequisite for species perpetuation because it allows semen deposition within the female vagina; however, in humans, normal sexual functioning is also an important part of couple relationships, allowing for the exchange of intimacy and pleasure between two partners.

Male sexual dysfunction is a series of conditions, most notably including erectile dysfunction (ED), Peyronie's disease, and premature ejaculation, defined by impaired sexual functioning. The prevalence of male sexual dysfunction increases with age and is relatively high, with greater than 50% of men aged 40 to 70 describing some degree of erectile dysfunction. Among men with sexual dysfunction, reduced sexual desire is the most important correlate of male hypogonadism.

Body Systems Involved

The Endocrine System

Libido, or sexual desire, is significantly influenced by testosterone, which regulates various brain regions involved in sexual motivation, including the hypothalamus; in men, testosterone plays a crucial role in sexual desire and arousal. Beyond these physical advantages, testosterone plays a crucial role in male reproductive health by affecting spermatogenesis, libido, and erectile function. The development and maintenance of muscular mass, bone density, and general physical strength depend heavily on testosterone, a hormone that plays a complicated and significant role in men's physiology.

Several animal and human studies have implicated the pivotal role of testosterone in regulating the physiological pathways underlying sexual desire. Functional imaging studies have identified several regions in the brain that are activated by sexual stimuli and these androgenic pathways. A strong correlation between serum testosterone levels and libido in men has been reliably and repeatedly demonstrated.

The Nervous System

In general, similar to most diseases, erectile dysfunction can be attributed to vasculogenic, neurogenic, or endocrinological disorders. The central nervous system mediates the processing of sexual stimuli and the initiation of desire, while the peripheral nervous system coordinates penile vascular responses. Risk factors for male sexual dysfunction include age, diabetes mellitus, cancer, stroke, hypertension, penile trauma, depression, anxiety, and disturbance in central serotonin neurotransmission and 5-HT postsynaptic receptor functioning.

The Cardiovascular System

Sexual dysfunction can be an early warning sign of hidden cardiovascular disease in men who otherwise appear healthy. Many studies show that cardiovascular diseases and sexual dysfunction often occur together and share similar risk factors such as high blood pressure, diabetes, smoking, aging, and obesity. Testosterone plays a vital role in vascular health by improving endothelial function, which is crucial for maintaining cardiovascular health in men.

The Psychological Domain

A systematic review of 67 studies found that cognitive-processing factors make a major contribution to sexual dysfunction in both women and men. In particular, performance worry — before, during, and after sexual activity — is a significant contributor. Sexual dysfunction is a significant public health problem often contributing to other adverse mental health sequelae, including low self-esteem, anxiety, and depression.

Contributing and Associated Factors

Age and Hormonal Decline

Gradual age-related decline in testosterone levels is associated with decreased libido and reduced testicular function. Sexual function and testosterone levels progressively decline in aging men. Associated morbidities and metabolic disorders can accelerate the phenomenon.

Metabolic and Chronic Disease

The most important correlates of low testosterone in subjects with sexual dysfunction are metabolic disturbances, including obesity, metabolic syndrome, and type 2 diabetes mellitus, most probably because they are associated with metaflammation of hypothalamic centres known to regulate reproductive function. Risk factors for male sexual dysfunction include age, diabetes mellitus, cancer, stroke, hypertension, penile trauma, depression, anxiety, and disturbance in central serotonin neurotransmission and 5-HT postsynaptic receptor functioning.

Psychological and Relational Factors

Psychological factors such as fear, despair, and anxiety greatly affect patients' sexual lives and thus contribute to the incidence of sexual dysfunction. In older people, lifestyle changes occurring with advancing age — including the death of their partner, worsening of social status, deterioration of support networks, and health and finance-related family problems — might contribute to sexual difficulties. This change, by inducing and contributing to the development of depressive and anxiety symptoms as well as couple health perturbation, can in turn worsen and aggravate the cardiovascular risk profile.

Cancer Treatment

Damage to sexual function or fertility is usually linked to cancer treatments, such as chemotherapy, radiotherapy, and surgery, which can directly aggravate sexual dysfunction or influence various links associated with it, such as hormone disorder, nerve damage, and vascular injury of the penis. Sexual dysfunction in cancer patients is not only due to the disease itself but also to the comprehensive result of anaemia, anorexia, muscle atrophy, and nerve damage.

Note on the Complexity of Causation

Testosterone is deeply involved in every step of the male sexual response. However, the occurrence of sexual disorders cannot be automatically related to a decline in testosterone levels. The specific contribution of low testosterone to sexual function impairment in aging men has still not been completely clarified.

Nutrients Studied in Relation to Male Libido and Sexual Vitality

Zinc

Overview: Zinc is an essential trace mineral with well-documented roles in testosterone biosynthesis and reproductive health.

Scientific Evidence: To date, mainstream published studies have shown a negative effect of zinc deficiency on male testosterone levels and a positive effect of zinc supplementation on serum testosterone. A systematic review covering clinical and animal studies concluded that zinc deficiency reduces testosterone levels and zinc supplementation improves testosterone levels. Furthermore, the effect of zinc on serum testosterone may vary depending on basal zinc and testosterone levels, zinc dosage form, elemental zinc dose, and duration. Serum zinc was positively correlated with total testosterone, and moderate supplementation plays an important role in improving testosterone levels. Although the number of studies on the effect of serum zinc on testosterone is limited, the current results have shown a positive relationship between serum zinc and male testosterone. Evidence is strongest in zinc-deficient populations; effects in men with adequate zinc status are less clearly established.

Vitamin D

Overview: Vitamin D functions as a steroid hormone precursor and has receptors in testicular tissue. Population studies have reported associations between vitamin D status and testosterone levels.

Scientific Evidence: The mechanisms underlying vitamin D's effects on testosterone involve both direct actions on testicular tissue and indirect effects through calcium metabolism. A rigorously designed randomized controlled trial (the Graz Vitamin D&TT-RCT) investigated this association directly: it was a single-centre, double-blind, randomized placebo-controlled trial conducted at the Medical University of Graz, Austria, involving 100 healthy men with low serum total testosterone and low vitamin D levels. Subjects received 20,000 IU of vitamin D3 per week or placebo for 12 weeks. Ninety-four men completed the study, and the investigators found no significant treatment effect on testosterone, indicating that in men with low-normal testosterone but not severe deficiency, vitamin D supplementation alone may not reliably raise testosterone. The association between vitamin D deficiency and erectile dysfunction has also been reported in NHANES cross-sectional data, though cross-sectional studies cannot establish causality.

Magnesium

Overview: Magnesium is a cofactor in hundreds of enzymatic reactions, including those involved in steroidogenesis. Magnesium, selenium, and various B vitamins also contribute to optimal testosterone production through their roles as enzymatic cofactors. A 2020 systematic review and meta-analysis published in Nutrients examined the effects of dietary or supplementary micronutrients on sex hormones in middle and older age, providing broader context for the role of minerals including magnesium in hormonal regulation. Evidence in humans remains preliminary and largely observational.

Selenium

Overview: Selenium is a trace mineral critical to antioxidant enzyme function, particularly glutathione peroxidase. Selenium is a trace mineral important for the antioxidant enzyme glutathione peroxidase in sperm. Selenium helps protect sperm from oxidative damage and is needed for proper sperm maturation. Evidence of a direct effect on libido or sexual desire per se in human clinical trials is limited; most selenium research in male reproductive health has focused on sperm quality.

L-Arginine

Overview: L-arginine is a semi-essential amino acid and the principal precursor of nitric oxide (NO), a vasodilator essential for penile smooth muscle relaxation and erection. Walnuts, a staple of the Mediterranean diet, are rich in L-arginine, a precursor of nitric oxide, and alpha-linolenic acid. Both compounds contribute to the anti-hypertensive and anti-atherogenic properties of the diet. Clinical evidence in the context of erectile function is mixed; L-arginine has been studied in combination products (e.g., combined with L-citrulline, L-carnitine, magnesium, and zinc) with some positive outcomes in small trials, but robust standalone trials demonstrating improvement in libido per se are limited.

Herbs and Botanical Ingredients Studied in Relation to Male Libido and Sexual Vitality

Ashwagandha (Withania somnifera)

Traditional Use: Ashwagandha is a traditional Indian Ayurvedic remedy and adaptogen, traditionally used to improve sexual dysfunction in men and women. In classical Ayurvedic texts it is classified as a rasayana (rejuvenating tonic) and has been used for centuries in the form of root powder preparations, typically administered with milk or ghee, to promote vitality, strength, and reproductive health.

Scientific Evidence: A possible mechanism by which ashwagandha improves sexual performance could be its interaction with GABA receptors, which in turn may enhance the expression of gonadotropin-releasing hormone (GnRH). Furthermore, ashwagandha may influence the reproductive system and fertility through its withanolides — steroidal lactone triterpenoids that share a structural similarity with testosterone.

A key RCT examined the KSM-66® extract: a study in 46 infertile men with a mean age of 34 years found that supplementing with 675 mg/day of KSM-66® was associated with a significant increase in testosterone concentrations (17.3% increase) after 90 days compared with the placebo group (3.8% increase; P < 0.01). However, one study using a different extract (Shoden®, 240 mg/day for 60 days) examined 60 stressed healthy men and women with a mean age of 41 years and found no statistically significant difference in testosterone concentrations in male participants (n=19) compared with the placebo group after 60 days of treatment.

In a more recent prospective, randomized, double-blind, placebo-controlled study evaluating an ashwagandha root extract (ARE) on sexual health in healthy men over 8 weeks, total testosterone levels were comparable at baseline, and by Week 8 the increase in the ARE group did not differ significantly from placebo (p = 0.223). A systematic review by Smith et al. of the effects of 13 herbs on testosterone concentration concluded that fenugreek and ashwagandha have positive effects on testosterone concentrations in men. Overall, the evidence is mixed and largely preliminary, with positive signals from some but not all RCTs. Sample sizes are generally small, and populations differ across trials.

Maca (Lepidium meyenii)

Traditional Use: Between 1,300 and 2,000 years ago, the Andean population appreciated the maca plant for its nutritional and therapeutic properties and its positive effect on male and female reproductive functions, sexual functions, osteoporosis, depression, anxiety, and energy. Maca is an Andean plant of the brassica (mustard) family, traditionally cultivated at high altitudes in Peru and consumed as a food root, fermented drink, or dried powder.

Scientific Evidence: A systematic review searched 17 databases and included all randomised clinical trials comparing any type of maca to placebo for healthy people or patients with sexual dysfunction. The risk of bias for each study was assessed using Cochrane criteria. Four RCTs met all inclusion criteria. Two RCTs suggested a significant positive effect of maca on sexual dysfunction or sexual desire in healthy menopausal women or healthy adult men, respectively, while one RCT failed to show any effects in healthy cyclists. A further RCT assessed effects in patients with erectile dysfunction using the IIEF-5 and showed significant effects.

Clinical studies, primarily focused on sexual health, indicate improved sexual desire, erectile function, and subjective wellbeing in men. Importantly, the available evidence indicates that maca's effects on sexual desire appear to be independent of changes in testosterone levels. Notably, all studies examining the effect of maca on testosterone concentrations have not demonstrated reliable increases. Three RCTs showed mixed efficacy of maca in improving semen quality parameters; a meta-analysis also failed to show efficacy in increasing sperm concentration compared to placebo (weighted mean difference 2.22, 95% CI −2.94 to 7.37, p = 0.4). The overall evidence base remains limited by small sample sizes, heterogeneous populations, and short follow-up durations.

Tribulus (Tribulus terrestris)

Traditional Use: Tribulus terrestris (puncture vine) has a long history of use in Traditional Chinese Medicine and Ayurveda, where it was used for urogenital complaints and as a general tonic to promote vitality. In Eastern European folk medicine, preparations of the aerial parts were also used for various conditions.

Scientific Evidence: Tribulus terrestris has been claimed to increase testosterone levels and improve sexual function, particularly erectile dysfunction. A systematic review aimed to evaluate the effectiveness of TT supplementation in improving sexual function and serum testosterone levels in men. After searching the literature, 10 studies were eligible for the review, comprising 9 clinical trials and 1 quasi-experimental study. The Jadad score revealed low methodological quality for 50% of the studies. The conclusion was clear: TT supplementation has a low level of evidence regarding its effectiveness in improving erectile function in men with erectile dysfunction, and no robust evidence was found for increasing testosterone levels. A systematic review on all tribulus studies examining various forms of testosterone in animals and humans concluded that the evidence indicated that it is ineffective at increasing testosterone concentrations in humans. One trial using 1.5 g of a tribulus extract (Tribestan) daily in 180 men for 12 weeks showed no significant difference in testosterone concentrations between groups. Tribulus remains one of the most investigated, yet least well-supported, botanical supplements in this category.

Tongkat Ali / Longjack (Eurycoma longifolia)

Traditional Use: Eurycoma longifolia Jack (Tongkat Ali or Malaysian ginseng) has been traditionally used for management of male sexual dysfunction and infertility. Also named Tongkat Ali by locals in Malaysia, it is a well-known botanical drug used as an aphrodisiac. Traditionally, the bitter root was decocted in water and consumed as a tonic drink, or prepared as a water-extracted powder.

Scientific Evidence: E. longifolia is reported to improve libido and is being used as a common ingredient in more than 700 herbal or nutraceutical products marketed as aphrodisiacs. Eurycoma longifolia contains biologically active substances (eurycomanones and eurycomanols) that may inhibit the conversion of testosterone to estradiol by the aromatase enzyme, thereby increasing testosterone levels. A systematic review and meta-analysis of clinical trials found a positive signal for effects on serum total testosterone. One systematic review did not classify Tongkat Ali as a substance with positive effects on testosterone concentration based on a single available study, while additional studies subsequently identified have indicated that it appears to increase testosterone levels. A study in 109 men with erectile dysfunction and low testosterone showed significant improvements after 12 weeks. According to one review, Tongkat Ali is among the five substances with scientific evidence for increasing testosterone levels, alongside Serenoa repens, boron, ashwagandha root, and fenugreek. Overall, the evidence is promising but based on a relatively small number of trials, often with modest sample sizes.

Fenugreek (Trigonella foenum-graecum)

Traditional Use: Trigonella foenum-graecum, commonly known as fenugreek, is used both as a spice and a medicinal herb. It has a long history of use across Indian Ayurvedic, traditional Arabic, and North African medicinal systems for digestive complaints, metabolic disorders, and as a galactagogue; its traditional use as a male aphrodisiac and androgens tonic is well documented in Ayurvedic texts.

Scientific Evidence: Fenugreek, a short-living annual medicinal plant, is often found in men's sexual health supplements. It contains steroidal saponins, which are hormonal precursors involved in the synthesis of estrogen and testosterone. A meta-analysis of four randomised clinical trials concluded that fenugreek extract has a significant effect on total serum testosterone, and results from clinical trials suggest that fenugreek extract supplement has an effect on serum total testosterone levels in male. The proposed mechanism involves inhibition of aromatase and 5α-reductase: fenugreek supplementation was found to increase levels of free testosterone without reduction in total testosterone, in agreement with a study where fenugreek seeds extract supplementation showed an increase in serum testosterone levels in college-aged men, perhaps by acting as an inhibitor of aromatase and 5α-reductase and increasing free testosterone by decreasing the metabolism of serum testosterone. One open-label 12-week study in 50 male volunteers (aged 35–65) using a proprietary protodioscin-enriched fenugreek extract (FurosapTM, 500 mg/day) found that the majority of subjects demonstrated improvements in mental alertness and mood, and that cardiovascular health and libido were significantly improved. It should be noted that this study lacked a placebo control, which significantly limits its interpretability. Controlled trials showing explicit libido effects are fewer than those showing hormonal changes, and overall evidence strength is rated as moderate to preliminary.

Panax Ginseng (Red Ginseng)

Traditional Use: Ginseng is one of the most precious herbs in traditional Chinese medicine. With over 2,000 years of documented use in East Asian pharmacopoeias, it has been employed as a general tonic (qi restorative), adaptogen, and sexual tonic, typically prepared as a decoction or consumed as a tincture or powder from the dried root.

Scientific Evidence: Tribulus terrestris and ginseng were the most investigated supplements in RCTs for erectile dysfunction, with four out of 14 reviewed RCTs investigating ginseng and its extracts. A Cochrane review offered the most rigorous evaluation of ginseng to date but was restricted to a single herb, with clinical benefits deemed only trivial in magnitude and largely derived from Korean populations. The proposed physiological mechanism includes enhancement of nitric oxide synthesis, facilitating vasodilation in penile tissue. Studies examining ginseng's effect on testosterone concentrations have produced mixed results, and the evidence for a direct effect on libido as distinct from erectile function is not well established in large-scale human trials.

Horny Goat Weed (Epimedium spp.)

Traditional Use: Epimedium species (known as Yin Yang Huo in Traditional Chinese Medicine) have been used for over 1,000 years in East Asian medicine as a kidney-tonifying and yang-invigorating herb, and as an aphrodisiac. Preparations typically involved decoctions or wine infusions of the dried aerial parts.

Scientific Evidence: The primary active constituent is icariin, a flavonoid glycoside that has been studied in preclinical (in vitro and animal) models as a phosphodiesterase-5 (PDE5) inhibitor — the same enzyme targeted by pharmaceutical agents used for erectile dysfunction. According to one analysis, horny goat weed was among the ingredients of popular testosterone-booster supplements, but was categorised as having no evidence of any positive effects on testosterone levels. The clinical evidence base in humans is extremely limited; the majority of mechanistic evidence is derived from in vitro and animal studies, and robust human RCTs are lacking. It is therefore not possible to characterise the evidence as more than preliminary.

Dietary and Lifestyle Factors

Overall Dietary Pattern

The high fibre content of the Mediterranean diet, along with omega-3 fatty acids and antioxidants from foods like olive oil, legumes, whole grains, fruits, and vegetables, plays a crucial role in reducing the risk factors associated with metabolic syndrome — a condition strongly linked to impaired testosterone and sexual function. Dietary patterns that promote cardiovascular health and insulin sensitivity appear to positively support hormonal milieu relevant to male sexual vitality.

Physical Activity and Exercise

A meta-analysis of available trials on the effect of dieting or performing physical exercise on testosterone levels reported that these lifestyle measures were associated with an overall 2–3 nmol/L increase in testosterone levels. Exercise, fitness, and proper nutrition can improve vascular health and reverse or control the factors that contribute to erectile dysfunction. Men who exercise vigorously for 20 to 30 minutes per day are said to be less likely to have erection problems than inactive men. However, excessive or extreme endurance training can have suppressive effects on testosterone, and balance is important.

Body Weight and Adiposity

Excess visceral adipose tissue can disrupt the functioning of hormonal axes by increasing aromatase activity, which converts testosterone to oestradiol, thereby reducing circulating androgen levels. Weight loss in obese men can partially or fully restore suppressed testosterone in cases of functional hypogonadotropic hypogonadism, as obesity-associated low testosterone often improves after weight reduction.

Sleep

Sleep is considered a "third pillar of health" along with diet and exercise. With an understanding of common sleep disorders and how they can impact male sexual function, sleep disorders should be considered as a contributor to sexual dysfunction in clinical evaluation. The majority of daily testosterone secretion occurs in association with sleep, particularly slow-wave sleep; sleep restriction and sleep apnoea have both been associated with testosterone suppression.

Stress and the HPA Axis

Testosterone, synthesized mainly by Leydig cells in the testes, is responsible for the development of sexual characteristics, libido, spermatogenesis, and maintenance of muscle mass, among other functions. Cortisol, secreted by the adrenal cortex in response to activation of the hypothalamic–pituitary–adrenal axis, regulates the body's response to stress, affects glucose and protein metabolism, and has anti-inflammatory and immunosuppressive effects. Both testosterone and cortisol synthesis are subject to circadian rhythms and are sensitive to environmental and behavioural factors. Chronic psychological stress raises cortisol and can reduce GnRH and LH output, functionally suppressing testosterone production.

Alcohol

Evidence from nutritional and endocrinological research consistently indicates that heavy or chronic alcohol consumption negatively affects testosterone biosynthesis at the level of the testes (direct Leydig cell toxicity) and disrupts the hypothalamic–pituitary axis. Professional guidelines emphasise lifestyle-based strategies — such as weight loss, dietary changes, physical activity, sleep interventions, and stress management — as first-line approaches to supporting hormonal health in men.

Multifactorial and Integrated Approaches

Testosterone supplements can have a positive impact on a number of important aspects of men's health, such as vascular endothelial function, mood (particularly in lowering depression), muscle strength, bone health, and sexual function. However, small sample sizes and a dearth of studies limit these findings, highlighting the need for more investigation to completely comprehend the wider impacts of testosterone on men's health. Professional guidelines emphasise lifestyle-based strategies as first-line treatments. No single nutrient or botanical acts in isolation; the interaction of diet, body composition, sleep, stress, psychological wellbeing, and relationship quality collectively determines sexual vitality in men.

Summary of Evidence Strength

• Zinc (in deficient men): Moderate evidence from systematic review that deficiency reduces testosterone and supplementation in deficient populations restores it. Evidence in zinc-sufficient men is weak.
• Vitamin D: Population-level associations exist between deficiency and lower testosterone/erectile dysfunction, but a well-designed RCT found no significant effect of supplementation on testosterone in men with low-normal levels.
• Ashwagandha: Mixed RCT evidence; some proprietary extracts (particularly KSM-66) show statistically significant testosterone increases in specific populations (e.g., infertile men); other extracts and populations show no effect. Evidence is preliminary.
• Maca: Some RCTs show improved sexual desire and subjective erectile function; effects appear independent of testosterone. Evidence is limited and sample sizes small. Overall: preliminary to moderate.
• Fenugreek: Meta-analysis of 4 RCTs supports a significant effect on total testosterone; proposed mechanism involves enzyme inhibition. Evidence is moderate but limited by relatively few high-quality trials.
• Tongkat Ali: Promising signals for testosterone and libido from small trials; evidence from systematic reviews is developing but not yet definitive. Overall: preliminary to moderate.
• Tribulus terrestris: Systematic reviews consistently find low-quality evidence and no robust demonstration of testosterone elevation or libido improvement in humans. Overall: weak.
• Panax Ginseng: Most investigated herbal supplement for erectile function in RCTs; Cochrane review found only trivial clinical benefits. Limited evidence specifically for libido. Overall: weak to preliminary.
• Horny Goat Weed: Mechanistic interest from in vitro/animal work on icariin as a PDE5 inhibitor; human clinical evidence essentially absent. Overall: preclinical only.
• Diet, exercise, sleep, and stress management: Consistent, convergent evidence from multiple study types supporting their role in maintaining testosterone and sexual function. Overall: strongest evidence base in this area.

References

• Impact of Testosterone on Male Health: A Systematic Review — PMC/NIH
• Testosterone therapy improves erectile function and libido in hypogonadal men — PubMed
• Male Sexual Dysfunction — PMC/NIH
• The role of testosterone in male sexual function — PMC/NIH
• Testosterone and Sexual Desire: A Review of the Evidence — Andrology
• Testosterone and sexual function in men — PubMed
• Male sexual dysfunction: pathological mechanisms, risk factors, and herbal drug intervention — ScienceDirect
• Correlation between serum zinc and testosterone: A systematic review — Journal of Trace Elements in Medicine and Biology
• Effects of vitamin D supplementation on androgens in men with low testosterone levels: a randomized controlled trial — PMC/NIH
• Maca (L. meyenii) for improving sexual function: a systematic review — PMC/NIH
• Exploring the chemical and pharmacological variability of Lepidium meyenii: a comprehensive review — PMC/NIH
• Maca (Lepidium meyenii Walp.) on semen quality parameters: a systematic review and meta-analysis — PMC/NIH
• Examining the Effects of Herbs on Testosterone Concentrations in Men: A Systematic Review — PMC/NIH
• Effects of Tribulus (Tribulus terrestris L.) Supplementation on Erectile Dysfunction and Testosterone Levels in Men — PMC/NIH
• Eurycoma longifolia (Jack) Improves Serum Total Testosterone in Men: A Systematic Review and Meta-Analysis — PMC/NIH
• Botanical drugs for treating erectile dysfunction: clinical evidence — PMC/NIH
• Efficacy and safety of eight-week therapy with Ashwagandha root extract in improvement of sexual health in healthy men — PMC/NIH
• Efficacy and safety of ashwagandha root extract on sexual health in healthy men: a prospective, randomized, double-blind, placebo-controlled study — PMC/NIH
• Effects of Ashwagandha on Reproductive Health: A Systematic Review of Sex-Specific Hormonal and Fertility Outcomes — Phytotherapy Research
• Effect of fenugreek extract supplement on testosterone levels in male: A meta-analysis of clinical trials — Phytotherapy Research
• Beneficial effects of fenugreek glycoside supplementation in male subjects during resistance training: A randomized controlled pilot study — PMC/NIH
• Efficacy of FurosapTM, a novel Trigonella foenum-graecum seed extract, in Enhancing Testosterone Level and Improving Sperm Profile in Male Volunteers — PMC/NIH
• Herbal dietary supplements for erectile dysfunction: A systematic review and meta-analysis of randomized-controlled trials — PMC/NIH
• Ginseng and male reproductive function — PMC/NIH
• Influence of Mediterranean Diet on Sexual Function in People with Metabolic Syndrome: A Narrative Review — PMC/NIH
• Effects of Lifestyle, Diet, and Body Composition on Free Testosterone and Cortisol Levels in Young Men — Nutrients (MDPI)
• Understanding the Secular Decline in Testosterone: Mechanisms, Consequences, and Clinical Perspectives — PMC/NIH
• Sleep, Sleep Disorders, and Sexual Dysfunction — World Journal of Men's Health
• Physiology, Testosterone — StatPearls, NCBI Bookshelf
• Integrative Natural Approaches for Age-Related Testosterone Decline — Cureus
• The Psychology of Erectile Dysfunction — Current Directions in Psychological Science
• Impact of Testosterone on Male Health: A Systematic Review — PubMed