Hair
Episodes
Derek from More Plates More Dates joins Dr. Rhonda Patrick to discuss testosterone optimization.
In this clip, Drs. Darren Candow and Rhonda Patrick debunk common myths about creatine's effects on hair, sleep, cancer, and urination.
Dr. Rhonda Patrick discusses microdosing nicotine, GlyNac benefits, intermittent fasting and hair loss, and cold & flu relief.
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Derek from More Plates More Dates joins Dr. Rhonda Patrick to discuss testosterone optimization.
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In this clip, Drs. Darren Candow and Rhonda Patrick debunk common myths about creatine's effects on hair, sleep, cancer, and urination.
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Nootropics Omega-3 Fasting Pregnancy Curcumin Sauna Time-Restricted Eating Protein Supplements Urolithin A Rhonda Hair MicroplasticsDr. Rhonda Patrick discusses microdosing nicotine, GlyNac benefits, intermittent fasting and hair loss, and cold & flu relief.
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In this clip, Dr. Rhonda Patrick explores the causes of gray hair, its prevention, and potential remedies like exercise, supplements, and red light therapy.
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As we age, our hair changes: It often turns gray and becomes finer, and it might even fall out—permanently...
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Dr. Rhonda Patrick explores creatine, dairy's effect on polyphenols, eggs' health impact, and new weight loss drugs like Ozempic in her latest Q&A.
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Rhonda Brain Diet Aging Hormones Omega-3 Fasting Memory Testosterone Dementia Development Skin Cocoa HairDr. Rhonda Patrick explores taurine's longevity role, cocoa flavanols, training adaptations, and oral hyaluronic acid in a Q&A.
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Dr. Rhonda Patrick answers audience questions on various health, nutrition, and science topics in this Q&A session.
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Rhonda Vitamin D Microbiome Hormones Omega-3 Melatonin Bone Time-Restricted Eating Cardiovascular Supplements HairDr. Rhonda Patrick answers audience questions on various health, nutrition, and science topics in this Q&A session.
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Dr. Rhonda Patrick answers audience questions on various health, nutrition, and science topics in this Q&A session.
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Rhonda Vitamin D Gut Ketosis Insulin Resistance Fasting Sulforaphane Intestinal Permeability NRF2 Urolithin A HairDr. Rhonda Patrick answers audience questions on various health, nutrition, and science topics in this Q&A session.
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Rhonda Vitamin D Exercise Parkinson's Epigenetics Omega-3 Fasting Melatonin Vaccine Resveratrol Sauna Insulin COVID-19 Cardiovascular Autoimmunity HairDr. Rhonda Patrick answers audience questions on various health, nutrition, and science topics in this Q&A session.
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Rhonda Vitamin D Heart Disease Pregnancy Vaccine Skin Zinc Time-Restricted Eating Blood Sugar COVID-19 Breast Milk HairDr. Rhonda Patrick answers audience questions on various health, nutrition, and science topics in this Q&A session.
Topic Pages
News & Publications
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Many supplements are marketed for hair health, but few have been tested in clinical trials. In a study published in 2007, researchers examined whether supplementing with a bioavailable form of silicon could improve hair quality.
The trial included 48 healthy Caucasian women with fine hair that had not been colored or permed. Participants took two capsules daily for 9 months, providing either 10 milligrams of silicon per day as choline-stabilized orthosilicic acid (ch-OSA) or a placebo. At the start and end of the study, researchers collected hair samples and tested the fibers for elasticity and breaking force, then used microscopy to measure hair-shaft size.
- Hair elasticity declined less with ch-OSA, decreasing by 4.5% compared with 11.9% in the placebo group. The decline in both groups may have reflected differences in when the sampled hair was formed, including seasonal exposure to sunlight, heat, or humidity.
- Hair fibers better maintained their breaking force. The force needed to break a fiber declined by 2.2% with ch-OSA, compared with 10.8% with placebo.
- Hair-shaft size increased. The cross-sectional area increased by about 8% in the ch-OSA group, compared with about 4% in the placebo group.
- The ch-OSA group excreted more silicon in urine, and the rise in silicon excretion was associated with an increase in hair-shaft cross-sectional area. This points to a possible link between silicon availability and hair-shaft structure.
Laboratory studies suggest that the form of silicon used in this study stimulates collagen synthesis in cultured skin cells. Collagen is part of the matrix around the hair follicle, where cells help control hair growth and build each strand. A healthier collagen-rich matrix could give those cells a more stable environment for forming the hair shaft, potentially contributing to a slightly wider strand. Wider strands are generally better able to withstand stretching and breaking.
The main limitations are that the trial was small and industry-funded. With fewer participants, results are more likely to be affected by chance, and industry funding can introduce bias in how the findings are analyzed or interpreted. Nevertheless, the results identify bioavailable silicon supplements as a promising candidate for further study in larger, independent trials. In Aliquot #112, I discuss approaches to reverse hair loss and graying.
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Finasteride is one of the most popular prescription drugs for male hair loss, but questions about its psychiatric safety have lingered for over two decades. A new review analyzed postmarketing data to determine whether the drug contributes to depression, anxiety, or suicidality, and to examine why these risks took so long to be recognized.
The analysis brought together eight independent human studies conducted over the last decade. Four used adverse event reporting systems from agencies such as the U.S. Food and Drug Administration (FDA) and the World Health Organization (WHO), and four used national health records from Canada, Sweden, France, and Israel. The studies addressed finasteride prescribed mainly for androgenetic alopecia, commonly called male pattern baldness.
The results were strikingly consistent across all studies:
- Every study reported higher rates of depression, anxiety, self-harm, or suicide among finasteride users.
- FDA reports showed roughly three to five times more suicidal thoughts and up to nine times more completed suicides among users relative to the combined background reporting for all other medications in the database.
- Global data from the WHO's VigiBase found similar patterns, with up to a four-fold increase in reports of suicidal thinking or psychological distress.
- Large national datasets found that finasteride users had about 20 to 210 percent higher risks of depression or self-harm; an increased risk of completed suicide was detected only in the French study, and only in people with pre-existing mood disorders.
- Despite these signals, underreporting was severe. In a population of about 4.6 million finasteride users, the FDA received only 18 suicide reports by 2011 and 320 by 2024, compared with thousands that would be expected based on general population rates.
Finasteride blocks an enzyme called 5-alpha-reductase, which is needed to produce neurosteroids such as allopregnanolone that help regulate mood and stress. Reduced levels of these brain chemicals can alter nerve growth, inflammation, and gene activity, potentially leading to long-lasting depression and anxiety, even after the drug is stopped.
These findings reflect both a genuine safety signal and a systemic failure of drug oversight. Neither the manufacturer nor regulators conducted the necessary analyses when early warning signs appeared in the early 2000s. Depression was added to finasteride's safety label only in 2011, and suicide risk was formally acknowledged by U.S. regulators in 2022 and by the European Medicines Agency in 2025.
Overall, this suggests that finasteride can cause serious and sometimes even persistent psychiatric adverse effects, urging stricter postmarketing surveillance, systematic reporting of medication histories in suicide cases, and a reassessment of the risk-benefit balance for a drug used mainly for cosmetic purposes. Discover other approaches to reverse hair loss and graying in Aliquot #112.
- Every study reported higher rates of depression, anxiety, self-harm, or suicide among finasteride users.
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Hair loss affects self-image and mental well-being, yet evidence on whether diet can prevent or improve it has been inconsistent. To clarify the picture, researchers systematically reviewed human studies examining how individual foods, nutrients, and supplements influence hair health.
They analyzed 17 studies involving over 61,000 participants, mostly women, spanning childhood to older age. Only studies on specific foods or nutrients were included, not whole-diet patterns. The studies examined a range of hair-related conditions, including alopecia areata (a patchy, autoimmune form of hair loss), androgenetic alopecia (commonly known as male or female pattern hair loss), and general hair thinning or shedding.
Several consistent patterns emerged across the evidence:
- Low vitamin D levels correlated with greater severity and longer duration of alopecia areata and with worse premature androgenetic alopecia in men.
- Iron supplementation improved self-reported hair growth in women with low iron status and alopecia.
- Protein deprivation reduced the diameter and pigmentation of hair bulbs, indicating compromised hair quality.
- Higher intake of cruciferous vegetables was linked to less hair loss, with soy intake showing a similar but weaker trend.
- Drinking more than 3.5 liters of sugar-sweetened beverages per week was associated with male pattern hair loss, and alcohol use related to greater hair loss and earlier greying.
- A marine protein supplement reduced hair shedding and promoted growth in women with temporary thinning. Hydrolyzed eggshell membrane increased hair density.
These findings fit plausible mechanisms. Vitamin D helps regulate follicle regeneration through Wnt/β-catenin signaling. Iron supports DNA synthesis in fast-dividing follicle cells. Adequate protein is needed for keratin, the main hair protein. Sugary diets may increase scalp oil and inflammation, while cruciferous vegetables and soy supply antioxidant and anti-inflammatory compounds that can reduce follicle stress.
While the results of the study point to clear dietary signals, most included studies were observational or high-risk clinical trials, and outcome measures varied widely. Explore other evidence-based approaches to reversing hair loss and graying in Aliquot #112.
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Creatine supplementation does not influence hair growth or hormone levels even after three months of usage, undermining theories of its potential link to hair loss. www.tandfonline.com
Concerns about hair loss have long surrounded creatine, one of the most widely used and extensively studied supplements for enhancing muscle strength and lean mass. Although these claims persist, they are primarily based on anecdotal reports and limited evidence. A recent study found no support for the idea that creatine contributes to hair loss.
Researchers administered either 5 grams of creatine monohydrate or a placebo daily for 12 weeks to 45 healthy, resistance-trained men aged 18 to 40. They excluded participants who had used anabolic-androgenic steroids (which can promote hair loss) or other hormonal enhancement agents within the preceding six months. At the beginning and end of the study, researchers measured testosterone levels, free testosterone, and dihydrotestosterone and assessed hair density and growth. The men maintained their regular diets and workout routines throughout the intervention.
The men taking creatine showed no significant changes in hormone levels or hair health compared to those taking the placebo. Both groups experienced a modest increase in total testosterone—about 15%—regardless of which supplement they consumed. Free testosterone dropped slightly in both groups, while levels of dihydrotestosterone and hair growth measurements remained stable.
These findings suggest that creatine does not harm hair follicle health or elevate dihydrotestosterone levels in healthy men, even after three months of use. Learn more about creatine supplementation in this episode featuring Dr. Darren Candow.
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Gray hair is often considered an inevitable part of aging, but evidence suggests lifestyle strategies—including diet—could slow it down. A recent study in mice found that luteolin, a plant-derived antioxidant, may help prevent hair graying by targeting key cellular processes.
Researchers tested the effects of three antioxidants—luteolin, hesperetin, and diosmetin—on hair graying in mice prone to premature graying. They applied the compounds topically and administered them orally, then analyzed changes in hair color, stem cell activity, and molecular markers associated with aging hair follicles.
Luteolin, but not the other antioxidants, substantially reduced hair graying in the mice. Both topical and oral luteolin helped maintain communication between hair follicle stem cells and melanocyte stem cells,which are essential for pigment production. Mice treated with luteolin also had fewer aging-related changes in these cells, suggesting it protects against age-related hair follicle dysfunction.
These findings suggest that luteolin is a promising candidate for an anti-graying treatment. Luteolin is abundant in celery, green pepper, broccoli, carrots, and olive oil, and is also available as a dietary supplement. Learn about other strategies to slow or prevent hair graying in this episode featuring Dr. Rhonda Patrick.
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Cinnamon is one of the most consumed spices in the world, popular in both sweet and savory dishes in many cuisines. Evidence suggests cinnamon improves lipid profiles and protects against damage induced by oxidative stress, improving metabolic profiles in people with type 2 diabetes. New research now shows that a component of cinnamon may promote hair growth.
Researchers studied the effects of cinnamic acid, a component of cinnamon, on hair growth. First, they treated dermal papilla cells (cells involved in hair formation and development) with varying concentrations (0 to 2,000 micrograms per milliliter, µg/mL) of cinnamic acid. They found that low to moderate concentrations of the compound (less than 500 µg/mL) increased the production of genes involved in hair growth and enhanced the activity of receptors for oxytocin, a hormone, in the cells.
Next, they studied the effects of cinnamic acid on hair follicle organoids called follicloids. Organoids are three-dimensional tissue cultures produced from stem cells that mimic the structure and activity of the organ from which they are derived. They applied varying concentrations (0, 50, 100, and 500 µg/mL) of cinnamic acid to the follicloids and measured hair growth for 10 days. They found that concentrations of 100 to 500 µg/mL of cinnamic acid promoted hair growth in the follicloids by the eighth day.
These findings suggest that cinnamic acid is a viable option for promoting hair growth by targeting the oxytocin receptor. Recent research found that oxytocin promotes hair growth, but because oxytocin breaks down rapidly and is a relatively large molecule, it isn’t a good candidate for use in pharmaceutical or cosmetic treatments to grow hair. However, cinnamic acid is a naturally occurring polyphenol with potent antioxidant, anti-inflammatory, and anti-cancer properties. Learn more about polyphenols in our overview article.
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Medications induce gray hair re-pigmentation, pointing to potential future therapies. www.ncbi.nlm.nih.gov
Graying hair is a cardinal sign of aging, typically beginning in a person’s fourth or fifth decade. Nutritional deficiencies, including low intake of protein, vitamin B12, iron, and copper, can contribute to premature graying. However, a recent review found that some medications may promote gray hair re-pigmentation.
Researchers reviewed 27 studies and case reports of medication-induced gray hair re-pigmentation, totaling 133 patients. They categorized the various drugs as anti-inflammatories, stimulators of melanogenesis (the production of melanin, the pigment responsible for hair, skin, and eye color), vitamins, medications that accumulate in tissues, and those with an undetermined mechanism. Then, they ranked the quality of the evidence for each study or report.
They found that medications that reduce inflammation or stimulate melanogenesis can promote diffuse re-pigmentation of gray hair. They also found that vitamin B complex supplementation may contribute to the darkening of gray hair, but they cautioned that evidence supporting this finding was weak.
These findings suggest that certain medications induce gray hair re-pigmentation. Although these drugs aren’t presently recommended for treating gray hair, their mechanisms provide insights into potential targets for future medications aimed at hair re-pigmentation.
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Graying of hair is related to psychological stress but may be reversible. www.scientificamerican.com
The loss of hair pigmentation (graying) is a hallmark of aging. Although it typically begins during a person’s twenties, the timing and extent of graying vary according to genetics and interactions between biological and psychological factors. Graying is generally considered irreversible, but findings from a recent study demonstrate that graying is not necessarily a linear process and may be reversible.
One of the primary drivers of graying is oxidative stress, which damages the pigment-producing region of the hair shaft. Oxidative stress occurs during the process of oxidative phosphorylation (the generation of energy) in mitochondria and can be reflective of exposures to both physical and psychological stressors. Evidence suggests that depigmented hairs may exhibit altered mitochondrial energy metabolism. Interestingly, case and anecdotal reports suggest that hair re-pigmentation can occur, causing bicolor hairs.
The authors of the study collected dark, depigmented, and bicolor hairs from 14 healthy young adults (average age, 35 years) who did not color, bleach, or chemically treat their hair. The authors digitally mapped pigmentation patterns in the hairs over time and assessed protein content in the hair shafts. Some of the participants completed a retrospective stress assessment questionnaire using a life event calendar, in which they recorded major events over a given time. Then the authors overlaid the hair pigmentation patterns on the participants' life events.
The authors found that depigmentation and re-pigmentation events corresponded with specific moments in the participants' lives, with depigmentation linked to stressful events (such as marital discord) and re-pigmentation linked with non-stressful events (such as a vacation). The authors also found that depigmented hairs contained more proteins linked to mitochondrial function and energy use, suggesting that mitochondria and metabolism are involved in the graying process.
These findings suggest that graying of hair is a more malleable process than once thought and indicate that studying changes in hair color may provide insights into how psychological stressors influence health.
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Stress has far-reaching effects on the human body, including increased risk of chronic disease and other conditions associated with aging. Anecdotal reports suggest that stress can contribute to the premature graying of hair. Findings from a recent study in mice suggest that acute stress depletes melanocyte stem cell populations to promote the graying of hair.
Melanocyte stem cells are undifferentiated cells found in the region of hair associated with growth. They give rise to melanocytes, the mature, melanin-forming cells that provide color to growing hair.
Both mental and physical stress activate the body’s sympathetic nervous system, one of the two main divisions of the autonomic nervous system (the other being the parasympathetic nervous system). The sympathetic nervous system’s primary purpose is to stimulate the body’s fight-or-flight response to stress. A critical element in this response is noradrenaline, a type of hormone and neurotransmitter that plays a role in vigilance and conditioned fear.
The authors of the study induced acute stress in mice and noted that the mice exhibited increased numbers of gray hairs. This increased graying was attributed to the activation of sympathetic nerves in the region in which the stem cells reside and subsequent release of noradrenaline, which promoted stem cell proliferation, differentiation, migration, and eventual depletion.
These findings suggest that neuronal activity induced by an acute stressor can drive stem cell loss and illustrate how overall mental and physical health influence stem cell health.
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Hair Regeneration by Small Molecules That Activate Autophagy papers.ssrn.com
Hair plays important roles, ranging from the conservation of body heat to the preservation of psychological well-being. Hair loss or alopecia affects millions worldwide and can occur because of aging, hormonal dysfunction, autoimmunity, or as a side effect of cancer treatment. Methods that can be used to regrow hair are highly sought after, but lacking. Here we report that hair regeneration can be stimulated by small molecules that activate autophagy, including the longevity metabolites α-ketoglutarate and α-ketobutyrate, and the prescription drugs rapamycin and metformin which impinge on TOR and AMPK signaling.
Chai, Min and Jiang, Meisheng and Vergnes, Laurent and Fu, Xudong and de Barros, Stéphanie C. and Jiao, Jing and Herschman, Harvey R. and Crooks, Gay M. and Reue, Karen and Huang, Jing, Hair Regeneration by Small Molecules That Activate Autophagy (2018). Available at SSRN: https://ssrn.com/abstract=3188356 or http://dx.doi.org/10.2139/ssrn.3188356