Do Hair Growth Supplements Work?

Do hair growth supplements work? Yes, but not all supplements have the same evidence behind them, and whether they help depends partly on what is causing the hair loss in the first place.

Some hair loss supplements have improved shedding, hair count, or density in human studies, but the evidence isn't equally strong for every product. A few supplements have been tested as complete formulas. In contrast, many others are marketed using research on individual ingredients such as saw palmetto or pumpkin seed oil, even when the finished product itself has never been studied.

For men experiencing thinning or male pattern baldness, supplements cannot be expected to produce the same results as established hair loss treatments like finasteride and minoxidil.

This article looks at which hair growth supplements have the strongest human evidence, how they compare, what results are realistic, how long they may take to work, and how to choose the best hair loss supplement for your routine.

Do Hair Growth Supplements Actually Work?

Yes, some can. But the current evidence applies to specific supplements and ingredients, not to hair growth supplements as a whole.

A 2023 systematic review looked at 30 studies of nutritional treatments for hair loss. Most importantly, the people included did not have a known nutritional deficiency. When the researchers rated the quality of the studies, several branded supplements, including Viviscal, Nutrafol, and Nourkrin, had stronger supporting evidence. Certain individual ingredients, including pumpkin seed oil and tocotrienols, also produced positive results.

The review suggests some supplements may improve hair-loss outcomes even when they aren't simply correcting a vitamin or mineral deficiency. However, the results were tied to specific products, formulations, and ingredients, not hair loss supplements in general.

What Results Can Hair Supplements Realistically Produce?

The most realistic results are reduced shedding, modest gains in hair count or density, and fuller or thicker-looking hair. Supplements may also help when a nutritional problem or another temporary trigger is contributing to diffuse shedding, where hair falls more evenly across the scalp rather than from one specific area.

Hair loss supplements for men are much less likely to restore an area that has been completely bald for years.

Which Hair Growth Supplements Have the Best Evidence?

Viviscal and Nutrafol have some of the best evidence among hair growth supplements. Pumpkin seed oil and saw palmetto also stand out because studies have tested them directly in men with male pattern hair loss (also called androgenetic alopecia). The evidence for biotin and collagen is weak, particularly when they are used on their own.

Multi-Ingredient Nutraceuticals and Marine Complexes

Viviscal Man has been tested in 60 men with clinically diagnosed male pattern hair loss. The men took either Viviscal or an inactive placebo for six months, allowing the researchers to compare what changed with and without the supplement. By the end of the study, the Viviscal group had improvements in total hair count, overall hair density, and terminal-hair density. Terminal hairs are the thicker, pigmented hairs that provide most of the scalp's visible coverage.

Fewer hairs were also removed during a standardized hair-pull test, suggesting reduced shedding.

Viviscal is based on a marine complex formula and contains several active ingredients, so the study cannot tell us whether its marine complex, biotin, zinc, or another component produced the improvement.

Nutrafol Men has also been tested specifically in men with thinning hair. After six months, 79% of men taking Nutrafol rated their hair growth and quality as improved, compared with 51% in the placebo group. The men themselves also reported more improvement, including a greater likelihood of saying the treatment had helped slow their hair loss.

It is important to note that both trials support the formulas, not their ingredients individually. Also, both studies were funded directly by the manufacturers (Lifes2good for Viviscal and Nutraceutical Wellness for Nutrafol), with the company employees even being co-authors. While both studies are placebo-controlled, which is a solid standard, the company's involvement creates a conflict of interest.

Pumpkin Seed Oil

Pumpkin seed oil has been studied directly in men with male pattern hair loss. In a 24-week trial, 76 men with mild-to-moderate androgenetic alopecia took either 400 mg of pumpkin seed oil daily or placebo.

The researchers counted scalp hairs, measured hair thickness, and took consistent "before and after" scalp photos under the same lighting and angle. The photos were reviewed by an investigator who did not know which treatment each man had received.

After 24 weeks, mean hair count had increased by about 40% in the pumpkin seed oil group, compared with about 10% in the placebo group. Men taking pumpkin seed oil also rated their improvement and satisfaction more highly than those taking placebo.

The study did not say whether lower doses or different pumpkin seed oil formulations will produce the same result.

Saw Palmetto

Saw palmetto is often compared with finasteride because both are thought to influence the biological process that drives male pattern hair loss.

In a two-year study of 100 men with male pattern baldness, 38% of those taking saw palmetto showed improvement compared with 68% of those taking finasteride. The researchers also found a difference in where the treatments appeared to work. Finasteride produced improvement in both the frontal scalp and crown, while the response to saw palmetto was mainly concentrated around the crown.

Saw palmetto may have some evidence for hair growth, but the results do not support treating it as an interchangeable replacement for finasteride.

Biotin and Collagen

Biotin is much more popular as a hair growth supplement than the evidence for routine use would suggest.

A 2017 review found 18 published cases in which biotin supplementation improved hair or nail problems. However, every person who improved had an underlying condition associated with poor hair or nail growth.

A 2024 review found surprisingly little research testing biotin on its own for hair growth. Only three human studies met the reviewers' criteria, and none provided convincing evidence that biotin improves hair growth in people taking it as a general hair supplement.

Collagen is harder to judge as a standalone supplement because most positive studies combine it with other ingredients.

In a 12-week study of 83 people with pattern hair loss or chronic telogen effluvium, a form of persistent excessive shedding, 26 of whom were men, participants either continued their condition-specific treatment alone or added a supplement containing hydrolyzed fish collagen, amino acids, iron, and selenium. By week 12, 50% of those taking the supplement showed enough improvement in their scalp photographs to meet the study's improvement criteria, compared with 23% of those continuing treatment without the supplement. Because several ingredients were added at once, the result cannot be attributed to collagen specifically.

Another 12-week study tested a collagen and vitamin C supplement. Expert ratings of healthy hair appearance improved by about 32%, while the measured increase in hair count was not statistically significant. In other words, the hair looked healthier, but the study did not convincingly show that more hair had grown.

For now, the evidence better supports collagen-containing formulas improving how hair looks than collagen alone increasing hair growth.

Can Hair Growth Supplements Treat Male Pattern Baldness?

Some supplements can improve hair-growth measures in men with androgenetic alopecia, but the evidence is weaker and less consistent than it is for finasteride and minoxidil.

Male pattern baldness develops when genetically susceptible follicles respond to dihydrotestosterone (DHT) and gradually miniaturize. Miniaturization means the follicles produce progressively finer and shorter hairs over repeated hair growth cycles. A general multivitamin or botanical blend does not necessarily address DHT-driven follicle miniaturization.

Supplements may instead be used alongside treatments such as finasteride or minoxidil, in the same way that microneedling is used as an adjunct by minoxidil users.

A 2025 study included 225 people with pattern hair loss, 165 of whom were men. Participants received drug treatment alone, or drug treatment plus AGA-P, a supplement containing saw palmetto, pumpkin seed extract, L-cystine and vitamin C. The drug treatments consisted mainly of topical minoxidil and oral finasteride.

After six months, 36.5% of the supplement-plus-treatment group were rated as showing "great improvement," compared with 25% of the drug-treatment-only group.

The results suggest that some hair growth supplements may improve results when used alongside established treatments for male pattern baldness.

How to Choose a Hair Growth Supplement for Men

The best hair growth supplements for men are not the products with the longest labels. Here's how to choose the right one for you.

Match the Product to the Research

Before buying a hair growth supplement, check whether the exact formula or ingredient has been studied in humans. When reviewing the research, look at who took part, what type of hair loss or thinning they had, and how the researchers measured improvement. Did they count hairs, track shedding, rely on photographs and participant ratings, or use methods dermatologists use to measure changes in hair density and thickness?

Also compare the dose on the label with the dose used in the study. A trial using 400 mg of an ingredient does not automatically support a blend containing an undisclosed amount of the same ingredient.

What to Look for on a Hair Growth Supplement Label

Start by checking whether the label tells you how much of each active ingredient the supplement contains. The U.S. Food & Drug Administration (FDA) explains that it does not approve dietary supplements for safety or effectiveness before they are marketed, and proprietary blends may list only the total amount of the blend rather than the dose of each ingredient.

A brand might, for example, promote pumpkin seed oil because it has been studied for hair growth, while never revealing how much pumpkin seed oil its own formula contains. Without that information, you cannot tell whether the product provides anything close to the dose used in the research.

Check the ingredient list for allergens, particularly with marine-derived products. If you take medication, check separately whether any of the supplement's ingredients could interact with it.

Other red flags include promises to regrow completely bald areas, claims that one product works for every type of hair loss, undisclosed ingredient doses, or phrases such as "clinically proven ingredients" when the finished supplement itself has never been clinically tested.

How Long Do Hair Growth Supplements Take to Work?

Most studies that report a benefit assess results after roughly four to six months. A few weeks is often too soon to judge because hair grows slowly and follows a growth cycle that takes months to complete.

The best way to know whether a supplement is working is to compare your hair over time. Take photos before you start, then repeat them monthly using similar lighting, angles, and styling. A consistent hair-tracking method makes small changes much easier to see.

Try not to rely on daily mirror checks. Gradual changes can be hard to notice if you look every day, and different lighting or styling can easily change how your hair looks.

If you use AI-assisted hair tracking, the same principle applies: compare the same areas consistently over time rather than judging your progress from individual photos.

References

• Drake, L., Reyes-Hadsall, S., Martinez, J., Heinrich, C., Huang, K., & Mostaghimi, A. (2022). Evaluation of the safety and effectiveness of nutritional supplements for treating hair loss. JAMA Dermatology, 159(1), 79. https://doi.org/10.1001/jamadermatol.2022.4867
• Ablon, G. (2016). A 6-month, randomized, double-blind, placebo-controlled study evaluating the ability of a marine complex supplement to promote hair growth in men with thinning hair. Journal of Cosmetic Dermatology, 15(4), 358-366. https://doi.org/10.1111/jocd.12265
• Bhatia, N., Ablon, G., Farris, P. K., Hazan, A., & Raymond, I. (2025). A randomized, Double-Blind, Placebo-Controlled study to evaluate the safety and efficacy of a nutraceutical supplement with standardized botanicals in males with thinning hair. Journal of Cosmetic Dermatology, 24(1), e16778. https://doi.org/10.1111/jocd.16778
• Cho, Y. H., Lee, S. Y., Jeong, D. W., Choi, E. J., Kim, Y. J., Lee, J. G., Yi, Y. H., & Cha, H. S. (2014). Effect of Pumpkin Seed Oil on Hair Growth in Men with Androgenetic Alopecia: A Randomized, Double-Blind, Placebo-Controlled Trial. Evidence-based Complementary and Alternative Medicine, 2014(1), 549721. https://doi.org/10.1155/2014/549721
• Rossi, A., Mari, E., Scarnò, M., Garelli, V., Maxia, C., Scali, E., Iorio, A., & Carlesimo, M. (2012). Comparative Effectiveness of Finasteride vs Serenoa repens in Male Androgenetic Alopecia: A Two-Year Study. International Journal of Immunopathology and Pharmacology, 25(4), 1167-1173. https://doi.org/10.1177/039463201202500435
• Patel, D. P., Swink, S. M., & Castelo-Soccio, L. (2017). A review of the use of biotin for hair loss. Skin Appendage Disorders, 3(3), 166-169. https://doi.org/10.1159/000462981
• Biotin for hair loss: Teasing out the evidence. (2024, August 1). PubMed. https://pubmed.ncbi.nlm.nih.gov/39148962/
• Milani, M., Colombo, F., & Group, G. I. (2023). Efficacy and tolerability of an oral supplement containing amino acids, iron, selenium, and marine hydrolyzed collagen in subjects with hair loss (androgenetic alopecia, AGA or FAGA or telogen effluvium). A prospective, randomized, 3-month, controlled, assessor-blinded study. Skin Research and Technology, 29(6), e13381. https://doi.org/10.1111/srt.13381
• Reilly, D. M., Kynaston, L., Naseem, S., Proudman, E., & Laceby, D. (2024). A Clinical Trial Shows Improvement in Skin Collagen, Hydration, Elasticity, Wrinkles, Scalp, and Hair Condition following 12-Week Oral Intake of a Supplement Containing Hydrolyzed Collagen. Dermatology Research and Practice, 2024(1), 8752787. https://doi.org/10.1155/2024/8752787
• Milani, M., Alfano, S., & Group, A. R. S. (2025). Impact of a novel dietary supplement on efficacy of pharmacological treatments for androgenic alopecia: A Real-Life, multicenter, randomized, Assessor-Blinded trial on 225 subjects. Journal of Cosmetic Dermatology, 24(9), e70388. https://doi.org/10.1111/jocd.70388
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