Scientifically tested, over-the-counter treatments for thinning hair

Please remember that this information cannot and should not replace the care and advice of a physician. If you experience hair thinning, seek consultation with a medical professional who listens and will physically examine your scalp and assess your overall health. If you take medications on a regular basis, always check for interactions between medications and supplements.

Science-y Hair Blog © 2023 by  Wendy M.S. is licensed under CC BY-NC-ND 4.0 

Be aware that scalps can be sensitive to any and all treatments and products, including natural ones. Scalps that are losing hair may be especially sensitive, proceed with caution.

This post has lots of links. Where I can link you to a full article, I did. Otherwise, I linked to abstracts, which contain a summary of the study's contents. There are some product links on this page for which I may receive a small commission if clicked, at no cost to you, and none of your personal information is available to me.

Updated: June 2024

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Androgenic alopecia is the clinical term of male and female pattern hair loss. It’s one of those diagnoses of exclusion. If you don’t have telogen effluvium (hair loss following an exposure to an allergen, due to physical or mental stressor), or alopecia areata (patches of hair loss), traction alopecia due to tension on your scalp, or hair loss due to thyroid disease, scalp disease or polycystic ovarian syndrome - then you likely have androgenic alopecia.©Science-y Hair Blog 2017

If you start to experience hair loss that is more than you are accustomed to, it’s ideal to have a doctor or dermatologist check for other causes of hair loss before concluding you have androgenic alopecia. Hair loss can be a sign that something else is wrong.

Female pattern hair loss and male pattern hair loss take on different patterns, at the temples, at the crown, both, or the entire front (for men).©Science-y Hair Blog 2017

Androgens are hormones which are more abundant in men than women, specifically testosterone. Testosterone circulates in your blood and in the hair follicle, can be transformed into dihydrotestosterone (DHT) by the enzyme alpha-5 reductase in your hair follicles. This is thought to be damaging to hair follicles. The end result is that hair follicles begin to produce narrow, “vellus” hairs. Like the hairs on non-hairy parts of your body, they are very thin, narrow and difficult to see. As these replace normal-width hairs on your head, the appearance of hair density decreases. 

Note that the "DHT-causes-hair-thinning" idea is not unequivocally proven or the sole cause of hair thinning. There are other variables at work on scalps with thinning hair like low-grade inflammation and atopy (allergy to airborne allergens, contact allergens, yeasts in normal scalp flora).©Science-y Hair Blog 2017

There are some proven treatments for Androgenic alopecia which work in a variety of ways. These are ones you can buy over the counter, they don't require a prescription. Some of them you can use together because different treatments address different causes of hair thinning, such as enzymatic pathways or circulation or inflammation. If in doubt, ask a pharmacist, doctor or dermatologist.

1) Minoxidil (topical). For example: Rogaine. Minoxidil is meant to be applied twice daily as indicated on the label for the optimal adherence to protocol. But if you can't keep that up and want to try it, create a schedule you can manage - because it may still be helpful. Once-daily dosing is recommended for women here. Don't let the twice-per-day thing put you off the treatment.  c

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-Strength: Everybody (women and men) can to use the 5% strength to get the best result, assuming you have no other health problems and are not taking other medications regularly (like blood pressure medication). If you take those medications - please check with your doctor first! 

- It is recommended that women use 5% minodixil only once per day to avoid side effects like facial hair growth.

-Effectiveness: Minoxidil is effective in around 50% to 60% of people who use it. 

- Studies vary, hair count may increase 10% and up to 20-30% with a very good result from Minoxidil. For every 100 hairs, 20-30 more could grow in. As with any product, individual results vary.

- Concentration: Depending on the study, 2% versus 5%: With 5% Minoxidil, results appear more quickly than with 2%. Also, 5% Minoxidil may result in higher hair-counts than 2%, perhaps 5% more (that's 5 hairs per 100). Two percent (2%) Minoxidil can work, and for people who prefer the side effect profile of the lower dose, it's an option.

- How does it work: Minoxidil is a vasodilator, it may encourage growth factors in hair follicles, encouraging cell proliferation, and may inhibit the action of androgens on hair follicles - most of these studies were not done in humans, but in mice, or in extracted cells from human prostate tissue. Do we know exactly how it works? No, but we do know that it does work quite often! 

- Itchy side effects: If you find minoxidil itchy, seek out a propylene-glycol-free formula, or try applying it with a cotton swab.

 - Thrifty/drip-free tip: Apply the product with a cotton swab (drop the product into a little spoon, a plastic cap - don't dip a used swab back in the bottle). That is less likely to leave hair feeling yucky, less likely to drip, and you'll use less product! Make sure you apply enough with a cotton swab that you have a thin coating.

2) Topical caffeine.  It has to go on your scalp, drinking caffeinated beverages doesn’t count. Bummer. 

Caffeine is a quickly-absorbed vasodilator to increase blood flow in the scalp. Caffeine does not need to stay on the scalp until the next washing (that's why shampoos work), but it does need about 2 minutes to absorb into your skin before rinsing 

• In a 2018 study done on men with androgenetic alopecia (in vivo), a 0.2% caffeine solution was used twice per day, increasing the number of hairs in the growing phase (anagen) by almost 11% - similar to the results from 5% Minoxidil used in the same study (yep, that's less than the Minoxidil results above - individual results may vary, the testers were instructed how to use both products). This is equivalent to adding 11 new hairs per 100 hairs already growing on your scalp.

• Topical caffeine affects the whole body and too much on your skin is the same as too much when ingested. If you cannot drink caffeinated beverages - proceed with caution (and/or check with a doctor). Larger concentrations can be dangerous. If you're caffeine-sensitive, topical caffeine might keep you awake if you use caffeine in products at night, or give you a "caffeine buzz" during the day. 

• In lab tests on skin in culture which was treated with testosterone, hair growth was suppressed. When topical caffeine was added, it stimulated hair growth back to normal, so caffeine may counter hair-thinning effects of testosterone in hair follicles.

•  The takeaway message is: Caffeine stimulates hair growth and helps hair stay in anagen phase longer - the growing phase - than it otherwise might in people with androgenic alopecia. Caffeine may slow down excessive shedding and stimulate hair growth. Topical caffeine has been measured to stay active in hair follicles for up to 48 hours, so it needs to be used every 1-2 days to be most effective. Leave-on products and shampoos can both work because caffeine is absorbed into the skin - shampoos need to stay on for 2 minutes.©Science-y Hair Blog 2017

There are a number of products - shampoos, sprays, serums you can purchase which already contain caffeine. Some contain additional ingredients which may be beneficial. There is a do-it-yourself recipe following this list.

Caffeine-Containing Hair Products 

Alpecin C1Caffeine shampoo

Alpecin After Shampoo Liquid 

Amplixin Intensive Hair Growth Serum 

Better Not Younger Fortifying Scalp Serum

ConditionMe Hair Growth Conditioner - Watermans UK brand 

Dove Men + Care Fortifying 2 In 1 Shampoo, Complete 2-in-1 shampoo 

GrowMe Shampoo, Sulfate Free - Watermans UK brand

Just Human Hair Restore Shampoo

Man Cave Caffeine Shampoo 

Marc Anthony Grow Long Shampoo

Plantur 21 Long Hair Shampoo

Plantur 39 Phyto-Caffeine Shampoo for Stressed hair

Revita Hair Stimulating Shampoo  

SebaMed Scalp Activating Shampoo for Thinning Hair 

The Ordinary Multi-Peptide Serum for Hair Density

Thicker Fuller Hair Strengthening Shampoo 

Ultrax Hair Surge Caffeine Hair Growth Stimulating Shampoo 

Ultrax Hair Solaye Conditioner 

Ultrax Labs Hair Plush Thickening treatment serum 

Vegamour GRO Hair Serum

DIY caffeine recipe: 

0.2%, the same as in the study linked above.

Mix the contents of a 200 mg capsule of caffeine powder (such as this one with no fillers or additives) with 100 ml of distilled water (3.3 oz, or just under 1/2 cup)  

Using too much topical caffeine can cause the same side effects as ingesting too much caffeine, or can cause scalp irritation.  Overdosing on caffeine can be very dangerous for people of any age!©Science-y Hair Blog 2017 

I encourage you to consider diluting this to test whether your skin and body tolerates it. If you're not sure this is safe for you, check with a doctor!

The caffeine-water could be mixed with a shampoo (when using, don't dilute a product in its bottle), or made into a spray or put in or in a applicator-tip-bottle to apply to the scalp.

Can brewed tea or coffee be used? Yes. But not decaffeinated tea or coffee. Tea and coffee can create or enhance "cool" or ashy tones in hair. The tea or coffee needs to contact your scalp and be left on for at least 2 minutes. Tea and coffee are complex chemical substances, if you have a very sensitive scalp, it may find these beverages irritating. 

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3) Anti-Dandruff Shampoos

A human trial of 3 anti-dandruff shampoos published in the International Journal of Cosmetic Science in 2002 found the following results (chart below) in 150 men (age 18-65) with mild to moderate hair loss related to androgenetic alopecia, using anti-dandruff shampoos 2-3 times per week after 6 months. The up-arrow means increase, the down-arrow means decrease.

Click to enlarge and make the chart less blurry.

Having 5-8% more hairs in growth phase is good, that means more (normal-sized) hairs are growing. Having reduced shedding is great, it may mean more hairs are staying in anagen (growth) phase. A 10-17% reduction in shedding should be noticeable in the shower or when detangling. Anagen or growth phase can last for several years unless it's shortened by androgenetic alopecia. 

Anti-dandruff shampoos can also decrease oxidative stress and inflammation of the scalp, which is also a component of pattern hair loss - they're anti-oxidants.

The general trends are the important takeaway message. All three ingredients reduced shedding and increased hairs in the growth phase - that means more hairs on the scalp. Ketoconazole and Piroctone olamine may have helped return more vellus hairs to their normal width than Zinc pyrithione. But Zinc pyrithione is a great choice for an effective anti-dandruff and skin-soothing product. Your choice depends on your needs and what works for you.

Anti-dandruff shampoos may not be a "One and Done" treatment for hair loss, but they're potentially supportive of maintaining hair density. They may address the inflammatory aspect of androgenic alopecia.

Products containing these active ingredients can be found on this page, sorted by active ingredient.

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4) Protective foods and nutrients: 

• Higher vanadium intake. Having an adequate intake of vanadium, which is especially high in shellfish, mushrooms, parsley and dill, is correlated with a lower likelihood of having moderate to severe androgenic alopecia, mild androgenic alopecia is still possible. (Abstract link)

• For men - higher soy beverage intake correlated with less severe androgenic alopecia (same reference as above).

• Iron and Vitamin D - you need adequate stores of these. It's best not to supplement without first having a blood test as these very-important nutrients can also cause serious problems if taken when you don't need them. Here is a link to a post with more about these 2 nutrients.

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5) Protective behaviors: Sleep

Sleeping for fewer than 6 hours each night is correlated with more widespread hair thinning in men with androgenic alopecia (in the reference linked in #4). I know, you don’t need to hear that, busy people and night owls. Basic self-maintenance is boring, but it's so important.  Get 6 to 8 hours of sleep every night!

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6) LED and Low-Level Laser therapy

Look for FDA-cleared devices. That clearance does not guarantee they work, but it does mean they've been subject to regulatory processes: Meaning they're supposed to deliver what they say they do. One benefit to these products is - no residue, less potential for contact dermatitis or systemic side-effects. These are not cheap. Assuming they last many years, they can be competitive (price-wise) with some topical products over the same number of years. Light therapy can be easily combined with other sorts of treatments (shampoos, topical treatments). The downside is that you have to commit to using it and be consistent. 

Skin responds to different wavelengths of light. You know that - it's why you wear sunscreen - right?  Some wavelengths promote healing and reduce inflammation. "Healing" is a complicated process, it involves both inflammatory and anti-inflammatory sequences, increased blood supply, and proliferation of growth hormones - among other things. Do you know anybody (men in particular) who had knee-replacement surgery? Ask them if it made their leg a lot hairier! And then stop them before they tell you too much...

Red light and laser therapy may reverse miniaturization of hair follicles - which is part of the androgenetic alopecia process.

Active wavelengths appear to be right around 650-655 nm (can include 630 and 660). A 2021 study indicates that laser therapy at 830 nm (and 785) stimulated hair growth best (though it is an animal study). Stay tuned. By the way - "nm" is nanometer.

Results vary with the product and study. 

• Combining lasers and LED at 655 nm wavelength, One study tallied an up to 35% increase in hair density. It appears that this substantial benefit may have been at the edge of very low-density hair, where the exposure to light is greater. The "best case scenario" may be for the most aggressively thinning areas.

• A product using wavelengths of 630, 650 and 660 (up to 780 nm)had a modest, but significant increase in hair diameter which is meaningful because part of the process of androgenic alopecia is that normal-diameter hairs become "miniaturized" and very narrow.

• Mostly every-other day treatment is recommended. 

• Lasers or LEDs?  Lasers are used in the studies I've seen a brand-name attached to (except for one). Lasers or a combination of lasers and LEDs might be a better investment than a product that uses only LEDs.

• Response rate?  Most studies have been small, few have more than 100 participants. In those studies, 80% or greater of participants had some improvement in hair density. That number was closer to 90% when participants use combination therapy (using either Minoxidil or Finasteride in addition to the light therapy).

• Safe and equally effective for deeper skin tones (Fitzpatrick phototype 4, 5 and 6)? Little testing has been done on deeper skin tones because for clinical tests, tattooing borders has been preferred for hair-counts, which is difficult to see on deeper skin tones. We're getting there, stay tuned. The ways studies are designed and (especially) funded didn't favor inclusivity. I can't explain it for them. No reason that couldn't have been written into the funding. Sure, it's another variable and it might make data analysis more complicated, but what the heck do we spend all those years studying for? To answer simple questions? Hmm? They could have had 2 publications out of that too. Just sayin'.

• Photobiomodulation (LED) therapy does work on deep skin tones for improving even-ness of skin tone and other cosmetic effects. Anecdotally laser and LED lights between 600-700 nm can be effective for hair growth - you can find reviews on product and distributor websites with photos if you like testimonials. LED therapy does not penetrate the skin as deeply. LED light therapy is used to treat Melasma (skin-darkening), it's not likely to cause it if you follow the product instructions. 

• Darker skin absorbs light of different wavelengths differently than lighter skin. Laser therapy (used for hair loss) is in the near-infrared spectrum. It penetrates into deeper layers of skin than LED. Darker skin may absorb more heat from that near-infrared, though it may take longer to accumulate enough light. We don't have great "dosing" information - such as - should one use a longer treatment-time for darker skin? Or will the heat then become a problem? Does darker skin need a different wavelength in order to achieve the correct treatment-depth (when using laser therapy)? More to come in a future (2024-25) post that I'll link here when it's up.

Brands with clinically-tested benefits: This means I can find a published study that reports the results of recommended use on real people with hair loss.

• HairMax Laser Comb (Lower cost, hands-on treatment. It's used like a comb - but can be used to target problem areas too). (Reference)

• iGrow Hair Laser System

• Capillus Hat system - sports-cap style, demonstrated effective in women as well as men (women may have longer hair - that was the issue that needed to be addressed).

• iRestore Hair Growth System - helmet-type model.

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7) Red Clover extract with Acetyl Tetrapeptide-3 (topical)

This ingredient has been shown to inhibit the alpha-5-reductase enzyme, encourage collagen production in the hair follicle (which may stimulate hair growth - this is not entirely clear), and inhibit some pro-inflammatory compounds in the skin. After 4 months of treatment, in a small (14-person treated, 15 placebo) study, the treated group had significantly (statistically significant = unlikely to be due to chance) more hairs in anagen phase - new hair growth - than the untreated group. 13% more hairs in anagen phase than the untreated group. There was also a reduction in hairs in telogen -getting ready to fall out- phase - was about 30% fewer than the untreated group. That means a net gain in hairs both growing in new, and staying on the scalp longer before falling out. This study was published in the Journal of Cosmetic Science . For people with male/female pattern hair loss, that means hairs stay growing for a "normal" life span rather than a shortened life span typical of pattern hair loss. Bear in mind - this is a very small test group!

In a study published in 2020, using both male and female subjects, Red Clover and Acetyl Tetrapeptide-3 and Panax ginseng extract were similar to 3% Minoxidil. Which is not full-over-the-counter-strength. There was an anti-inflammatory effect. Hairs in anagen phase were increased by 13%.

The treatment was left on, and based on the molecular weights of the active ingredients, a leave-on treatment may be more effective than a shampoo.

You can find these ingredients in:

• Alterna Caviar Anti-Aging Clinical Densifying Leave-in Scalp Treatment

• Amplixin Shampoo

• Amplixin Conditioner

• Amplixin Intensive Hair Growth Serum

• Strong Hairpro Deep Scalp Hair Therapy

• Shea Moisture Jamacian Black Castor Oil Strengthen and Restore Shampoo (only red clover extract)

• The Ordinary Multi-Peptide Serum for Hair Density

• Vegamour GRO Hair Serum (No acetyl tetra peptide)

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8) Melatonin (topical)

One study of topical melatonin in androgenic alopecia found that both men and women, treated with a 0.0033% melatonin solution (with other ingredients) experiences a reduction in hair loss of up to 60%. Seborrheic dermatitis was also improved, when it was present. Melatonin may work through an anti-oxidant effect on a scalp experiencing oxidative stress. ©Science-y Hair Blog 2017 

Any formulation containing melatonin may or may not work - most formulas contain multiple ingredients (like biotin or menthol) which have their own functions, confounding the result. The molecular weight of melatonin is small enough to penetrate skin, which is promising. It's also lipophilic, which might give it an affinity for oils on your scalp, or else make it better delivered in a product with an oil (or oil-like) component.

Products for the scalp containing melatonin include NutraM. (Click here for Amazon), "nFuse Night Cap" is another option, as is Zero Mino (with multiple active ingredients).

Melatonin products are applied to the scalp daily, or taking 1 or 2 days off per week. 

Because we have melatonin receptors in our skin, you may experience some sensations of sleepiness or dizziness after applying such a product, just like melatonin supplements. People who have asthma are cautioned to avoid melatonin, and probably need to avoid topical melatonin too. Use with caution! 

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9) Pumpkin-seed containing dietary supplement (with several other active ingredients) 

A pumpkin seed-containing supplement in one, 6-month study which was double-blinded and placebo-controlled (the gold standard for studies such as this) had a positive effect on hair re-growth in men with mild to moderate androgenic alopecia. That translates into 40% increases in hair counts in men treated with this supplement after 24 weeks versus only 10% increases in hair counts for men in the placebo group. [Let's say the net effect was a 30% increase in hair, meaning for every 100 hairs, there were 30 more following treatment.]

You're going to see this taken out of context all over the internet, because the results in the small study were impressive. Don't fall for it. It was a herbal supplement. It contained multiple active ingredients - as stated on the label. Did it contain anything that wasn't on the label? Be skeptical. 

The specific supplement used in this study was “Octo-Sabal Plus” which is not available in the U.S., containing : Octacosanol, Pumpkin seed powder, Mixed vegetable powder, Evening primrose powder, Corn silk extracted powder, Red clover powder, Tomato powder. These are not inactive ingredients, they have systemic actions - and they are probably synergistic, working together to have the end effect.

• Red clover extract is a phytoestrogen (plant estrogen), corn silk extract contains plant sterols which may help with glucose metabolism. Phytoestrogens from plants may modify the onset of androgenic alopecia by reducing inflammation around hair follicles.
• Octocosanol may have mild anti-inflammatory effects and/or improve lipid metabolism (cholesterol, for example). 
• Tomato powder may reduce inflammation and improve lipid metabolism.
• Pumpkin seed extract may interact with alpha 5 reductase and aromatase, which may have an impact in how alpha 5 reductase affects hair follicles.

Pumpkin seed oil may also support nitric oxide formation, an effect which may be supportive of healthy skin barrier function. 

This is a very interesting result, but it's difficult to point to one particular ingredient as the "active ingredient." It's probably more appropriate to say supplement addressed a variety of health conditions that may have working together in these men to contribute to hair loss. 4 capsules were taken each day - which is a lot of supplement.

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10) Various Essential oils (weak evidence)

10 a) In one study, 44% of participants treated with a blend of essential oils (thyme, lavender, rosemary, cedar) in a carrier oil blend -compared to only 6% of the group who used the carrier oils without the essential oils - experienced improvement in return of hair with this particular form of hair loss. The study is linked here and they provide their formula (Scroll down to "Materials and Methods). This was alopecia areata, which is different from male/female pattern hair loss, it is an inflammatory condition.

These essential oils have anti-inflammatory, anti-microbial effects and can promote healing in skin. The oil was applied to the scalp at night (every night), massaged for 2 minutes, then wrapped with a warm towel. No mention is made of whether the scalp/hair was washed in the morning.

This was done nightly for 3-7 months.

This formula is not without risks. Essential oils, even diluted, can cause scalp irritation (which can provoke hair loss - ironically). People with seborrheic dermatitis or very sensitive skin may react badly to the application of oils to the scalp, or may be sensitive to the essential oils. Think: Blisters, swelling eyes, rash. The fragrance of this blend is very strong!

10 b) 3% Peppermint oil alone produced (in mice) a better result in a leave-on solution than 3% Minoxidil (which is not full-strength) for inducing hairs in the growth (anagen) phase and increasing follicle number. Results were visible at 4 weeks in shaved mice. This is not an in-human study, mouse-results may not be the same as human results.

10 c) Rosemary oil proved to be as effective as 2% Minoxidil (pdf link) (which is not full-strength Minoxidil) at increasing hair count by 6 months in human males. The rosemary oil was part of a scalp lotion at 0.37% concentration. The result was tipped more in favor of a decrease in hair loss, which was mild-to moderate for approximately 90% of participants by 6 months. Increase in hair count was mild in 38% of participants.

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How to choose a product?

• Consult with your doctor or dermatologist about what kind of hair loss you have. Don't waste time and money treating the wrong problem.

• Are you taking blood pressure medication, or have a heart or vascular condition? Unless your doctor says it's okay - no Minoxidil for you. But consider topical caffeine products if you can safely consume caffeine, at-home LED/laser therapy, Zinc pyrithione, Piroctone olamine or Ketoconazole shampoo, or enjoy shampoos with essential oils (if they don't irritate your skin). 

• Pregnant? Ask your doctor! 

• Easily irritated scalp or seborrheic or atopic dermatitis (eczema)? Is your skin irritable as a rule? Consider a Zinc pyrithione, Piroctone olamine or Ketoconazole shampoo, in addition to anything else you choose. LED/laser therapy may be a good option as well.

• Need the best-researched return on investment? Minoxidil.