The best hair growth serum for hereditary thinning is 5% minoxidil, sold as Men’s and Women’s Rogaine foam, because it is the only active on this list with FDA approval to regrow hair. If you want a drug-free cosmetic instead, choose one that prints its percentages, such as The Inkey List‘s 1% caffeine plus 1% Redensyl.
Under FDA rules, a product that claims to regrow hair is a drug. That is why the Rogaine carton says “regrow” while cosmetic serums stick to “fuller-looking” and “reduces shedding”.
This ranking sorts seven formulas by what you can check on the label: the named active, and whether the maker says how much of it is in the bottle. Influencer before-and-afters count for nothing here.
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7 hair growth serums ranked by active and concentration
| Formula | Named active | Amount on label | Evidence type | Size | Maker list price |
|---|---|---|---|---|---|
| 1. Men’s Rogaine 5% Foam | Minoxidil | 5% w/w | OTC drug; label cites a 4-month study in men 18 to 49 | 1- or 3-month supply | Not listed |
| 2. Women’s Rogaine 5% Foam | Minoxidil | 5% w/w | OTC drug; once a day | 2- or 4-month supply | Not listed |
| 3. Men’s Rogaine Extra Strength 5% Solution | Minoxidil | 5% w/v | OTC drug; 1 mL twice a day in an alcohol and propylene glycol base | 1- or 3-month supply | Not listed |
| 4. The Inkey List Caffeine Stimulating Scalp Treatment | Caffeine, Redensyl | 1% + 1% | Cosmetic; no product study on the maker page | 150 ml | $17.00 |
| 5. The Ordinary Multi-Peptide Serum for Hair Density | Redensyl, Procapil, Capixyl, Baicapil, AnaGain, caffeine | Not stated | Cosmetic; maker test claims, such as scalp hydration +111% | 60 ml | $24.00 |
| 6. Nutrafol Hair Serum | Ashwagandha exosomes, Irish moss peptides, pea sprout extract | Not stated | Cosmetic; maker cites a clinical study of 34 women | 1 oz | $49.00 |
| 7. Vegamour GRO Hair Serum | Caffeine, turmeric callus media, clover and mung bean sprout extract, peptides | Not stated | Cosmetic; 120-day consumer perception study, 40 people | 30 ml (1-month supply) | $64.00 |
List prices from each maker’s site, checked October 2026. Rogaine’s site links to retailers instead of showing a price. Vegamour’s 30 ml size is from its Amazon listing. Amazon prices change daily; the buttons show today’s price.
Formula: days per bottle = ml / (ml per use x uses per day); a month counts as 30 days. Assumes a full dropper holds about 1 ml, which fits Vegamour selling 30 ml as a 1-month supply and Nutrafol saying a 1 oz bottle lasts about a month on the whole scalp.
Do hair growth serums actually work?
Minoxidil does, for hereditary thinning on the crown, and the cosmetic serums rest on much thinner evidence.
The Men’s Rogaine foam label cites a clinical study of men aged 18 to 49 who used it for 4 months. It says results may show at 2 months with twice-daily use, and to stop and ask a doctor if nothing regrows by month 4.
The cosmetics publish weaker proof. Vegamour’s 93% figure is how 40 people rated their own shedding over 120 days, and The Ordinary’s headline test result is a 111% jump in scalp hydration, which says nothing about hair count.
If your scalp is flaky or oily rather than thinning, a growth serum is the wrong tool. Our guide to the best scalp serum sorts those formulas by scalp problem.
Video: Dr Adel
Hair growth serum vs minoxidil: which should you start with?
Start with 5% minoxidil if thinning runs in your family and shows at the crown or part. Pick a cosmetic serum if you want a drug-free routine and can live with evidence the maker ran itself.
Foam or liquid matters more than most people expect. The Men’s Rogaine solution label lists alcohol and propylene glycol as its base, while both foams leave propylene glycol out, which helps if liquids sting your scalp.
The Drug Facts also rule some people out. The men’s foam is not meant for a receding hairline, and both foam labels say not to use it if your loss is sudden or patchy, or if thinning does not run in your family.
Oils are a third route with their own thin record. Our look at hair growth oil for men covers which oils have any trial behind them.
Which hair growth serum is best for women?
Women’s Rogaine 5% foam, once a day, is the evidence pick. Nutrafol’s serum is the drug-free pick with a study run in women.
The women’s label says results may show at 3 months and to stop if nothing regrows in 6. It also warns that minoxidil may be harmful during pregnancy or breastfeeding, so check with your doctor first if that applies to you.
Nutrafol cites a clinical study of 34 women aged 34 to 55 for its 90-day claims. Vegamour sells GRO to women and men alike, and our Vegamour review covers the rest of its line, including the shampoo and gummies.
How do you read a serum label for concentration?
Look for a percentage next to the active. If there is none, the maker is not telling you the dose.
The Inkey List prints 1% caffeine and 1% Redensyl on its product page. The Ordinary, Nutrafol and Vegamour name their actives but leave out amounts.
US labeling rules list ingredients above 1% in descending order, so actives near the end may sit at 1% or less. On Vegamour GRO, caffeine comes sixth, after water, butylene glycol, glycerin, denatured alcohol and polyglyceryl-10 laurate.
Questions people ask about best hair growth serum
How long does a hair growth serum take to work?
Rogaine's labels say results may show at 2 months for men using foam twice daily and 3 months for women using it once daily. Nutrafol quotes 90 days, and The Inkey List says to give its treatment 3 months or more.
Is The Ordinary hair serum as good as minoxidil?
No trial compares the two. The Ordinary is a cosmetic that names five peptide complexes without stating amounts, while 5% minoxidil is an FDA-approved drug whose label states the study behind it.
Do you have to use minoxidil forever?
To keep the result, yes. Both Rogaine foam labels say continued use is needed to keep your regrowth, and that hair loss will begin again once you stop applying it.
How much does a hair growth serum cost per month?
At list price, Vegamour GRO is $64 for a 1-month supply. The Ordinary is $24 for 60 ml, which lasts longer at a few drops a night. Use the calculator above with your own dose.
