Hair loss shampoo: what it can do, and what it can't
Two active ingredients have published data, most of the shelf has none. I go through what the studies say about ketoconazole and caffeine, and where the limits of the shampoo format are.
What can a shampoo do at all?
Shampoo spends a few minutes on the scalp, then you wash it out. That's the limit of this format: a cosmetic shampoo doesn't treat the cause of patterned (androgenic) hair loss, DHT, and it doesn't reset the hair cycle either. I've written about the hormonal cause in the DHT blocker article, and about sudden, diffuse shedding in the telogen effluvium article.
What shampoo is for: scalp condition. Dandruff, oily, inflamed scalp is its own territory, and two active ingredients stand out with published data related to hair loss: ketoconazole and caffeine (zinc pyrithione also has a few small trials, but it's been banned in cosmetics in the EU since 2022). The rest of the shampoos on the shelf are typically cosmetics, without a hair-loss trial behind them.
Ketoconazole: the antifungal that hair loss research is also looking at
Ketoconazole is an antifungal active ingredient, used against the Malassezia yeasts that cause dandruff. The hair-loss-oriented interest comes from the fact that it may also reduce the microbe-driven inflammation around the follicle, and the study's authors partly attribute the result below to this. Piérard 1998
The clinical data is thin, but it exists: in a small, old study, hair density and the share of hairs in the growth phase improved "almost similarly" in the group using the 2% ketoconazole shampoo as in the 2% minoxidil group. Piérard 1998 Small sample, old study, not proof on its own. The summary of a 2020 review: ketoconazole is a "promising adjunctive or alternative" option, and randomized controlled trials would be needed. Fields 2020
In most EU countries, the 2% ketoconazole shampoo is a registered medicine, available in pharmacies. medicines database I use a ketoconazole shampoo myself, alongside finasteride and minoxidil, as a supplement to them.
Zinc pyrithione shampoo: what has been measured for hair loss?
Alongside ketoconazole, zinc pyrithione is the other old anti-dandruff active ingredient. Few, small trials have measured it for hair loss, and they show different things. Berger and colleagues also compared it against placebo in 2003: they studied 200 men aged 18 to 49 with moderate-stage (Hamilton–Norwood III vertex or IV type) balding. They were split into four groups for 26 weeks: daily 1% zinc pyrithione shampoo, twice-daily 5% minoxidil solution, placebo shampoo, or the shampoo and minoxidil together. Hair counts were done from microscopic photos, and the assessor didn't know which group each person was in. Berger 2003
From week 9, significantly more hairs were counted in all three treated groups than with placebo. Of the growth measured against placebo, the shampoo brought a bit less than half of what minoxidil brought, and this held roughly steady through week 26. The two together gave no more than minoxidil alone. The authors' summary describes the effect as “modest and sustained”. Berger 2003
In the overall photographic impression, the shampoo alone showed only a trend for the assessor too (P<0.1), and it didn't show in the participants' own rating. The Berger trial's abstract gives the growth only relative to minoxidil, I couldn't access its full text, so I also can't say how many hairs this amounts to. Five of the seven authors were Procter & Gamble employees; the abstract doesn't name the funder. Berger 2003
Piérard-Franchimont and colleagues studied 150 men with dandruff in 2002, whose increased shedding was combined with androgenic hair loss. For six months they used a 1% ketoconazole, 1% piroctone olamine, or 1% zinc pyrithione shampoo 2 to 3 times a week; there was no placebo group, the three shampoos were compared against each other, so it isn't known how much of the change is down to the shampoos. At the end, hair density hadn't changed. The amount of hair shed while washing, assessed by estimation, decreased: by 17.3% with ketoconazole, 16.5% with piroctone olamine, 10.1% with zinc pyrithione. The proportion of growth-phase hairs rose (per the abstract, 4.9% with ketoconazole, 7.9% with piroctone olamine, 6.8% with zinc pyrithione). Average hair thickness rose with the other two, and fell 2.2% with zinc pyrithione. The authors' conclusion was that all three 1% shampoos kept the increased shedding (telogen effluvium) in check. Piérard-Franchimont 2002 A 2021 trial compared a single treatment containing six active ingredients (including zinc pyrithione, shampoo plus a leave-on) against placebo: compared with placebo, less shedding and more hair were measured, its funder was Procter & Gamble, and zinc pyrithione's own effect can't be isolated from this. Davis 2021
In the European Union, zinc pyrithione has been a banned substance in cosmetics since 1 March 2022, so it can't be in drugstore shampoos either. Under the EU regulation, this is because it was classified as a reproductive toxicant (category 1B). The EU's Scientific Committee on Consumer Safety considered it safe up to 1% in rinse-off, anti-dandruff hair products, but the exemption wasn't granted anyway, because it wasn't shown that no suitable alternative active ingredient existed. Regulation (EU) 2021/1902 If you're looking at hair count, the minoxidil effect measured in the Berger trial was larger, and adding the shampoo didn't give more.
Caffeine shampoo: what do the studies say?
According to the current interpretation, caffeine raises the level of an intracellular messenger (cAMP) in the hair follicle Szendzielorz 2025, and in a laboratory study it counteracted the growth-suppressing effect of testosterone. Fischer 2007
The largest single study is about a SOLUTION left on the scalp: in a 6-month study following 210 men, the share of hairs in the growth phase improved by 10.59% with the 0.2% caffeine solution and by 11.68% with 5% minoxidil, and the authors rated the caffeine solution "noninferior". Dhurat 2017 The limitations: open-label design (everyone knew what they were using), and it is a single study.
The 2025 systematic review found 9 clinical studies with a total of 684 participants: the direction is encouraging, but the strength of the evidence is low in most of the studies, and only 4 of the 9 measured caffeine on its own; 5 studies tested multi-ingredient formulations, where the effect cannot be attributed to caffeine alone. Szendzielorz 2025 In another breakdown: 4 of the 9 studies were done with a shampoo and 5 with a leave-on format; the review did not compare the two formats by strength of evidence.
In this study, the caffeine SOLUTION was not inferior to minoxidil (caffeine 10.59%, minoxidil 11.68%). It was a solution left on the scalp, not a shampoo, in an open-label design. Dhurat 2017
The "DHT-blocking shampoo" label
Many shampoos on the shelf carry the label “DHT blocker,” typically with saw palmetto, caffeine or herbal extract. On a cosmetic label this term is a marketing category: a rinse-off cosmetic shampoo doesn't lower the body's DHT level. For curbing the androgenic cause and the prescription route, see the DHT blocker article; for an honest balance on oral natural agents, see the natural DHT blockers article.
Is there a finasteride or minoxidil shampoo?
Abroad, mostly online, products called “finasteride shampoo” are sold. The ones I found that genuinely contain finasteride are prescription, pharmacy-compounded (magistral) products (one American pharmacy, for example, sells a shampoo like this containing finasteride, minoxidil and progesterone); I didn't find an example of a registered finasteride shampoo. Most hair-loss shampoos, though, are made without finasteride, with saw palmetto, caffeine or biotin; the American company Keeps, for example, says on its own page that its “Thickening Shampoo” contains biotin, caffeine, green tea and saw palmetto, and the page itself states that it doesn't treat hair loss. I didn't find a clinical study of a genuine finasteride, minoxidil or dutasteride shampoo. In the registered finasteride spray's study, the product had to be left on the scalp for at least 6–8 hours; a shampoo is in contact for a few minutes, and I didn't find a measurement of how much acts in that time. In the European Union, minoxidil is a prohibited substance in cosmetics. For more on combination products and shampoos: finasteride and minoxidil together.
What a shampoo can't do, and the warning signs
A cosmetic shampoo alone doesn't stop pattern hair loss: the cause is hormonal, and a shampoo is a short-contact, rinse-off form. If a product promises more than that, it's worth asking three questions: who was it tested on, compared to what, and was the result published? The label “clinically tested” alone answers none of these. A specific percentage claim without a published study is a red flag.
If you don't know which type of shedding you have, start here: which pattern is yours?
The gist: shampoo is a supporting format. Ketoconazole and caffeine have published data related to hair loss (zinc pyrithione also has a few small trials, but it's been banned in cosmetics in the EU since 2022); the strength of the evidence is low, and the largest caffeine trial used a leave-on scalp solution, not a shampoo. A cosmetic shampoo doesn't treat the cause of patterned hair loss, that's what the medication route, covered in the minoxidil and DHT articles, is for.
Frequently asked questions
Which is the best shampoo for hair loss?
An honest brand ranking isn't possible: active-ingredient shampoos have rarely been compared with each other, without a placebo, and by active ingredient rather than by brand. What the evidence gives: ketoconazole and caffeine have data related to hair loss (zinc pyrithione also has a few small trials, but it's been banned in cosmetics in the EU since 2022); the rest of the shampoos are scalp care. Instead of asking which is “best”, it's worth checking whether the shampoo you have your eye on contains one of these, and what you expect from it: it can improve scalp condition, but it doesn't treat the cause of the loss on its own.
Do caffeine shampoos actually work?
Caffeine has encouraging clinical data; the largest study was done with a solution left on the scalp. Dhurat 2017 According to the 2025 review, the direction is positive, but the strength of the evidence is low in most of the studies; 4 of the 9 studies used a shampoo and 5 a leave-on format, the two were not compared, and only 4 studies measured caffeine on its own, the rest in mixtures. Szendzielorz 2025 With a rinse-off shampoo, in any case, the contact time is shorter.
Which is the best caffeine shampoo?
There is no published study comparing the brands, and the active ingredient is the same caffeine. What's worth checking: whether caffeine is listed, how much it costs, and whether your scalp tolerates it well. A big-name product isn't better just because it's better known.
What is ketoconazole shampoo for, and do you need a prescription?
It is primarily for treating dandruff and scalp complaints tied to the Malassezia yeast. Its hair-loss-oriented data is adjunctive in nature: in a small study, improvement similar to 2% minoxidil was described alongside it, and the review calls it a promising adjunct. Piérard 1998 Fields 2020 In most EU countries it is a registered medicine, available in pharmacies; the exact usage is given in the patient information leaflet. medicines database
Does zinc pyrithione shampoo help against hair loss?
Few, small trials have measured it. Berger and colleagues counted more hairs against placebo in 200 men in 2003, a bit less than half of minoxidil's effect; the participants themselves didn't see the difference, and five of the seven authors were Procter & Gamble employees. Berger 2003 In a 2002 trial without a placebo, in 150 men with dandruff, hair density didn't change, shedding fell by 10.1%, the proportion of growth-phase hairs rose (6.8%), and hair thickness fell by 2.2%; the authors say it kept the increased shedding in check, but without a placebo it isn't known how much of that is down to the shampoo. Piérard-Franchimont 2002 In the European Union it's been a banned substance in cosmetics since 1 March 2022. Regulation (EU) 2021/1902
Do women and men need different shampoos?
Is there a shampoo for hormonal hair loss?
I didn't find a shampoo that a study showed to treat the hormonal cause. Drugstore shampoos are cosmetics, and they can't claim a therapeutic effect either. Finasteride has been studied left on the scalp for hours via a spray; a shampoo stays on for a few minutes, and I didn't find a measurement of how much acts in that time. The hormonal route, the prescription options, and what comes before medicine: that's what the DHT blocker article is about.
Can a hair loss shampoo be given to a child?
With childhood hair loss, the first step is a doctor: the common causes (fungal infection, patchy hair loss, hair pulling) all call for a diagnosis. Use an active-ingredient shampoo on a child only on medical advice.
Does frequent hair washing cause hair loss?
The vast majority of the hairs you see when washing were already at the end of their resting phase, washing merely dislodges them. Sudden, even shedding typically has a cause months earlier; I wrote about this in the diffuse hair loss article. If the shedding is persistent or patchy, it deserves a medical work-up.
Sources
Every number and claim on this page comes from the sources below. The studies were not done with our products, and they describe group-level results. This is information, not medical advice.
- Piérard-Franchimont C, et al. Ketoconazole shampoo: effect of long-term use in androgenic alopecia. Dermatology. 1998. PMID 9669136 · small, old trial: alongside the 2% ketoconazole shampoo, hair density and the anagen ratio improved “almost similarly” to the 2% minoxidil group; the authors explain it with an anti-scalp-microflora and anti-inflammatory effect.
- Fields JR, et al. Topical ketoconazole for the treatment of androgenetic alopecia: A systematic review. Dermatol Ther. 2020. PMID 31858672 · review; it calls ketoconazole a “promising adjunct or alternative” option, stressing that randomised, controlled trials are needed.
- Dhurat R, et al. An Open-Label Randomized Multicenter Study Assessing the Noninferiority of a Caffeine-Based Topical Liquid 0.2% Versus Minoxidil 5% Solution in Male Androgenetic Alopecia. Skin Pharmacol Physiol. 2017. PMID 29055953 · n=210 men, 6 months: the anagen improvement was 10.59% for the 0.2% caffeine solution and 11.68% for 5% minoxidil; the authors call the caffeine solution “non-inferior”. Open-label, a single trial.
- Szendzielorz E, Spiewak R. Caffeine as an Active Ingredient in Cosmetic Preparations Against Hair Loss: A Systematic Review. Healthcare. 2025. PMID 39997270 · 9 clinical trials, 684 participants in total; the results are encouraging, but the strength of evidence is moderate in 3, low in 1, and very low in 5 trials; of the 9, 4 measured caffeine alone, 5 tested a multi-ingredient product.
- Fischer TW, et al. Effect of caffeine and testosterone on the proliferation of human hair follicles in vitro. Int J Dermatol. 2007. PMID 17214716 · laboratory (in vitro) trial: caffeine counteracted testosterone's growth-inhibiting effect in hair follicle culture.
- NNGYK (Hungarian National Center for Public Health and Pharmacy) drug database: NIZORAL anti-dandruff shampoo 20 mg/g. ogyei.gov.hu/gyogyszeradatbazis · registration number OGYI-T-01828, active ingredient ketoconazole, a valid Hungarian licence (TK).
- Piraccini BM, et al. Efficacy and safety of topical finasteride spray solution for male androgenetic alopecia: a phase III, randomized, controlled clinical trial. J Eur Acad Dermatol Venereol. 2022. PMID 34634163 · the spray had to be left on the scalp for at least 6–8 hours.
- Regulation (EC) No 1223/2009 of the European Parliament and of the Council on cosmetic products, Annex II (substances prohibited in cosmetic products), entry 372: minoxidil. eur-lex.europa.eu
- Keeps: Thickening Shampoo, product page (keeps.com, accessed 26 September 2026) · biotin, caffeine, green tea, saw palmetto; finasteride isn't listed in its description.
- PHC Pharmacy (USA): Finasteride / Minoxidil / Progesterone Shampoo, product page (accessed 26 September 2026) · a prescription, pharmacy-compounded shampoo.
- Berger RS, Fu JL, Smiles KA, Turner CB, Schnell BM, Werchowski KM, Lammers KM. The effects of minoxidil, 1% pyrithione zinc and a combination of both on hair density: a randomized controlled trial. Br J Dermatol. 2003. PMID 12932243 · 200 men, 26 weeks, four groups; the zinc pyrithione shampoo's hair-count growth was “a bit less than half” of the minoxidil solution's. Five of the seven authors were Procter & Gamble employees; the abstract doesn't name the funder.
- Commission Regulation (EU) 2021/1902 of 29 October 2021 amending Annexes II, III and V to Regulation (EC) No 1223/2009. eur-lex.europa.eu · zinc pyrithione has been on the list of substances prohibited in cosmetics since 1 March 2022.
- Davis MG, Piliang MP, Bergfeld WF, et al. Scalp application of antioxidants improves scalp condition and reduces hair shedding in a 24-week randomized, double-blind, placebo-controlled clinical trial. Int J Cosmet Sci. 2021. PMID 34424558 · a six-ingredient shampoo and leave-on treatment (piroctone olamine, zinc pyrithione, zinc carbonate, niacinamide, panthenol, caffeine) against placebo; funder: P&G Beauty. Zinc pyrithione's own effect can't be isolated from this.
- Piérard-Franchimont C, Goffin V, Henry F, Uhoda I, Braham C, Piérard GE. Nudging hair shedding by antidandruff shampoos. A comparison of 1% ketoconazole, 1% piroctone olamine and 1% zinc pyrithione formulations. Int J Cosmet Sci. 2002. PMID 18498517 · 150 men with dandruff, 6 months, three active shampoos compared against each other, no placebo; hair density didn't change, shedding fell by 10.1% with zinc pyrithione, and average hair thickness fell 2.2% with it.