Paste an ingredient list into the box below and pick what you’re worried about. Regrowth is for thinning that’s crept up over time (pattern hair loss). Shedding is for hair fall, when more than usual is coming out in the shower or on your brush. The checker reads every ingredient and grades the ones with any hair research behind them, from strong evidence all the way down to none.
I’ve worn toppers and wigs for over twenty years and written a lot about hair loss on here. Most of what’s on a “growth” label has very little behind it. So every grade links to the study or review it comes from, and you can check my working instead of taking my word for it.
Got seb derm or dandruff? The Seb derm scalp button takes your list over to my skin checker and checks it for malassezia triggers and the antifungals that help.
How the checker grades each ingredient
Every ingredient the checker knows gets one of five grades.
Strong evidence
Minoxidil and finasteride get this one. The NHS lists them as the main treatments for pattern hair loss. Minoxidil can be used by women as well as men. Finasteride tablets are for men only, though some dermatologists prescribe the scalp spray to women who can’t get pregnant (it did about as well as minoxidil in a 2025 trial in women), and a finasteride scalp spray did about as well as the tablets in a 458-man trial. Both only work for as long as you keep using them, and neither works for everyone.
Some evidence
At least one human trial showed a result, but there’s a catch. Usually the trial was small, or the company that sells the ingredient helped run it. Ketoconazole, zinc pyrithione, piroctone olamine, rosemary oil, caffeine, adenosine, stemoxydine, cetirizine, DMG-Na (sodium dimethylglycinate), ashwagandha, pumpkin seed oil, topical dutasteride (a prescription medicine, tested in men only) and the niacin derivatives (octyl and myristyl nicotinate) sit here in regrowth mode, and aminexil and Sandalore (a sandalwood scent tested in 60 women with sudden shedding) join them in shedding mode. The niacin ones are worth a look if you’re a woman, because their trial was one of the few done only in women. Cetirizine (yes, the hay fever tablet) has one of those too. In 66 women, adding a cetirizine lotion to minoxidil thickened hair more than minoxidil with a dummy lotion. In shedding mode, ketoconazole, zinc pyrithione and piroctone olamine also have a 150-man trial where all three shampoos cut hair fall in men with dandruff. Piroctone olamine has a trial in women too, where a shampoo and a leave-on both kept more hair than placebo versions. Caffeine has one too: a caffeine shampoo cut hair fall in women with pattern hair loss over 6 months. Read the reason under each result for what the catch is.
Early or brand-run
Tiny studies, or testing done mostly by the brand. This is where the branded complexes go: Redensyl, Capixyl, Procapil, Baicapil and AnaGain. So do saw palmetto, onion, coffee extract, melatonin (one small trial in 40 women with mixed results) latanoprost (one pilot study in 16 men) procyanidin B-2 from apple (two small trials in 29 men, run by the company behind it) clascoterone (big trials in men have finished, but the results aren’t published yet), exosomes (one pilot study in 20 men, given in a clinic), watercress extract (one study in men, run by the company that makes it), rice bran extract (mostly lab and animal research), peppermint oil (one small human trial with mixed results), lavender oil (only tested mixed with rosemary), ginseng (only tested in a blend with the Capixyl ingredients), copper peptide (one small trial in men, paired with another ingredient), tretinoin (a small, old study, best known for helping minoxidil work), alfatradiol (better at slowing loss than regrowing hair), spironolactone lotion (the tablets have far more evidence) and nanoxidil (small, uncontrolled studies). A 2025 review of these trendy actives found most were tested in blends and small groups, and some of the studies had conflicts of interest.
Lab or animal only
These have only been tested on mice or on hair follicles kept alive in a lab dish. Green tea and bhringraj (Eclipta alba, the Ayurvedic hair oil favourite) are here. Peppermint oil, lavender oil, ginseng and copper peptide used to be too, until each got one small human trial, so they’ve moved up to Early. Loads of things work on mice and then don’t on people, so this grade means “interesting, not proven” (I’d love to see someone run a real trial on them).
No good evidence
People swear by these, but the research doesn’t back them for growth. Castor oil, argan oil and coconut oil are here (coconut oil did help brittle hair in the research). Rice water is here too. It can make hair feel smoother, but there’s little evidence it does anything for growth. Biotin is here too, because it only helped people who were low in it to start with, and thats from taking it as a supplement.
You won’t find a “causes hair loss” list on here. I looked for shampoo and serum ingredients with good evidence that they make hair fall out, and couldn’t find any solid enough to flag (sulfates and silicones included). If your scalp flakes or itches though, that side of things is covered by the Seb derm scalp button.
Shampoo or leave-on?
It also looks for cleansing ingredients like sodium laureth sulfate or cocamidopropyl betaine. If it finds them, it tells you the product looks like a shampoo. Most of these studies used a lotion or serum that stays on the scalp all day. A shampoo is gone in a couple of minutes, so the same ingredient won’t do as much in a wash. Ketoconazole, zinc pyrithione and piroctone olamine are the exceptions, since their trials used shampoo.
Hair growth ingredients: quick answers
Does minoxidil work?
For a lot of people, yes. It’s one of the two main treatments the NHS lists for pattern hair loss, and the only one of the two that women can use. It stops working when you stop using it, and I’ve written about why your hair can keep falling out after you stop minoxidil if that’s where you are right now.
Does rosemary oil help hair growth?
Maybe. The whole rosemary buzz comes from one 2015 trial in 100 men, where rosemary oil did about as well as 2% minoxidil over six months. That’s encouraging. But it’s one small study with no women in it, and it tested the oil on its own. A drop of extract in a shampoo is a different thing.
Does biotin help hair growth?
Only if you’re low in it. A 2017 review found every case where biotin helped involved someone with an underlying problem, like a deficiency. For everyone else there isn’t good evidence, and a biotin shampoo is even further away from what was studied.
Does caffeine shampoo work?
Caffeine’s best trial used a liquid you leave on the scalp. In it, 210 men did about as well on 0.2% caffeine as on 5% minoxidil after six months. The company behind the product was involved though. For hair fall there’s more: in a 6-month trial in women with pattern hair loss, a caffeine shampoo meant fewer hairs came out in a pull test than a plain shampoo. That shampoo had plant extracts in it too, so it’s not caffeine on its own, but it’s a wash-off product tested in women, which is rare.
Does ketoconazole shampoo help with hair loss?
It might help a bit. A small 1998 study found 2% ketoconazole shampoo improved hair density about as much as 2% minoxidil, and the authors said it needed a bigger trial to be sure. It’s also a seb derm staple, so if your scalp flakes as well it’s worth a look for that alone. My seb derm scalp directory has more on that side.
Aminexil vs minoxidil: what’s the difference?
Aminexil and minoxidil sound alike but they’re sold for different jobs. Minoxidil is a medicine for regrowing hair. Aminexil is a cosmetic ingredient aimed at slowing shedding, and its biggest study had no placebo group and was run with Vichy and L’Oréal researchers. I’ve compared the aminexil serums themselves in my hair fall serums post (including the cheap one with the same active as the expensive one).
Does castor oil help hair grow?
There’s no strong evidence it does. A 2022 review of hair oils found castor oil might add a bit of shine and that was about it. Put it on dry ends if you like how it feels, but don’t expect new hair from it.
Get the best result
Copy the list off the actual box if you can. Retailer pages sometimes show an older formula.
Look at the order too. Ingredients are listed from most to least, so an active right at the end of a long list is usually there in a tiny amount.
If your hair has suddenly started coming out in handfuls, see a GP before you spend money on any of this. The NHS says a lot of hair loss is temporary and grows back once the cause is dealt with, so it’s worth finding out what the cause is. The checker can’t diagnose anything (it just reads labels).
Got seb derm or fungal acne on your scalp too? Run the same list through my fungal acne and seb derm ingredient checker as well.
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Sources the checker is built on
Every grade in the checker comes from one of these. Tap the button to see them all, grouped by topic.
Show all 51 sources
Treatments and anti-dandruff ingredients
- NHS: Hair loss treatments – minoxidil and finasteride as the main treatments for pattern hair loss and when to see a GP
- Piérard-Franchimont C, De Doncker P, Cauwenbergh G, Piérard GE. Ketoconazole shampoo: effect of long-term use in androgenic alopecia. Dermatology, 1998 – 2% ketoconazole shampoo compared with 2% minoxidil
- Berger RS and colleagues. The effects of minoxidil, 1% pyrithione zinc and a combination of both on hair density: a randomized controlled trial. British Journal of Dermatology, 2003 – the 26-week zinc pyrithione shampoo trial in 200 men
- Piérard-Franchimont C and colleagues. Nudging hair shedding by antidandruff shampoos: a comparison of 1% ketoconazole, 1% piroctone olamine and 1% zinc pyrithione formulations. International Journal of Cosmetic Science, 2002 – hair fall in 150 men with dandruff
- Piraccini BM and colleagues. Efficacy and safety of topical finasteride spray solution for male androgenetic alopecia: a phase III, randomized, controlled clinical trial. JEADV, 2022 – the 458-man topical finasteride trial
- Panuganti VK and colleagues. A Randomized, Double-Blind, Placebo and Active Controlled Phase II Study to Evaluate the Safety and Efficacy of Novel Dutasteride Topical Solution (0.01%, 0.02%, and 0.05% w/v) in Male Subjects With Androgenetic Alopecia. Cureus, 2025 – topical dutasteride in 135 men
Regrowth ingredients
- Panahi Y, Taghizadeh M, Marzony ET, Sahebkar A. Rosemary oil vs minoxidil 2% for the treatment of androgenetic alopecia: a randomized comparative trial. Skinmed, 2015 – the rosemary oil trial in 100 men
- Dhurat R and colleagues. 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 Pharmacology and Physiology, 2017 – the caffeine liquid trial in 210 men
- Oura H and colleagues. Adenosine increases anagen hair growth and thick hairs in Japanese women with female pattern hair loss. Journal of Dermatology, 2008 – the adenosine lotion trial in 30 women
- Watanabe Y and colleagues. Topical adenosine increases thick hair ratio in Japanese men with androgenetic alopecia. International Journal of Cosmetic Science, 2015 – the adenosine lotion trial in 102 men
- Adenosine as an Active Ingredient in Topical Preparations Against Hair Loss: A Systematic Review and Meta-Analysis of Published Clinical Trials, 2025 – 7 adenosine trials, regrowth and hair fall
- Evron E, Juhasz M, Babadjouni A, Mesinkovska NA. Natural Hair Supplement: Friend or Foe? Saw Palmetto, a Systematic Review in Alopecia. Skin Appendage Disorders, 2020 – saw palmetto
- Topical Alternatives for Hair Loss: Beyond the Conventional. International Journal of Trichology, 2025 – Redensyl, Procapil, Capixyl, Baicapil, AnaGain, onion juice, coffee extract and pumpkin seed oil
- Draelos ZD and colleagues. A pilot study evaluating the efficacy of topically applied niacin derivatives for treatment of female pattern alopecia. Journal of Cosmetic Dermatology, 2005 – octyl and myristyl nicotinate in 60 women
- Fischer TW and colleagues. Melatonin increases anagen hair rate in women with androgenetic alopecia or diffuse alopecia: results of a pilot randomized controlled trial. British Journal of Dermatology, 2004 – topical melatonin in 40 women
- Blume-Peytavi U and colleagues. A randomized double-blind placebo-controlled pilot study to assess the efficacy of a 24-week topical treatment by latanoprost 0.1% on hair growth and pigmentation in healthy volunteers with androgenetic alopecia. JAAD, 2012 – latanoprost in 16 men
- Chen X, Xiang H, Yang M. Topical cetirizine for treating androgenetic alopecia: a systematic review. Journal of Cosmetic Dermatology, 2022 – cetirizine lotion across three small trials
- Bassiouny EA and colleagues. Comparison between topical cetirizine with minoxidil versus topical placebo with minoxidil in female androgenetic alopecia: a randomized, double-blind, placebo-controlled study. Archives of Dermatological Research, 2023 – cetirizine added to minoxidil in 66 women
- Kamimura A, Takahashi T, Watanabe Y. Investigation of topical application of procyanidin B-2 from apple to identify its potential use as a hair growing agent. Phytomedicine, 2000 – the 6-month procyanidin B-2 trial in 29 men
- Takahashi T and colleagues. The first clinical trial of topical application of procyanidin B-2 to investigate its potential as a hair growing agent. Phytotherapy Research, 2001 – the 4-month procyanidin B-2 trial
- ClinicalTrials.gov NCT05910450. A Study to Evaluate the Efficacy and Safety of Clascoterone Solution in Treatment of Male Pattern Hair Loss. Cassiopea SpA – clascoterone, completed trial
- ClinicalTrials.gov NCT05914805. A Study to Evaluate the Efficacy and Safety of Clascoterone Solution in Treatment of Male Pattern Hair Loss (SCALP2). Cassiopea SpA – clascoterone, second completed trial
- Mihaly J and colleagues. N,N-dimethylglycine sodium salt prevents human dermal papilla senescence and promotes hair growth in patients with pattern hair loss. Journal of Dermatological Science, 2026 – DMG-Na in men and women
- Celleno L and colleagues. A Novel Approach Against Male Pattern Hair Loss With Topical Dimethylglycine Sodium Salt (DMG-Na) and Caffeine: Efficacy of a 24-Week, Double-Blind, Randomized, Placebo-Controlled Trial. Journal of Cosmetic Dermatology, 2025 – DMG-Na and caffeine shampoo in 154 men
- Yerram C, Jillella A, Reddy V. Effects of Withania somnifera root extract serum application on hair health in healthy adults: A prospective, double-blind, randomized, parallel, placebo-controlled study. Journal of Ayurveda and Integrative Medicine, 2023 – ashwagandha
- Amini F and colleagues. A Pilot Randomized Controlled Trial (RCT) Evaluating the Efficacy of an Exosome-Containing Plant Extract Formulation for Treating Male Alopecia. Life, 2025 – exosomes
- Ibrahim IM and colleagues. Pumpkin seed oil vs. minoxidil 5% topical foam for the treatment of female pattern hair loss: A randomized comparative trial. Journal of Cosmetic Dermatology, 2021 – pumpkin seed oil in 60 women
- Hashimoto M and colleagues. Effects of watercress extract fraction on R-spondin 1-mediated growth of human hair. International Journal of Cosmetic Science, 2022 – watercress extract
- Effect of peppermint oil on hair growth and hair fall reduction in individuals with diffused hair loss: A randomized controlled study. Indian Journal of Integrative Medicine – peppermint oil on people
- Rosmagain as a Natural Therapeutic for Hair Regrowth and Scalp Health: A Double-Blind, Randomized, Three-Armed, Placebo-Controlled Clinical Trial. Cureus, 2025 – lavender oil mixed with rosemary oil
- An Herbal Extract Combination (Biochanin A, Acetyl tetrapeptide-3, and Ginseng Extracts) versus 3% Minoxidil Solution for the Treatment of Androgenetic Alopecia: A 24-week, Prospective, Randomized, Triple-blind, Controlled Trial (PubMed) – ginseng in a blend on the scalp
- Lee WJ and colleagues. Efficacy of a Complex of 5-Aminolevulinic Acid and Glycyl-Histidyl-Lysine Peptide on Hair Growth. Annals of Dermatology, 2016 – copper peptide (GHK) on people
- Bazzano GS, Terezakis N, Galen W. Topical tretinoin for hair growth promotion. Journal of the American Academy of Dermatology, 1986 – tretinoin, alone and with minoxidil
- The Efficacy and Safety of 17 alpha-Estradiol (Ell-Cranell alpha 0.025%) Solution on Female Pattern Hair Loss: Single Center, Open-Label, Non-Comparative, Phase IV Study. Annals of Dermatology, 2012 – alfatradiol in 53 women
- Clinical and Trichoscopic Evaluations of Topical Finasteride 1%, Topical Spironolactone 5%, and Minoxidil 5% in Female Pattern Hair Loss Treatment. Dermatology Practical and Conceptual, 2025 – spironolactone lotion in women
- Wimpole Clinic: Nanoxidil Guide, Uses, Results and Side Effects (medically reviewed), 2026 – nanoxidil
Shedding ingredients
- Reygagne P and colleagues. An anti-hair loss treatment in the management of mild androgenetic alopecia: results from a large, international observational study. Dermatologic Therapy, 2021 – the 527-person aminexil study
- A combination of pyridine-2,4-dicarboxylic acid diethyl ester and resveratrol stabilizes hypoxia-inducible factor 1-alpha and improves hair density in female volunteers. International Journal of Cosmetic Science, 2020 – the stemoxydine study in 79 women
- Davis MG and colleagues. Scalp application of the antioxidant piroctone olamine reduces hair shedding in an 8-week randomized, double-blind, placebo-controlled clinical study. International Journal of Cosmetic Science, 2021 – piroctone olamine and shedding in women
- Jimenez F and colleagues. Topical odorant application of the specific olfactory receptor OR2AT4 agonist, Sandalore, improves telogen effluvium-associated parameters. Journal of Cosmetic Dermatology, 2021 – Sandalore in 60 women
- Bussoletti C, Tolaini MV, Celleno L. Efficacy of a cosmetic phyto-caffeine shampoo in female androgenetic alopecia. Giornale Italiano di Dermatologia e Venereologia, 2020 – caffeine shampoo and hair fall in women
Lab and animal studies
- Oh JY, Park MA, Kim YC. Peppermint Oil Promotes Hair Growth without Toxic Signs. Toxicological Research, 2014 – peppermint oil in mice
- Lee BH, Lee JS, Kim YC. Hair Growth-Promoting Effects of Lavender Oil in C57BL/6 Mice. Toxicological Research, 2016 – lavender oil in mice
- Pyo HK and colleagues. The effect of tripeptide-copper complex on human hair growth in vitro. Archives of Pharmacal Research, 2007 – copper peptide on hair follicles in the lab
- Choi BY. Hair-Growth Potential of Ginseng and Its Major Metabolites: A Review on Its Molecular Mechanisms. International Journal of Molecular Sciences, 2018 – ginseng
- Kwon OS and colleagues. Human hair growth enhancement in vitro by green tea epigallocatechin-3-gallate (EGCG). Phytomedicine, 2007 – green tea on hair follicles in the lab
- Hair growth promoting activity of Eclipta alba in male albino rats, 2008 (PubMed) – bhringraj in rats
Oils and biotin
- Coconut, Castor, and Argan Oil for Hair in Skin of Color Patients: A Systematic Review. Journal of Drugs in Dermatology, 2022 – castor, argan and coconut oil
- Patel DP, Swink SM, Castelo-Soccio L. A Review of the Use of Biotin for Hair Loss. Skin Appendage Disorders, 2017 – biotin
- A Systematic Review: Application of Rice Products for Hair Growth, 2022 (PubMed) – rice bran extract
- Cleveland Clinic: Rice Water for Hair, Benefits and How to Make – rice water