Hair Growth and Hair Fall Ingredient Checker

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. This checker covers topicals, and if you’re looking at devices instead, I’ve reviewed the CurrentBody LED hair growth helmet.

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. Capilia Longa (turmeric stem cells, listed as Curcuma Longa Callus Conditioned Media) joins them, because its placebo results come from the supplier’s own unpublished studies. 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, and it can show up on labels as pyrrolidinyl diaminopyrimidine oxide). Panthenol and salicylic acid are here too, from one small placebo-controlled shampoo trial where they were always mixed together with niacinamide. Black seed oil (nigella sativa) is here as well, from a tiny placebo-controlled pilot in 20 people with sudden shedding. Fluridil (one small trial in men) and bimatoprost (the Latisse lash drug, with barely any published scalp data) are here too. So are thyme and cedarwood oils and garlic, but their trials were in alopecia areata, the patchy autoimmune kind of hair loss, not thinning. Kao’s t-flavanone (one company-funded trial in men), carpronium chloride (a Japanese hair tonic its own guidelines call unproven) and CBD (a case series with no comparison group) are early too, as are L-carnitine (one small brand-run pilot) and Swertia (a tiny 1988 study). 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, bhringraj (Eclipta alba) and amla, the two Ayurvedic hair oil favourites, are here (amla did help women as a syrup they drank, it just hasn’t been tested alone on the scalp). Hibiscus is here too, and its animal results even disagree: leaf extract helped hair grow in rats, but one study found the flower extract slowed it down. Ginger is the odd one out: it’s sold for hair loss, but in the lab its main active slowed hair growth, so its note says so. He shou wu (fo-ti), grape seed extract, menthol (the tingle in scalp shampoos), olive leaf extract, guava leaf (the guava leaf water trend), Sophora flavescens, ginkgo, hinokitiol, emu oil, Platycladus, nettle, mulberry root, fenugreek, licorice, Ecklonia cava seaweed, jujube oil, sage, sulforaphane (broccoli sprout), bee venom, taurine, other seaweed extracts, cinchona (quinine bark), mustard seed, Dictamnus, heartleaf, Korean angelica and quercetin sit here as well, with only mouse and lab dish results. Aloe vera, jojoba oil, horsetail, chebe powder, tocotrienol and spermidine (both only tested as oral supplements) and ruxolitinib cream (which did no better than a plain cream in its trial) go in “No good evidence”, because nobody has shown they grow hair at all. 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). So is batana oil, the TikTok favourite, which has never had a published clinical trial on hair. 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. Niacinamide lands here too. It shows up in plenty of thickening products, but Procter and Gamble’s own scientists reviewed the evidence and concluded it doesn’t stimulate hair growth.

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.

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.