The best shampoo for hair loss, ranked by the evidence

The best shampoo for hair loss is one with ketoconazole, an antifungal with more hair studies behind it than any other shampoo ingredient. Even so, no shampoo is FDA-approved to regrow hair, and the best a shampoo can do is support a treatment that is, such as minoxidil or, for men, finasteride.

That matters because the shampoo aisle is full of hair growth claims. Below, the common ingredients are ranked by the quality of their evidence, with what each study actually measured, followed by what to use alongside them.

Hair loss shampoo ingredients, ranked by evidence

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Why shampoo alone rarely regrows hair

Three things stack up against a shampoo.

Contact time. You lather for a minute or two and rinse. The treatments with the strongest evidence either stay on the scalp all day (minoxidil solution and foam) or work from inside the body (finasteride tablets). Even the ketoconazole label, for its approved use, asks you to leave the lather on for 5 minutes before rinsing.

The law. Under 21 CFR 310.527, the FDA found that over-the-counter hair grower and hair loss prevention claims were “false, misleading, or unsupported by scientific data.” Since the rule took effect in 1990, any over-the-counter product sold to grow hair or prevent hair loss is treated as a new drug that needs FDA approval. The rule names biotin and all other B vitamins, amino acids, jojoba oil and wheat germ oil among the ingredients that lacked evidence. A shampoo can still clean, thicken or condition hair; it just can’t lawfully promise regrowth without approval.

Scalp health is not hair growth. A flaky, inflamed scalp can make hair look worse, which is partly why ketoconazole and pyrithione zinc were tried at all. In finasteride’s trials, every man, on the drug or placebo, used the same medicated tar shampoo for the first 2 years so that seborrheic dermatitis would not confound the hair counts, according to the Propecia label. Clearing dandruff helps the scalp; it is not the same as reversing pattern hair loss.

Ketoconazole shampoo for hair loss

Ketoconazole is an antifungal that acts on the scalp’s yeast, Malassezia, and has some anti-inflammatory activity, which is why researchers tried it on pattern hair loss. It comes in two strengths:

• 2% shampoo (prescription). Its label covers tinea versicolor, a yeast infection of the skin. Use for hair loss is off-label.
• 1% shampoo (over the counter). The Nizoral 1% label covers flaking, scaling and itching from dandruff, used every 3 to 4 days for up to 8 weeks, then as needed.

The hair evidence is small but consistent. In a 1998 study, 2% ketoconazole shampoo improved hair density, hair size and the share of follicles in the growing phase almost as much as 2% minoxidil, and the authors said larger controlled trials were needed. A 2020 systematic review found 5 human studies with 318 participants in total; they reported thicker hair shafts, and the reviewers called ketoconazole a promising add-on or alternative while asking for randomized trials. In 2025, an 11-physician Canadian consensus panel reviewed 45 hair loss interventions and recommended ketoconazole shampoo with near consensus.

Side effects. In 11 double-blind trials of the 2% shampoo in 264 people with dandruff or seborrheic dermatitis, irritation and an increase in normal hair shedding occurred in under 1%. Reports since approval include hair discoloration, abnormal hair texture, loss of curl in permed hair, itching, contact dermatitis, hair loss, and severe allergic reactions including anaphylaxis. Stop and contact a clinician if you get a rash, swelling or trouble breathing.

Cost. Some online hair loss providers add 2% ketoconazole to a finasteride or minoxidil plan. As of October 2026, Strut Health lists it from $25 a bottle and Keeps at $33 per delivery ($23.10 on the first order), shipped every 3, 6 or 12 months. See the ketoconazole shampoo page for the full label summary.

Pyrithione zinc

Pyrithione zinc is the active ingredient in many everyday dandruff shampoos. In a 6-month trial of 200 men aged 18 to 49, a 1% pyrithione zinc shampoo used daily raised total hair counts more than a placebo shampoo from week 9, and the gain held through week 26. The increase was slightly less than half of what 5% minoxidil solution produced, and using both together gave no extra benefit over minoxidil. The men themselves did not clearly see the shampoo’s effect; the improvement tended to show only in the investigator’s assessment.

Caffeine shampoo

Caffeine does reach the follicle: in a 2007 penetration study, caffeine from a shampoo left on for 2 minutes was absorbed through the hair follicles. Whether that changes hair growth is less clear.

• In women with pattern hair loss, a 6-month trial found a phyto-caffeine shampoo reduced the hairs pulled out in a standard pull test by 3.1, against 0.5 with a control shampoo.
• In a 24-week placebo-controlled trial of 154 men, a shampoo with caffeine and dimethylglycine sodium cut hairs pulled by 2.8, against a rise of 0.6 on placebo. Three of the authors are employees of two German companies, Dr. Kurt Wolff and Dr. August Wolff.

Both trials measured shedding, not new hair, and the 2025 Canadian panel listed caffeine among the interventions it did not recommend. A leave-on caffeine liquid has stronger data than a rinse-off shampoo: in an open-label trial of 210 men, a 0.2% caffeine liquid improved the share of growing hairs by 10.59% against 11.68% for 5% minoxidil.

Saw palmetto

Saw palmetto is a plant extract said to block the enzyme that makes DHT, the hormone behind pattern hair loss. The topical evidence is a 24-week study of 50 men using saw palmetto products, with no placebo group; hair counts rose against each man’s own starting point. Taken by mouth, saw palmetto 320 mg a day improved hair in 38% of men over 2 years against 68% on finasteride 1 mg, in an open-label study of 100 men. Our saw palmetto guide covers it in more detail.

Biotin, rosemary and the rest

Biotin is in many “thickening” shampoos, but the FDA’s 1989 rule names biotin among the ingredients without evidence as a hair grower. A 2017 review found 18 reported cases where biotin helped hair or nails, every one in a person with an underlying deficiency or condition, and no good evidence for healthy people. The 2025 Canadian panel did not recommend rosemary oil, piroctone olamine shampoo or leave-on, topical herbal formulations, or shampoos and lotions with fermented papaya and mangosteen.

Hair loss shampoo for women

Women have the same shampoo options and even less shampoo research. The caffeine trial above is one of the few in women. For regrowth, the Women’s Rogaine 5% foam is labeled as a hair regrowth treatment for women, used as half a capful once a day, and the label says continued use is needed to keep the regrowth. Our minoxidil for women guide covers the trials and timelines, and the best hair loss treatments for women list compares providers that treat women.

What to pair with a shampoo

If you are losing hair in a pattern, a shampoo is a supporting act. The approved options are:

• Topical minoxidil, sold without a prescription as a 2% or 5% solution or 5% foam, left on the scalp. See minoxidil for men and how long minoxidil takes to work.
• Finasteride 1 mg tablets, for men only. The label says daily use for 3 months or more is usually needed before a benefit shows. Compare prices on our cheapest finasteride list.

A clinician can also check for causes a shampoo won’t fix, such as sudden or patchy shedding. More options are on our hair loss hub, and the online hair loss providers list compares the services that prescribe them.

The bottom line

No shampoo is approved to regrow hair, and FDA rules treat any over-the-counter regrowth claim as a drug claim that needs approval. Among shampoo ingredients, ketoconazole has the most support, from small studies and a 2025 expert panel, followed by pyrithione zinc and then caffeine, which so far reduces shedding rather than proving regrowth. Use a ketoconazole shampoo if you like, but pair it with minoxidil or, for men, finasteride if you want hair back.