My hairbrush was starting to look a little too full this past year, so my hairstylist told me to consider investing in one of the best biotin shampoos. Biotin – also known as B7 – is a water-soluble vitamin that plays a key role in supporting healthy hair, skin, and nails. New York City dermatologist Maryam Safaee, MD, says that if you have brittle nails and hair thinning, that could be a sign that you are deficient in the nutrient in biotin. “Biotin (AKA vitamin B7) plays a key role in keratin production, an essential protein in skin and nail health.”

Personally, I only knew about biotin in supplement form, but it’s now showing up in shampoos and scalp treatments designed to strengthen strands and reduce breakage at the root. Unlike supplements that work internally (and can take months to show results), biotin shampoos work topically – cleansing the scalp, reinforcing the hair shaft, and setting the stage for fuller-looking growth. “When applied topically, biotin does offer hydration benefits to the hair and scalp,” says New York City-based dermatologist and cosmetic surgeon Howard Sobel, MD. It’s a great ingredient to incorporate into your routine if you have dry hair, too.

So, who’ll benefit most? If you’re dealing with thinning hair, shedding, or an overall lack of volume, a biotin shampoo could be a game changer.

After researching dozens of formulas and factoring in everything from texture to scent to real-user results, Ouai’s Fine Hair Shampoo came out on top as our best overall pick. It combines biotin with hydrolysed keratin and chia seed extract to plump up limp strands without weighing them down, and leaves hair smelling like you just walked out of a salon. Other options stood out for their ability to repair damaged strands or treat frizz.

The best biotin shampoos, at a glance

Best Overall: Ouai Fine Hair Shampoo

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Ouai Fine Hair Shampoo

• What we love: Delivers noticeable volume, sulphate-free formula is safe for colour-treated hair, salon fragrance
• What could improve: Scent may be overpowering for some, some users without fine hair say it isn’t hydrating enough

Fine hair is notoriously high-maintenance (I’ve dealt with it myself for over three decades). It wants volume, but not too much; moisture, but never grease. Enter Ouai’s Biotin Shampoo, a salon-level formula that strikes just the right balance. “Biotin, hydrolysed keratin, and chia seed oil help coat and smooth the hair shaft, which will provide strength, shine, and a reduction in frizz,” says Dr. Safaee. It lifts at the roots, strengthens mid-lengths, and smells like a chic SoHo blowout you somehow gave yourself.

“This gentle shampoo is one of my favourites because it always does the job of making my fine hair look a lot more voluminous and bouncy. It has a lightweight gel formula that lathers nicely without weighing hair down and it never makes my roots or strands look greasy and flat. Instead they have bouncy body,” says GLAMOUR commerce writer Alanna Martine Kilkeary.

Best for Thinning Hair: Pura D’or Original Gold Label Anti-Thinning Shampoo

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Pura D’or Original Gold Label Anti-Thinning Shampoo

• What we love: Clinically tested to reduce hair thinning and increase volume, sulphate-free and safe for use on colour-treated hair, vegan, cruelty-free
• What could improve: Some with sensitive scalps find the botanicals slightly irritating

Okay, so your hair’s thinning but your patience isn’t. With a blend of 17+ DHT-blocking herbal actives – including nettle, saw palmetto, and pumpkin seed oil – this sulphate-free formula aims to reduce hair thinning due to breakage, increase volume, and strengthen strands. Users have reported less shedding and fuller-looking hair after consistent use.

Best for Colour-Treated Hair: SheaMoisture Strengthen & Restore Shampoo with Jamaican Black Castor Oil

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SheaMoisture Strengthen & Restore Shampoo with Jamaican Black Castor Oil

• What we love: Safe for any chemically treated strands, rich and creamy lather, pleasant and refreshing scent with herbal notes
• What could improve: May be too heavy for fine hair