The 4 best products and how you can get longer, healthier and shinier strands

Collagen has fast become the beauty world’s favourite buzzword. So much so that it’s now the Beyoncé of the supplement aisle, showing up in everything from serums and shampoos that promise to turn back the clock on your skin and scalp. In haircare, more specifically, we’re told it can make our locks thicker and shinier, but knowing that most collagen cannot penetrate the skin, let alone a dead shaft of hair, how much of this glossy trend is actually backed by science?

According to trichologist Hannah Gaboardi, collagen’s connection to healthy hair is somewhat real – just not quite in the way the internet might have you believe. “Collagen is the most abundant protein in your body,” she explains. “It’s a kind of scaffolding that keeps your skin firm, your nails strong, and your hair supported from the roots.”

While it’s not a magic ingredient that winds its way into each strand, collagen does a lot of vital behind-the-scenes work. “It provides strength and elasticity to the skin on your scalp – the environment where your follicles live and grow,” says Hannah. “A healthy scalp means stronger follicles, which can lead to thicker, shinier hair over time.”

In other words, collagen may not be living rent-free in your actual hair, but it’s definitely the quiet landlord keeping the whole building standing.

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The role of collagen in haircare

Many assume collagen is a building block inside the hair itself, but Hannah clarifies that’s not the case. “Collagen does not actually live inside your hair shaft; it’s not part of the hair fibre itself,” she explains. “Instead, it supports hair growth indirectly by maintaining the health of your scalp and the connective tissue around your follicles.”

Studies show collagen strengthens the dermal layer beneath the scalp’s surface (the foundation where hair follicles are anchored). “When that layer weakens, whether through age or nutrient deficiencies, follicles can become less supported, leading to finer strands or increased shedding,” she adds.

And while collagen can’t “fix” damaged hair – since the visible strand is made of keratin and is technically dead tissue – it can still help protect what grows next. “Collagen cannot directly repair damaged hair,” says Hannah, “but by boosting your body’s natural collagen levels through diet or supplements, you help maintain a stronger scalp barrier and support healthier new growth.”

Ageing naturally affects this process too. “From our mid-20s, collagen production drops by about 1 per cent each year,” she explains. “Environmental stress, UV exposure, smoking, and poor diet can speed that up. With less collagen, the scalp loses elasticity and circulation, which affects how nutrients reach your follicles. That’s why hair can start to feel more fragile and less voluminous over time.”

What to look for in a collagen haircare product

When it comes to collagen-infused shampoos and masks, Hannah says the benefits are mostly surface-level. “The collagen molecule is simply too large to penetrate the scalp or hair shaft,” she notes. “Topical collagen can make hair feel softer and smoother, but it can’t reach the follicles where new hair forms.”

In other words, that instant shine is cosmetic. “These products coat the hair cuticle for temporary smoothness and hydration rather than true structural repair,” she says. “They can give your hair a quick boost in texture and gloss, but they don’t rebuild it from within.”

Still, not all formulas are created equal. “Some advanced products combine collagen with amino acids, peptides, or keratin,” Hannah explains. “These can help reinforce the outer cuticle and improve manageability – so while they won’t make your hair grow faster, they can help it look and feel better.”

If you’re scanning ingredient labels, Hannah recommends looking for ‘hydrolysed collagen’, also known as collagen peptides. “This form has been broken down into smaller molecules that are easier for your body to absorb when taken orally,” she says. “For topical products, collagen paired with humectants like hyaluronic acid or glycerin can attract moisture and make hair feel smoother. Just avoid vague claims like ‘marine collagen complex’ without a clear ingredient breakdown.”

And yes, oral collagen does seem to live up to the hype. “There’s growing evidence that collagen supplements can support hair growth, strength, and overall quality,” says Hannah. “When ingested, collagen peptides break down into amino acids such as glycine and proline, which your body uses to build keratin, the main protein in hair.”

“Studies show that after 12 to 16 weeks of consistent use, people often notice thicker strands, less shedding, and improved shine,” she adds. “It’s not a miracle cure, but it’s one of the few wellness trends with genuine science behind it – especially when combined with a balanced diet and good scalp care.”