Peptides in Hair Care: What They Do and How to Use Them
Looking for peptide skincare for firmer skin? A pharmacist can advise. This page covers peptides and proteins in shampoos, conditioners and masks.
Peptides in hair care have moved from the small print of skincare labels onto the front of shampoo and conditioner bottles, usually alongside words like strengthening, repairing or bond-building. It is easy to be sceptical. This guide explains what peptides and hydrolysed proteins actually are, what they can realistically do for hair you already have, how to spot them on an ingredients list, who should go easy on them, and how to build them into a routine without overdoing it.
Our hair growth shampoo
Grow Me® Hair Growth Shampoo, £14.95. A sulphate free daily shampoo that supports a healthy scalp environment and helps reduce breakage, so lengths hold on and look fuller.
Peptides in hair care are short chains of amino acids, usually made by breaking down larger proteins such as keratin, wheat, soy or lupine into smaller pieces. In shampoos, conditioners and masks they cling to the hair surface, fill in rough, damaged areas of the cuticle and help strands feel smoother and stronger, which means less breakage when you brush and style. They are cosmetic ingredients that improve the hair fibre, not medicines that change how follicles grow.
Key takeaways
- Peptides are short chains of amino acids; proteins are long chains. Hydrolysis breaks proteins into smaller, more usable pieces.
- A 2015 review in the International Journal of Trichology notes that keratin in hair is heavily cross-linked protein, mostly rich in cystine.
- The same review explains that added amino acids cannot replace or restore the hair's own keratin, so the benefit is a smoother, stronger-feeling surface.
- Low porosity and fine hair can feel stiff with heavy protein use, so match the amount to your hair.
- In Great Britain every cosmetic must have a safety assessment by a qualified assessor before it is sold.
What are peptides and hydrolysed proteins?
Peptides and hydrolysed proteins are fragments of protein. A protein is a long chain of amino acids folded into a shape; a peptide is a short chain, often just a handful of amino acids long. Hydrolysis uses water, enzymes or gentle chemistry to cut large proteins into these smaller pieces, which are easier to dissolve into a formula and small enough to settle onto the hair surface.
Hair itself is made mostly of a protein called keratin. The 2015 review by Gavazzoni Dias in the International Journal of Trichology describes how the cuticle and cortex contain heavily cross-linked protein, mostly rich in the amino acid cystine, arranged in spiral fibres that give hair its strength. When hair is bleached, heat-styled or roughly handled, that structure is damaged, and the surface becomes rough and porous.
That is where protein-based ingredients come in: they are attracted to damaged, porous areas and help fill them in, which is why they appear in so many repairing products.
What can peptides in hair care actually do?
Peptides in hair care can make damaged hair feel smoother, look shinier and resist breakage better, because they coat and fill the rough, porous parts of the hair fibre. The effect builds up with regular use and washes away gradually, so it needs topping up.
It is just as important to be clear about what they cannot do. The review states plainly that keratin is an irreplaceable protein for its mechanical and protective properties and that using amino acids does not replace or restore it. In other words, peptides improve how existing hair behaves, but the hair shaft is not living tissue and cannot rebuild itself. Real repair only comes with new growth from the scalp.
| What peptides can do | What they cannot do |
|---|---|
| Smooth a rough, lifted cuticle so hair feels softer | Rebuild the hair's own internal keratin |
| Reduce snapping during brushing and styling | Change how quickly or thickly hair grows from the follicle |
| Help porous, colour-treated hair hold moisture better | Mend split ends permanently; only a trim does that |
| Add a little body and grip to fine hair | Act as a medicine for any scalp or hair condition |
How do you spot peptides on an ingredients list?
You spot peptides on an ingredients list by looking for the word hydrolyzed (spelled the American way on UK labels, which use international INCI names) followed by a protein source, or for names ending in peptide or tripeptide. Ingredients are listed in descending order of amount, down to 1 per cent.
| Label name | Where it comes from | Typical use |
|---|---|---|
| Hydrolyzed keratin | Animal sources such as wool or feathers | Repairing masks and conditioners for bleached or heat-styled hair |
| Hydrolyzed wheat protein | Wheat | Volumising shampoos and leave-ins for fine hair |
| Hydrolyzed soy or rice protein | Soy beans or rice | Strengthening products; plant-based alternatives to keratin |
| Hydrolyzed lupine protein | Lupin seeds | Shampoos, conditioners and masks for stronger-feeling, fuller-looking hair |
| Copper tripeptide-1 | A lab-made peptide bound to copper | Scalp serums and skincare |
The review notes that keratin hydrolysates are usually prepared from keratin-containing animal parts, such as feathers, horns and wool, while some brands use plant amino acids from wheat, corn and soy to mimic keratin. If you avoid animal-derived ingredients, plant proteins such as lupine, soy or wheat are the ones to look for. Our guide to copper peptides for thinning hair looks at copper tripeptide in more detail.
Which Watermans products contain peptides?
Several Watermans products contain hydrolysed lupine protein, a plant-derived protein ingredient, alongside other conditioning ingredients. They are cosmetic products designed to help hair look and feel thicker and stronger, not medicines.
Grow Me® Hair Growth Shampoo £14.95
A gentle, sulfate-free shampoo with hydrolysed lupine protein, caffeine, biotin, rosemary and niacinamide, for a clean, comfortable scalp and fuller-looking hair. Vegan and made in the UK.
Condition Me® Hair Growth Conditioner £13.95
A breakage-defence conditioner with hydrolysed lupine protein, cholesterol and shea butter to smooth the lengths and help reduce snapping when you detangle.
Get a discount on the hair breakage range
Join the Watermans mailing list and we will email a discount code straight to your inbox, so you can try the hair breakage range for less. Made in the UK, over 6.5 million bottles sold since 2012.
Who should go easy on protein and peptide products?
People with low porosity or very fine hair should go easy on protein and peptide products, because their tight cuticle does not have many damaged areas for protein to fill, so extra protein sits on top and can leave hair feeling stiff, straw-like or brittle. This is often called protein overload.
- Low porosity hair: use protein-rich masks occasionally, not every wash, and follow with a moisturising conditioner.
- High porosity or bleached hair: usually welcomes regular protein because it has more damage to fill.
- Signs of too much: hair that feels rough and squeaky, snaps when stretched or will not hold moisture.
- The fix: switch to a protein-free conditioner for a few washes and let the balance settle.
Not sure which you have? Our guide to hair porosity has a simple at-home check.
Are peptides in hair care safe?
Peptides in hair care are generally well tolerated, and in Great Britain every cosmetic product must be checked for safety by a qualified safety assessor before it can be sold, according to government guidance on cosmetic products. That safety report forms part of the product information file the responsible person must keep.
Any ingredient can still cause a reaction in some people. The NHS explains that contact dermatitis can be caused by substances such as cosmetics, and wheat-derived proteins are worth checking if you have a known wheat allergy. Patch test a new product on a small area first, and stop using anything that stings, itches or makes your scalp red.
Is it breakage, shedding or hair loss?
Protein and peptide products help with hair breakage, but they do nothing for hair shedding or hair loss, because those start at the root in the scalp rather than along the fibre. Knowing which one you have saves money and frustration.
| Problem | What is happening | Will peptide products help? |
|---|---|---|
| Hair breakage | The fibre snaps part-way along, leaving short, uneven pieces and split ends | Yes, they strengthen the surface and reduce snapping |
| Hair shedding | Whole hairs fall from the root, often a few months after illness or stress | No; the NHS says losing 50 to 100 hairs a day is normal |
| Hair loss | Follicles produce finer hairs over time or hair falls in patches | No; see a GP if you are worried |
For what actually damages hair in the first place, see our guide to what causes hair damage. If you are losing hair from the root, in patches or with a sore scalp, the NHS advises seeing a GP. Watermans does not give medical advice. If your question is about products or a routine rather than a medical one, you can talk to Gail Waterman, our co-founder, as an AI avatar on the Watermans homepage.
How do you use peptide products in a routine?
You use peptide products in a routine by letting each one do its own job: a protein-containing shampoo to cleanse, a conditioner on the lengths every wash, and a richer mask once a week if your hair is damaged. Leave masks on for the time stated, rinse well, and judge the results over a few weeks.
- Shampoo the scalp gently and rinse.
- Condition the mid-lengths and ends every wash.
- Mask weekly in place of conditioner if your hair is bleached, coloured or heat-styled.
- Protect with a heat spray before styling, so you are not undoing the work.
Masque Me® Hair Mask £24.95
An 8-in-1 deep-conditioning mask with hydrolysed lupine protein, argan oil and vitamins. Used once a week on the lengths, it helps damaged hair feel softer, smoother and stronger.
What are the frequently asked questions about peptides in hair care?
What do peptides do for hair?
They cling to the surface of damaged hair and fill rough, porous areas, so hair feels smoother and stronger and snaps less when you brush and style.
Are peptides and keratin the same thing?
Keratin is the main protein hair is made of. Hydrolysed keratin is keratin broken into smaller pieces, which are peptides.
Can peptides repair split ends?
They can smooth and hold split ends together temporarily, but only a trim removes them for good.
Can you use too much protein on hair?
Yes. Fine or low porosity hair can feel stiff and brittle with heavy protein use, so balance it with moisturising conditioner.
Are plant peptides as good as keratin?
Plant proteins such as lupine, soy and wheat also coat and smooth hair, and suit anyone who avoids animal-derived ingredients.
Do peptide shampoos make hair grow?
No. Peptides improve the hair fibre you already have; they do not change how follicles grow.
Should I patch test peptide products?
It is sensible with any new product, especially if you have a wheat allergy or sensitive skin.
What is the bottom line on peptides in hair care?
The bottom line on peptides in hair care is that they are useful, well-understood cosmetic ingredients that make damaged hair feel smoother and stronger and help it resist breakage. They coat and fill the hair surface rather than rebuilding it, so they suit bleached, heat-styled and porous hair best and need a lighter touch on fine or low porosity hair. They do nothing for shedding or hair loss from the root, which is a question for your GP.
If breakage is your main concern, a breakage-defence conditioner with hydrolysed lupine protein is the simplest place to start.
Sources & references
- Gavazzoni Dias MF, Hair cosmetics: an overview, International Journal of Trichology, 2015 (PubMed Central), checked 19 September 2026.
- GOV.UK, Making cosmetic products available to consumers in Great Britain, checked 19 September 2026.
- NHS, Contact dermatitis, checked 19 September 2026.
- NHS, Hair loss, checked 19 September 2026.
Watermans products are 100% cosmetic and do not treat medical hair loss. Individual results may vary.
