Do peptides work for skin?
A little, in small, short trials. Two peptides reduced fine lines over 4 to 12 weeks. But both are bigger than skin is thought to let in. One number explains why.
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Do peptides work for skin?
A little, going by a few small trials. A 2017 review found the evidence is often weak, and the prices can be quite high.
Peptides are short chains of the building blocks of protein. Two have the clearest trials. Both did a bit better than a cream without the peptide.
| Peptide (label name) | Trial | What it found |
|---|---|---|
| Palmitoyl pentapeptide-4 (also sold as Matrixyl) | 93 white women aged 35 to 55, for 12 weeks. Run by Procter & Gamble. | Fewer wrinkles and fine lines than the same moisturiser without it. |
| Acetyl hexapeptide-8 (Argireline) | 60 adults in China, around the eyes, for 4 weeks. | Smoother skin than a dummy cream. |
Sources: Robinson 2005; Wang 2013; PubChem
Plain cream helps too. In one neck trial, the real and the dummy products both improved wrinkles and dryness.
Trying one? Take a photo in the same light today. Judge it again at 12 weeks, the length of the longer trial.
What is argireline, and does it work like Botox?
Argireline is a lab-made peptide. On labels it’s acetyl hexapeptide-8 or acetyl hexapeptide-3.
It copies part of a protein called SNAP-25. It’s reported to block a step in how cells release chemical messengers.
Is it Botox in a jar? No trial we found compares it with Botox injections.
The human proof is one trial. People used it twice a day around the eyes for 4 weeks.
On the doctors’ overall rating, argireline scored 48.9% for anti-wrinkle effect and the dummy cream scored 0%. That’s a rating score, not a 48.9% cut in wrinkles.
The claim that it builds collagen comes from a study in mice, not people. If you buy it, a small change is the most the trial suggests.
Can peptides get into your skin?
That number is 500. Two skin doctors argued a molecule must be under 500 Dalton to get through your skin’s outer layer. Dalton is the unit used to weigh molecules.
Think of a letterbox. Letters slide through. Parcels usually get stuck, however good they are.
- Below 500 DaltonUnder the 500 limit, so size isn’t a barrier.
- 500 Dalton or aboveThought too big to pass the outer layer.
Sources: Bos and Meinardi 2000; PubChem: argireline; PubChem: palmitoyl pentapeptide-4
Palmitoyl pentapeptide-4 weighs 802. Argireline weighs 887. Both still made small changes in trials, so size alone doesn’t rule them out.
But the 2017 review names size as one reason absorption may be poor. So judge a peptide by its trials, not the promise on the box.
Does a collagen peptide serum work?
Not as a way to add collagen. Whole collagen weighs about 300,000 Dalton, which is 600 times the 500 limit.
Even a review by authors at a collagen maker says whole collagen can’t pass the outer layer. That’s the parcel stuck at the letterbox.
Broken-down (hydrolysed) collagen is smaller, at 1,000 to 10,000 Dalton. The same review says it moisturises the skin’s surface.
So treat a collagen serum as a moisturiser. A plain cream does that job too, as our guide to moisturisers for ageing skin explains. Collagen you swallow is a separate question: see do collagen supplements work.
What are the best peptides for skin?
Palmitoyl pentapeptide-4 has the biggest peptide trial we found, then argireline. But two other buys have far stronger proof.
| Buy | Best trial | What it found |
|---|---|---|
| Daily sunscreen | 903 adults under 55, 4.5 years. | 24% less skin ageing than people using it when they chose. |
| Retinol 0.4% | 36 people, average age 87, arm skin (not face), 24 weeks. | Fewer fine wrinkles than plain lotion. |
| Palmitoyl pentapeptide-4 | 93 white women, for 12 weeks. | Fewer fine lines than the same cream without it. |
| Argireline | 60 adults, for 4 weeks. | Smoother skin around the eyes than a dummy cream. |
Sources: Hughes 2013; Kafi 2007; Robinson 2005; Wang 2013
How to spend on ageing skin
- Wear SPF 30 or higher with 4-star UVA every day, plus shade and clothing.
- Trying retinol? Start with the mildest one every other night, and skip it in pregnancy.
- Buying a peptide? Look for palmitoyl pentapeptide-4 or acetyl hexapeptide-8 in the ingredients.
- Treat a collagen serum as a moisturiser, not a collagen boost.
- Give a new product 12 weeks, then compare it with your first photo.
- Stop a product if your skin turns itchy, blistered, dry or cracked, or turns red, dark brown, purple or grey.
Sources: NHS: sunscreen; Hughes 2013; AAD: retinol; NHS: contact dermatitis
More on the top two: sunscreen and skin ageing and retinol and tretinoin.
When to speak to a GP
A skin reaction to a product usually shows within a few hours or days. Speak to a pharmacist if it’s troubling you. See a GP if:
- A skin reaction lasts, keeps coming back or is severe.
- A growth on your skin is getting bigger or has changed colour or texture.
- A growth or patch of skin hurts, itches, bleeds, crusts or scabs for more than 4 weeks.
- You have a new mole, or a mole has changed. The NHS says this may be a sign of melanoma.
Finding non-melanoma skin cancer early can mean it’s easier to treat.