Peptides are in everything now: serums, moisturisers, eye creams, £8 bottles and £80 ones. The pitch is usually "signals your skin to make more collagen" which is a tidy sentence that skips the awkward bit: most of the evidence is smaller and quieter than the marketing, and peptides will not do a retinoid's job.
Here's what they actually are, which types are worth knowing, and how to use them without expecting a facelift in a dropper.
What peptides actually are
Peptides are short chains of amino acids, the same building blocks that make up proteins like collagen and elastin. In skincare they're used as messengers. A well-chosen peptide can, in principle, tell skin cells to do something useful: make more collagen, make fewer wrinkle-related contractions, or behave as if a bit of copper is around to help repair.
They are not exfoliants. They don't purge. They don't replace SPF, and they don't have the decades of clinical weight behind tretinoin or even over-the-counter retinol.
Think of them as a supporting actor for firmness and texture, especially if you can't use retinoids or you want something gentle in the morning.
The types that actually get discussed
Ingredient lists bury these under trademarked names. The useful categories:
Signal peptides (including palmitoyl pentapeptide-4, often sold as Matrixyl, and palmitoyl tripeptide-1 / palmitoyl tetrapeptide-7 blends). These are the "nudge collagen" group. Lab and small clinical studies show modest improvements in wrinkle appearance and firmness with consistent use. Modest is the word.
Copper peptides (GHK-Cu). Copper is a cofactor in collagen production, and GHK-Cu has a longer research trail than most cosmetic peptides, including wound-healing work. In leave-on skincare the effects are still incremental. Some people find copper peptides irritating or oddly reactive with vitamin C; if you use both, split AM/PM.
Neurotransmitter-inhibiting peptides (acetyl hexapeptide-8, "Argireline"). Marketed as topical Botox. They can slightly reduce the look of expression lines in some studies. They will not freeze your forehead. Anyone promising that is selling.
Carrier peptides ferry minerals such as copper or manganese. Often bundled into the copper-peptide story.
You do not need all of them. A moisturiser that already contains a peptide blend plus a retinoid at night is a complete anti-ageing pair for most people.
What they will and won't do
Will: support the look of firmness and fine lines over months, play nicely with almost everything, and give sensitive skin an anti-ageing option that isn't an acid or a retinoid.
Won't: lift sagging, erase deep wrinkles, treat acne, fade dark spots the way vitamin C or azelaic acid do, or repair a wrecked barrier as well as ceramides and panthenol.
If wrinkles are the main goal and your skin can tolerate it, a retinoid is still the evidence-backed centrepiece. Peptides are what you add around it, or use instead when retinoids are off the table (irritation, pregnancy, you're done with peeling).
How to use peptides
Where: after cleansing, as a serum, or just use a peptide moisturiser and skip the extra step. Layer thin to thick as usual.
When: morning, night, or both. They're not photosensitising.
With retinoids: yes. Peptides in the morning, retinoid at night is the clean split. Using a peptide moisturiser on top of retinol is also fine and often more comfortable.
With acids and vitamin C: generally fine. If a copper peptide stings with L-ascorbic acid, don't layer them.
Give it eight to twelve weeks. If nothing has changed, the peptide wasn't the bottleneck. SPF and a retinoid usually were.
Which products are worth buying
You do not need a luxury peptide cream to "get peptides." Concentration and the rest of the formula matter more than the brand story.
The Ordinary "Buffet" (now Multi-Peptide + HA) is the obvious cheap multi-peptide serum in the UK. Hydrating, unscented, unglamorous. A sensible first try.
The Ordinary Matrixyl 10% + HA if you want the Matrixyl family without the rest of the buffet.
The Inkey List Peptide Moisturizer if you'd rather one step than a serum plus cream.
Pricey peptide creams (the Drunk Elephant Protini type of product) are not doing secret biology the £10 bottles can't point at. The extra money is usually texture, packaging and extra supporting ingredients. A cheap multi-peptide serum plus a moisturiser you already like is a complete version of the same idea.
The verdict
Peptides are a reasonable, gentle extra for fine lines and the look of firmness. They are not a miracle, not Botox in a bottle, and not a substitute for sunscreen or a retinoid. If your routine already has SPF and a vitamin A product, a peptide serum is optional. If you can't use retinoids and want something to do in that slot, bakuchiol and peptides are two of the better gentle options: different jobs, neither is a retinol clone.
References
Gorouhi F, Maibach HI. Role of topical peptides in preventing or treating aged skin. Int J Cosmet Sci. 2009;31(5):327-345. (https://pubmed.ncbi.nlm.nih.gov/19735513/)
Pickart L, Margolina A. Regenerative and protective actions of the GHK-Cu peptide in the light of the new gene data. Int J Mol Sci. 2018;19(7):1987. (https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6075622/)
Lintner K, Peschard O. Biologically active peptides: from a laboratory bench curiosity to a functional skin care product. Int J Cosmet Sci. 2000;22(3):207-218. (https://pubmed.ncbi.nlm.nih.gov/18503456/)
FAQs
What do peptides do for your skin?
Mostly they act as messengers that can support collagen and the look of firmness and fine lines. The effect is modest and slow. They don't exfoliate or treat acne.
Do peptides really work?
They can, a bit, with consistent use over months. The evidence is weaker than for retinoids and sunscreen. Treat them as a supporting ingredient, not the main treatment.
Can I use peptides with retinol?
Yes. The simplest approach is peptides in the morning and retinol at night, or a peptide moisturiser over retinol.
Are copper peptides better than other peptides?
They have a more interesting research history, especially around repair. In everyday skincare they're still a supporting act, and some people find them more irritating than Matrixyl-type blends.
Do I need a peptide serum if I already use retinol?
No. Nice to have, not required. Spend the money on SPF and a retinoid you'll actually use before adding another bottle.