Peptides: what they can do, and what they cannot

Peptides sit on a lot of expensive labels, usually next to a promise about firmness. They are worth having in a routine, and they are also the ingredient where the gap between the marketing and the evidence is widest.

Here is what is reasonable to expect.

What a peptide is

A peptide is a short chain of amino acids. Amino acids are what proteins are built from, and collagen and elastin are proteins. So peptides are fragments of the same material your skin uses for its structure.

The interesting part is what those fragments signal. When collagen breaks down, it leaves specific fragments behind. Your skin reads those fragments as damage and responds by making more collagen. Apply similar fragments on purpose, and you can nudge that same response without any damage having occurred.

That is the theory, and it is a good one. The question is how much of it survives contact with real skin.

What the evidence supports

Modest, gradual improvement in firmness and fine lines, over months, with consistent use. Several peptides have studies behind them showing measurable effects, and the effects are real.

They are also smaller than what retinol does, and the research base is thinner. Much of it is funded by the companies that sell the ingredient, done on small groups, or performed on skin cells in a dish rather than on faces.

That does not make peptides useless. It makes them a supporting ingredient rather than the centre of a routine. If you have room for one active, retinol has the better case. If you already have a routine that works, peptides are a sensible thing to add.

The botox comparison

You will see peptides described as botox in a jar. That refers to a specific group, argireline being the best known, which is meant to interfere with the signal between nerve and muscle.

The comparison does not hold. Botulinum toxin is injected into a muscle. A cream sits on the surface, and the muscles that cause expression lines are well below where anything applied topically reaches. Some of these peptides do appear to soften the look of fine lines a little, most likely by hydrating and smoothing the surface. That is a real but much smaller effect, and a different mechanism.

Why they are usually in night products

Peptides do not conflict with light or air the way vitamin C does, so evening use is not strictly necessary. But your skin does most of its repair overnight, and peptides work with repair processes rather than against congestion or pigment. Putting them in the last step of the evening means they sit undisturbed on the skin for hours.

They also combine well with almost everything: niacinamide, ceramides, hyaluronic acid, retinol. There is no combination to avoid here, which is unusual for an active.

Where ours sit

Dewy Dream contains Palmitoyl Tripeptide-1 and Palmitoyl Tetrapeptide-7, two of the better-studied signalling peptides, alongside Ceramide NP, niacinamide and hyaluronic acid. The combination is deliberate: peptides work on the structure underneath while the ceramides and niacinamide keep the barrier in shape.

Complexion Care has a peptide alongside its retinol, for the same reason niacinamide is in there. Retinol does the heavy lifting; the rest of the formula is there to make that tolerable.

Frequently asked questions

How long before I see something?

Three months at minimum, and the change is gradual rather than obvious. If a peptide product promises visible results in two weeks, that is hydration you are seeing.

Can I use peptides with retinol?

Yes, and they sit well together. Peptides do not irritate and do not compete with retinol.

Do collagen creams work?

Collagen itself is far too large a molecule to get into the skin, so a cream containing collagen works as a surface moisturiser. Peptides are the fragments small enough to matter, which is the whole reason they exist as an ingredient.

Are peptides worth the price?

As part of a formula, yes. As the reason to pay a large premium for a single product, be sceptical. Look at what else is in there.

Sources

• Schagen SK, Topical peptide treatments with effective anti-aging results, Cosmetics, 2017.
• Errante F et al., Cosmeceutical peptides in the framework of biomedical applications, Frontiers in Pharmacology, 2020.