Do peptides in skincare actually do anything?

Skin ageing occurs because collagen-breaking enzymes become more active while the skin produces less new collagen. Sun damage accelerates this considerably. Peptides in skincare products attempt to influence this process, and there are now enough studies to say something meaningful about it.

Of all the ingredients studied in sun-damaged skin, peptides have the strongest evidence base within the 'cosmeceuticals' category. A systematic review concludes that most peptide studies have produced at least one randomised controlled trial, which is relatively solid for cosmetic ingredients. Four types work through different mechanisms: signal peptides (stimulate collagen production), enzyme inhibitors (inhibit collagen breakdown), neurotransmitter inhibitors, and peptides that carry active substances deeper into the skin.

One widely discussed type is the so-called 'botox peptide' (acetyl hexapeptide-8). Clinical studies suggest that it reduces wrinkle depth and makes the skin more elastic and better hydrated. But there is a serious question: this peptide is water-soluble and relatively large, which makes it difficult to penetrate the fatty outer skin layer. Whether it ever reaches the neuromuscular junctions the way a real botox injection does remains unknown. The positive results are therefore intriguing, but the mechanism of action has not yet been clarified.

Collagen as a supplement (drunk or ingested) is a separate matter. Placebo-controlled studies show higher skin moisture levels after eight weeks, and more collagen in the dermis after four weeks. Those effects persisted through to week twelve. A broader review of dozens of studies confirms this as well, although two of the authors were affiliated with a collagen manufacturer, which you should factor in when interpreting the findings. On social media, claims run far ahead of reality: studies are often small and the effects are inconsistent.

The true gold standard for skin rejuvenation remains tretinoin, a prescription medication. It is clinically proven and works more powerfully than any peptide. Peptides are a reasonably low-risk alternative for those who cannot or do not want to use a prescription, but do not expect the same result.