Peptides: What They Are and What They Can (Actually) Do
Peptides are everywhere in skincare marketing. Here is what the science actually supports, which types have the best evidence, and how to use them.
Peptides are short chains of amino acids — the building blocks of proteins. In skin, the relevant proteins are collagen and elastin. The idea behind peptide skincare is that applying these fragments signals the skin to produce more of those structural proteins.
The signalling theory
When collagen breaks down, it releases short peptide fragments. The skin reads these as a signal that repair is needed and increases collagen synthesis. Topical peptides may mimic this signal. The evidence is real but more modest than retinoid evidence — peptides work slowly and require consistent use.
Ingredient spotlight — Matrixyl (Palmitoyl Pentapeptide-4)
One of the best-studied signal peptides. Stimulates collagen and fibronectin production, reducing fine lines with consistent use.
Good for
- Anti-aging routines
- Fine lines and texture
- Sensitive skin that cannot tolerate retinoids
Use with caution if
- No known contraindications — peptides are generally very well-tolerated
Types of peptides
- Signal peptides — tell skin to produce more collagen (Matrixyl, Argireline at low doses).
- Carrier peptides — deliver minerals to skin (copper peptides are the main example, with some evidence for wound healing).
- Neurotransmitter-inhibiting peptides — claimed to relax muscle contractions (Argireline); evidence at cosmetic concentrations is weak.
Knowledge check
0 / 2 correct1. How do signal peptides like Matrixyl work?
2. Why should peptides be in leave-on (not rinse-off) products?
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