01
What is it?
Peptides are short chains of amino acids, the building blocks of proteins. “Peptides” does not identify one ingredient: cosmetics use signal, carrier, enzyme-inhibiting and neurotransmitter-modulating sequences, among other categories. Each pursues a different objective and has its own stability and penetration challenges. This is why the specific INCI name and formula information matter.
02
Its role in a formula
They may feature in formulas targeting firmness, texture, hydration or visible lines. Available evidence is promising for certain sequences and products, but peptides do not all work in the same way or interchangeably. Concentration, delivery system and stability throughout shelf life influence the result. The word “peptides” on the front label cannot establish efficacy on its own.
03
Compatibility and tolerance
They generally fit well with hyaluronic acid, niacinamide, ceramides and antioxidants. There is no universal rule requiring them to be separated from vitamin C either: the finished formula and individual tolerance matter. If exfoliants or retinoids cause sensitivity, simplify the routine or alternate days—not because the peptide is necessarily inactivated, but to reduce the total irritation burden.
04
How do I use it?
Apply after cleansing, usually before moisturiser, at the frequency indicated. There is no need to combine several peptide serums: one complete, well-preserved formula is usually a more sensible choice. Assess comfort and visible changes over several weeks. Consistency, adequate moisturising and daily sun protection add more value than accumulating many layers.