Peptides

Short chains of amino acids used in skincare with several proposed mechanisms: signal peptides (e.g. palmitoyl pentapeptide-4/Matrixyl) aim to stimulate collagen synthesis; carrier peptides deliver minerals like copper to facilitate wound repair; neurotransmitter-inhibiting peptides (e.g. acetyl hexapeptide-3/Argireline) claim to reduce muscle contractions mimicking Botox. Most compelling evidence is in vitro or funded by ingredient manufacturers. Human RCT evidence for clinically meaningful changes at OTC concentrations is limited. Generally safe and non-sensitising; whether they deliver on anti-aging claims remains uncertain.