Peptides are short chains of amino acids, the building blocks of proteins like collagen, elastin, and keratin. In skin care, they act as signaling molecules that tell skin cells to carry out specific tasks, such as producing more collagen, repairing damage, or calming irritation.

Main types

Signal peptides (e.g., Matrixyl, palmitoyl pentapeptide) encourage collagen and elastin production, targeting fine lines and loss of firmness.

Carrier peptides (e.g., copper peptides) deliver trace minerals that support wound healing and skin repair.

Neurotransmitter-inhibiting peptides (e.g., Argireline) may soften the look of expression lines by reducing muscle contraction signals, often called a "gentle alternative to Botox," though the effect is far milder.

Enzyme-inhibiting peptides help slow the breakdown of existing collagen.

Benefits

Smoother, firmer-looking skin

Reduced appearance of fine lines and wrinkles

Improved hydration and barrier support

Generally well tolerated, making them a good option for sensitive skin or for people who find retinoids too harsh