Collagen is a naturally occurring protein in our skin that makes it look healthy and plump. Collagen found in skin care products and supplements is derived from animal sources (bovine and fish), though vegan sources—like fermented algae—are also an option. Applied topically, collagen softens and moisturizes skin, visibly minimizes wrinkles, and makes skin look plumper. 

Peptides are amino acids that are the building blocks of certain proteins needed by the skin, like collagen and elastin. More specifically, collagen is made of three polypeptide chains, so adding peptides can stimulate your skin to make collagen. More collagen can lead to firmer, younger-looking skin. Using a serum or moisturizer that contains peptides can lead to firmer, younger-looking skin and maybe even fewer breakouts.