What it is
Melatonin is a small indoleamine molecule found naturally in humans, animals, and plants. In topical cosmetics it is included as an antioxidant that helps defend skin against free radicals and oxidative stress and as a conditioning agent. In sunscreens it is used as a supporting antioxidant alongside the UV filters rather than providing filtration itself.
Safety & warnings
At the levels used in topical cosmetics melatonin is generally well tolerated. It is used here as a topical antioxidant, and no oral or systemic effects are implied by its presence in a skincare formula.
Origin & sourcing
Occurs naturally in living organisms; the grade used in cosmetics is typically produced synthetically to a consistent purity.
Questions everyone asks
What does melatonin do in skincare?
On skin it acts as an antioxidant that helps protect against oxidative stress and as a conditioning ingredient; it is not a UV filter.
Is topical melatonin a sleep aid?
No. In a skincare or sunscreen formula it is used for its topical antioxidant and conditioning properties, not for any sleep-related effect.