What it is
Ornithine is a non-protein amino acid that participates in natural metabolic pathways and is used in cosmetics for its water-affinity and conditioning properties. Applied topically, it helps support a hydrated, smooth skin surface. In sunscreens it serves as a supporting care ingredient and does not provide UV protection.
Safety & warnings
Amino acids such as ornithine are generally well tolerated at cosmetic use levels and are not associated with comedogenicity. Isolated sensitivity is uncommon but, as with any leave-on ingredient, possible.
Origin & sourcing
Typically synthetic or produced by fermentation; ornithine is an amino acid that can be manufactured to a defined cosmetic grade rather than relying on plant or animal extraction.
Questions everyone asks
What is ornithine in skincare?
It is an amino acid used as a humectant and skin-conditioning agent to support a hydrated, smooth-feeling skin surface.
Does ornithine filter UV?
No. It is a conditioning amino acid with no UV-filtering activity; the sunscreen's protection comes from its dedicated filters.