What it is
Polylactic acid is a polymer built from repeating units of lactic acid, often supplied as fine spherical powder for cosmetic use. In formulas it can act as a film former and a texturizing or soft-focus agent that smooths the appearance of the skin surface and improves product feel. It is valued as a plant-derived, biodegradable alternative to some synthetic polymers and microplastic powders.
Safety & warnings
Polylactic acid is considered inert and well tolerated on the skin and is widely used in biomedical and cosmetic applications. As a particulate powder it has low irritation potential.
Origin & sourcing
Derived from lactic acid, which is typically produced by fermentation of plant sugars such as corn starch, then polymerized; it is therefore a bio-based, biodegradable polymer.
Questions everyone asks
Is polylactic acid a microplastic?
It is a polymer but is plant-derived and biodegradable, which distinguishes it from conventional persistent synthetic microplastic powders.
What does it do in a sunscreen?
It can act as a film former and soft-focus powder that smooths texture and improves the feel of the product on skin.