What it is
Zea Mays Starch is a natural polysaccharide powder obtained from the kernels of corn (maize). In sunscreens and other leave-on products it helps absorb excess oil and reduce surface shine, contributing a velvety, matte after-feel and helping to offset the greasiness or whitecast that can accompany certain UV filters. It is also used to bulk out powder phases and to fine-tune texture and slip.
Safety & warnings
Corn starch is broadly well tolerated on skin and is widely regarded as low-irritation and non-sensitizing. Because it is a fine carbohydrate powder, it can in principle support microbial growth if a product is poorly preserved or used on broken, weeping skin, so finished formulas rely on adequate preservation. It is generally considered to have low comedogenic potential.
Origin & sourcing
Natural; isolated from the starchy endosperm of corn (Zea mays) kernels through wet milling, then washed and dried into a fine powder.
Questions everyone asks
What does corn starch do in a sunscreen?
It acts as an absorbent and texturizer, soaking up excess oil to give a drier, more matte finish and helping reduce the heavy or greasy feel some sunscreens have.
Is Zea Mays Starch natural?
Yes. It is a plant-derived starch extracted from corn kernels and processed into a fine powder, with no synthetic modification in its basic form.