Beeswax
In plain terms
A natural wax from honeycomb, used to thicken and give body to balms, creams, and lip products and to seal in moisture. It is well tolerated, with allergy to it uncommon.
What the evidence shows
Beeswax is the wax that honeybees build their comb from, refined for cosmetics into either its natural yellow form or a bleached white one. It does the structural work in a formula, thickening balms and creams, stabilizing emulsions, and forming a light breathable seal that holds moisture on skin. Its safety profile is quiet and well established. The US cosmetic-ingredient panel reviewed the waxes and found beeswax safe as used, it is cleared as a food ingredient, and it carries no hormone, cancer, or contamination concern. Allergy to beeswax itself is uncommon; where reactions to a beeswax-containing lip balm do occur, they often trace to propolis, the resinous bee glue that can travel with less-refined wax, rather than the wax itself. People with a known bee-product allergy are the ones who should be cautious. For the rest, beeswax is a gentle, time-tested base ingredient.
On the label
Listed as beeswax, cera alba (white or refined), or cera flava (yellow). Reactions are uncommon and often trace to propolis carried along with less-refined wax; if you have a bee-product allergy, patch test, otherwise it is a gentle base.