Ever wondered why lips are pinker than the rest of our bodies? As it turns out, it’s one of the reasons that we use chapstick.

See, the skin on our lips is really, really thin. We’re talking .5mm, three to five cell layers thin. Do you know how tiny a cell is?? Your lips also have a lot less melanin – the stuff that gives your skin color – than the rest of the body. Combine these two things with the fact that we’ve got tons of blood vessels huddled up under our skin and it all starts to make sense. The reason lips appear pinker is because all those blood vessels are visible through the translucent skin on our lips. With such thin skin and that blood vessel (and nerve) party going on, it’s no wonder that kissing is so fun.

Unlike the rest of our skin, our lips don’t produce oil or sweat, meaning that all that thin skin is left unprotected. Lip balms are made up of barriers, emollients, and humectants that stand guard so that our lips stay moisturized.

Oils like olive oil, coconut oil, and avocado oil moisturize lips while waxes like beeswax and carnauba wax create a barrier that seals in the moisture.

Ever heard that lip balm can be addictive? That’s because some lip balms contain alcohol. Alcohols dry your lips out – think of it as a tiny lip hangover – causing you to reapply your lip balm more often. Others contains sugars that make you want to lick your lips. Unfortunately, saliva dries them out too, causing a vicious circle of chapstick wastefulness.