Every bathroom is filled with creams, pastes and gels that we use to keep ourselves looking, feeling and smelling fresh. But despite how often we put the those products on (and in!) our bodies, most of us have no idea how they work. To find out exactly what’s going on when that stuff hits our skin, we had a chat with chemist and product wiz Fadi Mourad. Here’s what he had to say.
Toothpaste keeps your mouth kissable with the help of three main components: An abrasive; an active ingredient that prevents tooth decay; and a flavoring agent. The abrasive does exactly what it sounds like it does—it scrubs away stains and plaque, which in turn, keep bad breath at bay. The active ingredient that prevents tooth decay is most likely fluoride, according to Mourad, which strengthens the outer surface of your teeth (aka, the enamel), making it more resistant to erosion. Lastly, that intense flavoring agent hangs around your mouth to keep it smelling fresh.
The oils that your scalp produces are hydrophobic, meaning they can’t be washed away with just water. That’s where shampoo comes to the rescue. “Mild surfactants [cleaning agents] in shampoo remove oils, dirt and product buildup,” Fadi explains. These surfactants are both hydrophobic and hydrophilic (that is, attracted to water), so once their hydrophobic ends have latched onto the oils in your hair—and whatever gunk is mixed in with them—their hydrophilic ends strip those oils away when you rinse the shampoo out with water.
To understand how conditioner works, you first need to understand the structure of your hair. Every hair on your head is made up of dead skin cells, overlapping to form what’s called a cuticle layer. This layer protects the inner layers of the hair strand. When your hair looks frizzy, it’s because those overlapping cells that make up the cuticle layer are no longer lying flat: Conditioners help fix this with ingredients called cationic surfactants, which wrap themselves around the hair strand, pushing the dead skin cells back into place and leaving your hair feeling silky smooth.
Much like shampoo, Fadi explains that soaps contain mild surfactants that grab ahold of dirt and grime like a magnet, then wash the whole mess down the drain. That doesn’t mean you don’t have to really scrub yourself with the stuff, though: As we learned in a previous discussion about whether soapy runoff can actually keep your feet clean, it’s the scrubbing that actually removes the soap-coated crud from your skin.
In addition to providing a sort of buffer between the skin and the razor, shave butter is formulated with skin and hair softening agents (like those found in conditioners), according to Fadi. These ingredients soften the hair, making for an easier shave, then leave your face feeling soft when that hair’s all gone. It also goes on clear, which allows you to see exactly what you’re shaving, which is especially helpful when accurately trimming your neckline.
Much like a shaving foam, shave lather works more or less the same way shave butter does. The only difference is that shave lather is extra thick, which provides more of a protective cushion—something that’s essential for those prone to irritation and razor bumps. The downside is it goes on white, so you won’t be able to see exactly where you’re shaving like you would with shave butter.
Most toilet papers are made of cellulose pulp paper, which is strong when dry, but dissolves when wet (water molecules, like those in the toilet bowl, work their way in between the cellulose chains that make up the TP, ultimating dissolving the paper). As far as your butt is concerned, though, Fadi says plain old toilet paper isn’t the best: “Toilet paper doesn’t provide any soothing or cleansing attributes,” he says. For that, you’re going to need a wet wipe.