Glycerin: A Nearly Ubiquitous Ingredient

Not only does glycerin add a kick to curls, but it also helps to smooth and coat the hair shaft.

“Shampoos can be a little bit dry and the glycerin acts kind of like a buffer,” Coulton explains.

Still, Coulton reminds curlies there are several factors that affect the way your locks are affected by glycerin.

“If you use it and you’re in a super dry climate, it will pull moisture — not from the air, but from your hair — so you have to be careful,” Coulton says. “If you’re going to use it, it needs to be in combination with other moisturizing ingredients — maybe some oils and water — so even if you’re in that dry climate, it doesn’t have a drying effect on your hair.”

Glycerin is one of those ingredients that plays well with others and can also fairly easily be compounded in most products, according to Davis. “Other ingredients may not be as stable or easily formulated into a product,” he says.

Dr. Ali D. Ghannad, vice president of research and development for Farouk Systems agrees. “If I have a product that is thick and I need to put something to decrease the viscosity or thickness, I may use glycerin because it doesn’t hurt my product but helps by being moisturizing,” Ghannad says. “If you use too much, though, your hair becomes tacky or sticky.”

In fact, Coulton cautions curlies not to run out and buy glycerin to tame their tresses.

“Even if you have thick hair, don’t put glycerin on straight,” Coulton says. “You want to look for it in your products, but you’ll have to try different ones to see that the amounts are right for your hair type.”