You may have heard that the glycerin found in some leave-in conditioners can subdue frizzy, natural hair on hot, humid days. But is this fact or fiction? offers an answer.

Here are the basics: Glycerin (also called glycerol or glycerine) is a humectant (meaning it absorbs water from other sources) naturally present in animal and vegetable fats and can also be synthetically manufactured through a chemical process. Many moisturizers, lotions and natural soaps contain glycerin as a main ingredient, and it can also be found in hair moisturizers and in leave-in conditioners. In addition, there’s some evidence that glycerin combined with other ingredients, such as antioxidants, emollients and oils, can improve skin health. But 100 percent pure glycerin can dry out skin by drawing moisture from lower layers and pushing it into skin’s top layer, where water easily evaporates or is lost to the environment.

When it comes to glycerin in hair products, its properties as a humectant can bind to moisture in the environment and benefit dry or highly textured tresses. What’s more, glycerin may also offer benefits to the hair of those who live in mild spring or fall climates.

But for those who live in places with high levels of humidity, adding a glycerin-based product to frizzy strands usually backfires. The humectant weighs down strands with excess moisture making manes more unmanageable. What’s more, if glycerin-based products are applied to hair in especially cold or arid, desert-like climates, the humectant won’t be able to attract water strands from the outside environment. This ends up drawing moisture from the hair’s inner cortex where it’s needed most.

What’s the take away? Simply this: Check the ingredients in your hair products seasonally. Remember, the same glycerin that may add fresh moisture to your mane during spring months may also contribute to persistent summer frizz.

Want some more good advice? Click here to learn how to establish a hair-care regimen that protects your tresses during summer heat waves.