Scan the label of any moisturizer or lotion, and you're likely to see a recurring ingredient: glycerin. Glycerin has been quietly dominating the skincare arena for years as part of many popular formulas. Recently, the beauty community has begun to seek it out on its own to treat a variety of skin issues.
Glycerin is a sugar alcohol that can be derived from a range of sources including animal products, plants, and petroleum or synthetically-made. It is specifically classified as a humectant.
Glycerin is effective as a moisturizer because it acts as a humectant, pulling moisture from the environment and deep within the skin to the surface, which needs the moisture most. Many hair types suffer from dryness and could benefit from the moisture boost glycerin provides to the skin's surface.
Is glycerin the answer to dry, dull hair? We turned to board-certified dermatologist Ava Shamban and BosleyMD-certified trichologist Gretchen Friese for their expertise on using glycerin for hair and scalp health.
Meet the Expert
Ava Shamban is a board-certified dermatologist.
Gretchen Friese is a BosleyMD-certified trichologist
Glycerin
Type of ingredient: Hydrator and antimicrobial
Main benefits: Hydrates the scalp, eliminates breakage, and fosters a healthy scalp environment.
Who should use it: In general, anyone with thick, coarse, dry, or dehydrated hair, but can be beneficial to all hair types. Those with freshly colored hair may want to avoid use until after 1-2 washes.
How often can you use it: It should be applied weekly to observe results and can be used up to 3 times weekly.
Works well with: Aloe vera
Don’t use with: There are no known ingredients that negatively interfere with glycerin.
Glycerin, or glycerol, is known to be the most effective humectant. As such, it draws in moisture to the hair and scalp. Additionally, it helps to create a barrier to prevent moisture from leaving the skin and hair follicles. Shamban explains that "it has a small molecular size and can draw in moisture into the cells of both scalp and hair." This can be especially helpful during the dry winter months when dry scalp conditions may lead to itching and flaking.
Glycerin's ability to attract and maintain moisture makes it extremely beneficial to the scalp's overall health. Adequate hydration of the scalp's skin can prevent a host of issues, including dandruff and oil overproduction. Healthy hair starts at the scalp, making scalp health paramount in treating hair concerns.
Our experts agree that glycerin is safe for all hair types but can be especially beneficial to those with thick, coarse, dry, or dehydrated hair. Shamban illustrates the effect glycerin can have on coarse or curly hair, saying, "there is a range of porosity for hair that dictates the efficiency of humectants and oils passing through the cuticle. The more tightly bound the hair, the less porous the hair. With high porosity and a more open cuticle, the hair has better absorption of glycerin leading to improved hydration." Friese does caution use of glycerin on freshly colored hair, as it may strip color. She recommends waiting one-to-two washes before using glycerin in colored hair. Both experts agree that glycerin reactions are uncommon, but a patch test should be conducted before using it all over the hair and scalp.
Glycerin is already found in many commonly used beauty products, making it easy to incorporate into your routine. Those looking to take full advantage of its effects should source glycerin in its pure form. However, Shamban urges the importance of researching the purity, derivation or source, and strength when purchasing glycerin. She cautions that it can be highly occlusive on its own and needs to be diluted.