What Is Diglycerin?
Diglycerin, also known by its chemical name oxybispropanediol, is a clear syrup-like liquid made by linking two glycerin molecules together. It is usually sourced from plant-based glycerin that comes out of the soap or biodiesel industries, making it a renewable ingredient. The material became popular in cosmetics in the early 2000s when formulators looked for alternatives to standard glycerin that could hold more water yet feel less sticky on the skin.
Manufacturers create diglycerin by heating purified glycerin in the presence of a catalyst. This controlled process joins the molecules while driving off water, after which the mixture is cooled and filtered to remove any leftovers from the reaction. The result is a high-purity liquid that blends easily with water and many other cosmetic ingredients.
You will often spot diglycerin in leave-on products like moisturizers, serums, eye creams and anti-aging formulas. It also shows up in wash-off items such as cleansers, face masks and shower gels where a boost of moisture is desired without a heavy feel.
Diglycerin’s Cosmetic Benefits/Uses
Diglycerin serves more than one purpose in skin care formulas
- Humectant: It attracts water from the environment and from deeper skin layers, helping products stay moist and keeping the skin surface hydrated for longer than regular glycerin can
- Skin conditioning: By smoothing out rough spots and softening the outer skin layer it improves overall texture and leaves a comfortable finish
Who Can Use Diglycerin
Diglycerin is well tolerated by most skin types including dry, normal, combination, oily and sensitive skins because it is non-occlusive and has a low risk of irritation. Very sensitive or highly reactive skin may still prefer to introduce any new moisturizer slowly but there are no known reasons to avoid diglycerin specifically.
The ingredient is typically sourced from vegetable glycerin with no animal-derived additives, making it suitable for vegans and vegetarians. Brands that certify their supply chain can further guarantee this status.
Current safety assessments show no evidence that topical diglycerin affects pregnancy or lactation. That said this is not medical advice and anyone who is pregnant or breastfeeding should discuss all personal care products with a qualified healthcare provider.
Diglycerin does not absorb UV light and it does not make skin more sensitive to the sun, so there is no added photosensitivity risk. It can be used day or night and pairs well with sunscreen in daytime routines.
Potential Side Effects/Adverse Reactions
Individual responses to any cosmetic ingredient can vary. The issues listed below are only potential side effects and most people will not experience them when using a well-formulated product containing diglycerin.
- Mild stinging or tingling a temporary sensation that can occur if skin is already compromised or very dry
- Redness or irritation usually connected to very high use levels or to other actives in the same formula rather than the diglycerin itself
- Allergic contact dermatitis an uncommon reaction in which the immune system becomes sensitized to the molecule leading to itching swelling or rash
- Enhanced penetration of other ingredients its strong water-binding ability can in rare cases increase skin uptake of harsher actives present in the product and amplify their irritation potential
If any discomfort or visible reaction occurs stop using the product and seek guidance from a dermatologist or healthcare professional.
Comedogenic Rating
Diglycerin has a comedogenic rating of 0. Being a fully water-soluble humectant it does not form an oily film or sit in pores, so it is very unlikely to trap sebum or dead skin cells. Its molecular structure is similar to glycerin, which is widely accepted as non-clogging. As a result, products containing diglycerin are generally suitable for people prone to acne or breakouts. Because it is hygroscopic it can actually help keep pores clear by drawing water to the skin surface instead of excess oil. No additional comedogenic concerns have been reported in the scientific or consumer literature.
Summary
Diglycerin works mainly as a humectant and skin-conditioning agent. It binds water from the air and the deeper layers of the skin, increasing moisture levels and leaving the surface softer and smoother. The dual glycerin units give it stronger water-holding power than regular glycerin while feeling less tacky, making it a handy choice for lightweight creams, serums and cleansers.
The ingredient enjoys moderate popularity: it is not as ubiquitous as glycerin but formulators looking for extra hydration without stickiness reach for it often, especially in premium or sensitive-skin lines.
Current safety data shows diglycerin is low risk, non-sensitizing and non-comedogenic. Still, whenever you try a new product it is smart to perform a small patch test first to make sure your individual skin agrees with the full formula.