If you’re regularly reading the ingredient lists of skincare products before you try them out—as we recommend you do!—it can be perplexing to come across an ingredient you’re unfamiliar with. One such ingredient that you might have noticed in your skincare, haircare, and cosmetic products is dipropylene glycol. A chemical name like dipropylene glycol can sound intimidating, and it’s no surprise that you may want to learn more about it. 

So what exactly is dipropylene glycol, and why is it used in skincare? Is putting this substance on your skin safe? We asked Curology’s team of licensed dermatology providers to answer these questions and share what you need to know about this prevalent skincare ingredient.

What is dipropylene glycol?

Although the name can sound a little scary, dipropylene glycol is nothing more than a type of alcohol. Alcohols are a broad category of chemicals with different characteristics and effects: Dipropylene glycol is a virtually colorless and odorless liquid used in the cosmetic, pharmaceutical, food, and chemical industries.¹

Using dipropylene glycol in skincare

Dipropylene glycol is in an abundance of cosmetic products. It’s often added to cleansers, moisturizers, sunscreens, deodorants, shampoos, conditioners, and perfumes.

Dipropylene glycol is considered to be a chemical permeation enhancer, which helps to modify the structure of the outermost skin layer, the stratum corneum, so that its accompanying substance can more easily penetrate this barrier.² This is one of the characteristics that make dipropylene glycol valuable for use in skincare products: medications and active ingredients are able to penetrate deeper into the skin, where they can be most beneficial, rather than sitting on the skin’s surface. Plus, it functions as a useful solvent as it’s not only completely soluble in water but can also dissolve oils.³ 

Further, dipropylene glycol is a humectant that attracts and retains moisture, helping the skin stay more hydrated.⁴ So, it is a very useful ingredient in cosmetics. 

Is dipropylene glycol safe for the skin? 

The US Environmental Protection Agency (EPA) has determined that under the current conditions of use based on its low-hazard profile, dipropylene glycol is generally considered safe for skin and hair care products.⁵ However, dipropylene glycol can cause contact dermatitis in some people.⁶ We recommend doing a patch test before using a new product to see if your skin can tolerate it. 

The skincare and cosmetics industries are experiencing a powerful marketing trend called “greenwashing.”⁷ This tactic makes consumers think that a product is better for them if it has easy-to-read ingredients and words like “organic” or “all-natural” on the label. The truth is that greenwashed products may be more likely to use misleading advertising and be less regulated than other products.⁸ You might be wasting your hard-earned money on products that don’t deliver on their promises and may cause irritation and other unwanted side effects.

Because of the chemical-sounding name, some people who believe they should only use “natural” products may be wary of dipropylene glycol. In fact, they may think that something “all-natural” should automatically imply that they’re “safe.” Many non-greenwashed products, including manufactured chemicals, may in fact be safer than their greenwashed counterparts because they undergo stricter quality control, testing, and regulation before being introduced to the public. 

So, in essence, dipropylene glycol is nontoxic and has minimal adverse effects.⁹ The most severe symptom reported is minor skin irritation in some people after prolonged exposure. Research has shown that dipropylene glycol is gentle and does not readily cause eye or respiratory irritation.¹⁰

Is dipropylene glycol good for hair?

Dipropylene glycol brings humectant qualities to the hair and the skin, helping combat dryness by attracting and retaining moisture. It also improves the texture of shampoos and conditioners, giving the user a more enjoyable hair care experience. 

Try personalized skincare with Curology

Dipropylene glycol is commonly used in cosmetic and skincare products, and for good reason. Aside from the minor risk of an allergic reaction that comes with any skincare ingredient, dipropylene glycol is generally considered safe and has benefits that make it a valuable and versatile ingredient in many different applications. It’s a good idea to go slow with products that contain new ingredients to see how your skin will react, but chances are, you’ve already used products containing dipropylene glycol with no problems. 

Get your personalized skincare routine with Curology

Get your personalized skincare routine with Curology

Start your skin quiz

If you have more questions about specific ingredients or want to take the guesswork out of your skincare routine, Curology is here to help. Our licensed dermatology providers are happy to answer your questions and help you create a skincare solution tailored to your individual needs. Sign up at Curology* today for a consultation with one of our medical providers and take the first step on your personalized skincare journey. 

P.S. We did the homework, so you don’t have to: 

1. Office of Pollution Prevention and Toxics. Supporting Information for Low-Priority Substance Propanol, Oxybis-(CASRN 25265-71-8) (Dipropylene Glycol) Final Designation. U.S. Environmental Protection Agency. (2020, February 20).

2. Kis, N., et al. The effects of glycols on molecular mobility, structure, and permeability in stratum corneum. J Control Release. (March 2022).

3. Office of Pollution Prevention and Toxics. Supporting Information for Low-Priority Substance Propanol, Oxybis-(CASRN 25265-71-8) (Dipropylene Glycol) Final Designation. U.S. Environmental Protection Agency. Ibid.

4. Office of Pollution Prevention and Toxics. Supporting Information for Low-Priority Substance Propanol, Oxybis-(CASRN 25265-71-8) (Dipropylene Glycol) Final Designation. U.S. Environmental Protection Agency. Ibid.

5. Office of Pollution Prevention and Toxics. Supporting Information for Low-Priority Substance Propanol, Oxybis-(CASRN 25265-71-8) (Dipropylene Glycol) Final Designation. U.S. Environmental Protection Agency. Ibid.

6. Peterson, M.Y., et al. Allergic contact dermatitis from dipropylene glycol in hydrocortisone lotion. Contact Dermatitis. (2022, March 23).

7. Dahl, R. Green Washing. Environ Health Perspect. (June 2010).

8. Dahl, R. Green Washing. Environ Health Perspect. Ibid.

9. Johansen, J.D., et al. Contact sensitization to dipropylene glycol in an eczema population. Contact Dermatitis. (September 1995).

10. Dalton, P.., et al. Lack of respiratory and ocular effects following acute propylene glycol exposure in healthy humans. Inhal Toxicol. (February 2018). 

11. National Toxicology Program. Toxicology and Carcinogenesis Studies of Dipropylene Glycol in F344/N Rats and B6C3F1 Mice (Drinking Water Studies). U.S. Department of Health and Human Services. (June 2004). 

Erin Pate is a board-certified Family Nurse Practitioner at Curology. She earned her Masters of Science in Nursing at Florida Atlantic University in Boca Raton, FL.

*Cancel anytime. Subject to consultation. Results may vary.

Written by

Curology Team

Medically reviewed by

Erin Pate, NP-C