Propylene glycol in skin care is a hot topic that consumers, patients, and physicians are becoming more aware of and have a heightened interest in.

In this article, we break down exactly what this ingredient is, how it is used, potential advantages and disadvantages, and what to know or consider.

Propylene glycol is a commonly used vehicle that is used topically in many skincare and personal care items. It is commonly found in topical preparations.

What is propylene glycol?

Propylene glycol is a substance that is a synthetic liquid that absorbs water. According to the FDA (Food and Drug Administration), it is used as an additive that is generally safe to add in food.(1)

It absorbs water and maintains moisture in food products, medications, cosmetics, and skincare products.

It has many uses in other industries such as paint, plastic manufacturing, food coloring, and to create fog and artificial smoke used in theater productions and training for firefighters.(1)

At room temperatures, propylene glycol is a colorless, clear, and slightly syrupy liquid. It is also tasteless and does not have an odor. It can also exist as a vapor form though it must be shaken or heated to change into this vehicle form.(1)

What is propylene glycol made from?

Propylene glycol is made from petroleum. However, the petrolatum from which it is derived is of a cosmetic-grade and is not carcinogenic or toxic when used in skincare.(2–3)

Many safe chemicals and products can be derived from toxic parents; however, the final say for what matters from a safety perspective is its final chemical and structural form.(4)

Propylene glycol uses

Propylene glycol is used as a preservative vehicle in topicals and some medications. Propylene glycol is an organic compound with multiple uses, including as a food additive, drug solvent, and a moisturizer in cosmetics, skincare, medicines, and tobacco products.(1)

It is used as an emulsifier and emollient found in food, medications, and cosmetics. Various irritant, contact, and other systemic irritating reactions have been documented for propylene glycol, which has become increasingly common as an ingredient.(5)

In skincare, it is used in small amounts to keep the product from melting at high temperatures or freezing at lower temperatures, therefore retaining its natural vehicle formulation. It can also be used as a humectant to keep the skin moisturized.

However, there are better moisturizers available that can hydrate the skin.

Propylene glycol in skincare and cosmetics

Propylene glycol is found in skincare and cosmetics as well as other personal care items. Many emollients and moisturizers contain a wide variety of compounds that range from esters to long-chain alcohols, such as propylene glycol, dimethicone, castor oil, isopropyl isostearate, and octyl stearate.(6)

Unless contamination is a problem at a lab, factory, or in the chemical composition, being a derivative of petroleum does not necessarily make propylene glycol particularly harmful. Its final form is found in many topical cosmetic and skincare products and is not considered carcinogenic in this state.

Propylene glycol can penetrate the skin, although absorption is minimal. However, if applied to a large body surface area of a compromised skin barrier (for example – burned skin), it can get into the bloodstream, causing problems.

It should not be applied on skin that is missing its outermost protective layer, such as burned skin. In some cases, lactic acidosis and abnormal serum osmolalities may be observed when applied to compromised skin.

These problems are minimized when applying the ingredient to intact, healthy skin with a normal skin barrier.

Is propylene glycol safe?

It is controversial as an ingredient as it is ubiquitous and commonly found as an irritant and weak sensitizer, occasionally confounding results of patch testing to rule out possible allergens.(6–7)

While propylene glycol is not bad for you or unsafe per se, it is capable of producing allergic sensitization and primary irritant reactions in the skin. There is a specific subset of the population that is sensitive to propylene glycol as an ingredient.(5, 7–8)

Propylene glycol can occasionally be harmful or offensive to some users, which granted it the spot of the American Contact Dermatitis Society’s Allergen of the year in 2018.

Suppose someone develops an itchy, reddish dermatitis after applying certain skincare, haircare, or makeup product. In that case, they are likely experiencing allergic contact dermatitis to one of its ingredients – in these cases, as dermatologists and allergists, we find that propylene glycol is often the one to blame.(7–8)

Also, individuals with a history of eczema or sensitive skin may be more sensitive to this ingredient than others.

What to do in this case? If unsure, you may benefit from patch testing with an allergist or dermatologist.

For moisturizers that are organic and made of plant-based ingredients that do not contain parabens, silicones, phthalates, or petrochemicals, consider trying the ZELEN Life Moisturizer and the ZELEN Life Night Cream.

If you have sensitive skin, you may benefit from checking out this article on the best hypoallergenic moisturizers for sensitive skin.

Also, the Mayo Clinic has found that increased concentrations of propylene glycol in skincare and other products are directly associated with increased reactions, both allergic and irritant patch test reactions.(7)

Greater awareness of propylene glycol is needed regarding sensitization, appropriate testing, and evaluation of patch testing and other exams that may distinguish if one has a true allergy to this ingredient.(9)

Propylene glycol and acne

There are moisturizers with different properties such as anti-inflammatory, salicylic acid, benzoyl peroxide, and retinol that are geared towards acne. They also have propylene glycol.

On the other hand, there are also anti-inflammatory moisturizers and emollients without any acne preparations.

For some individuals, propylene glycol is safe for acne as it is not oily. It may help to heal the skin with time and fade acne. However, it should be avoided, or some people who may have experienced a contact allergy to it, causing redness, itching, and a rash.

As an irritant, it may also contribute to acne as we know that impaired skin barriers and epidermal insults lead to increased breakouts of rashes and acne, among other skin conditions.

To avoid possible acne breakouts, here are some products geared towards acne-prone skin that cleanse and exfoliate the skin.

The ZELEN Life Cleanser provides deep cleansing and avoids acne breakouts, the ZELEN Life Toner, which clears excess residue and purifies the skin, and the ZELEN Life Exfoliator, which is a daily scrub ideal for all skin types.

All are free of petrochemicals, non-comedogenic, and hypoallergenic. If you have acne or acne-prone skin, you may also benefit from reading this article on the best natural face moisturizers for acne-prone skin.

Conclusion

Propylene glycol is considered a common additive in skincare but can also be an allergen.

Regarding propylene glycol in skincare, as an individual, it is always helpful to be knowledgeable about chemicals and ingredients you may use or place on your skin.

While propylene glycol is not harmful to most individuals, it can have some unwanted side effects for those with sensitive skin or an impaired skin barrier.

Have you had any experiences or allergic reactions to preservatives and additives in skincare? If so, which ones?

If you know anyone who is curious about learning more regarding preservatives and propylene glycol in makeup, skincare, haircare, and cosmeceuticals, please feel free to comment and share this article.

You may also want to consider subscribing to our email list for the latest updates on the science and makeup behind skincare. By signing up, you’ll receive subscriber-only exclusive skincare tips and how-to pointers that will help you achieve healthy, glowing skin and guide you to looking your best.

References

1. National Center for Biotechnology Information (2020). PubChem Compound Summary for CID 1030, Propylene glycol. Retrieved November 20, 2020 from https://pubchem.ncbi.nlm.nih.gov/compound/Propylene-glycol.

2. Lau K, Swiney BS, Reeves N, Noguchi KK, Farber NB. Propylene glycol produces excessive apoptosis in the developing mouse brain, alone and in combination with phenobarbital. Pediatr Res. 2012;71(1):54-62. doi:10.1038/pr.2011.12

3. Lim TY, Poole RL, Pageler NM. Propylene glycol toxicity in children. J Pediatr Pharmacol Ther. 2014;19(4):277-282. doi:10.5863/1551-6776-19.4.277

4. Fowles JR, Banton MI, Pottenger LH. A toxicological review of the propylene glycols. Crit Rev Toxicol. 2013 Apr;43(4):363-90. doi: 10.3109/10408444.2013.792328. PMID: 23656560.

5. McGowan MA, Scheman A, Jacob SE. Propylene Glycol in Contact Dermatitis: A Systematic Review. Dermatitis. 2018 Jan/Feb;29(1):6-12. doi: 10.1097/DER.0000000000000307. PMID: 29064881.

6. Jacob SE, Scheman A, McGowan MA. Propylene Glycol. Dermatitis. 2018 Jan/Feb;29(1):3-5. doi: 10.1097/DER.0000000000000315. PMID: 29059092.

7. Lalla SC, Nguyen H, Chaudhry H, Killian JM, Drage LA, Davis MDP, Yiannias JA, Hall MR. Patch Testing to Propylene Glycol: The Mayo Clinic Experience. Dermatitis. 2018 Jul/Aug;29(4):200-205. doi: 10.1097/DER.0000000000000393. PMID: 29923851.

8. Lessmann H, Schnuch A, Geier J, Uter W. Skin-sensitizing and irritant properties of propylene glycol. Contact Dermatitis. 2005 Nov;53(5):247-59. doi: 10.1111/j.0105-1873.2005.00693.x. PMID: 16283903.

9. Lowther A, McCormick T, Nedorost S. Systemic contact dermatitis from propylene glycol. Dermatitis. 2008 Mar-Apr;19(2):105-8. PMID: 18413114.