What Is Peg-23M?
Peg-23M is a large molecular weight form of polyethylene glycol made by linking about 23,000 units of ethylene oxide to create a long, water-loving chain. The process starts with ethylene oxide gas, which reacts with water under controlled heat and pressure to build up the polymer. Manufacturers then purify and dry the material into a waxy or flake-like solid that dissolves easily in water.
Polyethylene glycols have been around since the 1940s and quickly found favor with cosmetic chemists because they mix well with both water and oil. Peg-23M entered personal care formulas as thicker textures and more stable emulsions became popular in the 1980s. Its high molecular weight gives brands a way to boost thickness without using heavy waxes or fats that can feel greasy.
Today you will spot Peg-23M in rinse-off masks, hydrating creams, lotions, hair conditioners, styling gels, make-up removers, sunscreens and soothing after-sun products. It often works behind the scenes to keep a formula smooth, stable and pleasant to spread.
Peg-23M’s Cosmetic Benefits/Uses
Formulators choose Peg-23M for several practical reasons that improve both the product and the user experience:
- Binding – Helps hold solid particles such as clays, pigments or exfoliating beads evenly throughout a formula so each scoop or pump delivers consistent results
- Emulsion Stabilising – Keeps oil and water phases blended over time which prevents separation and extends shelf life even when the product sits on a bathroom shelf or travels in a bag
- Viscosity Controlling – Thickens watery mixtures into creamy lotions or gels giving them a richer feel and reducing runny drips during application
Who Can Use Peg-23M
Peg-23M is considered gentle enough for most skin types including dry, normal, combination, oily and sensitive. Its large molecular size keeps it on the surface so it rarely penetrates or upsets the skin’s natural barrier. Those with very reactive or allergy-prone skin should still check the full ingredient list since the rest of the formula may contain triggers.
The ingredient is synthetically produced from petrochemical feedstocks, not animal sources, so products using Peg-23M are generally suitable for vegans and vegetarians.
Current research does not flag Peg-23M as a risk during pregnancy or breastfeeding. The polymer is too big to enter the bloodstream through intact skin. This is not medical advice and anyone who is pregnant or nursing should ask a healthcare professional before starting a new skincare product.
Peg-23M does not make skin more sensitive to sunlight and it does not interfere with common actives such as vitamin C or retinoids, so daily routines and sunscreen habits can stay the same.
Potential Side Effects/Adverse Reactions
People can respond differently to any cosmetic ingredient so the points below list potential side effects of topical Peg-23M. When the ingredient is used correctly most users will not notice any of these issues.
- Mild redness or stinging in very sensitive skin, especially if the formula contains high levels of fragrance or acids
- Contact dermatitis in rare cases where someone is allergic to polyethylene glycols
- Dry or tight feeling if the product is left on skin for long periods without additional moisturizers
- Pore clogging is unlikely but can occur if Peg-23M is combined with heavy oils in the same product and not rinsed off
- Impurity concerns such as traces of 1,4-dioxane from manufacturing are controlled by reputable brands yet can cause worry for some users
If you notice persistent irritation, stop using the product and seek advice from a medical professional or dermatologist.
Comedogenic Rating
Rating: 0 / 5 – Peg-23M is highly water soluble, has a very large molecular size and does not sit inside pores so it is classed as non-comedogenic. It is commonly used to thin out or stabilise formulas rather than coat the skin with an occlusive film, which further lowers the risk of clogging. Suitable for those who are prone to acne or breakouts.
Because Peg-23M is usually paired with lightweight oils or found in rinse-off treatments, the chance of residue building up on skin is minimal. As always, the overall formula and a person’s cleansing habits will influence breakouts more than this single ingredient.
Summary
Peg-23M is a high-molecular polyethylene glycol that binds particles, stabilises oil-in-water emulsions and controls viscosity to create smoother thicker textures. It achieves this by forming a flexible water-loving network around droplets and solids, preventing separation and adding body without greasiness.
While not the trendiest star active, this polymer remains a quiet workhorse in many lotions, gels and conditioners thanks to its reliability ease of use and vegan origin. Studies and decades of use show a strong safety profile with only rare irritation or allergy reports.
Most people can use products containing Peg-23M with confidence but patch testing any new formula is always a smart step for catching individual sensitivities early.