What Is Peg-55 Stearate?
Peg-55 Stearate is a synthetic ingredient created by combining stearic acid, a fatty acid usually taken from vegetable oils like coconut or palm, with about 55 units of ethylene oxide. This pairing gives the molecule a water-loving end and an oil-loving end, which is why it works so well in cleansers. The first polyethylene glycol stearates appeared in skin care in the late 1960s when chemists were looking for gentler ways to lift dirt and makeup without using harsh soap. Production starts with purified stearic acid that reacts with ethylene oxide in a controlled setting, forming a creamy white wax that is then blended into finished formulas. Today, Peg-55 Stearate shows up in facial cleansers, micellar waters, makeup removers, some lightweight lotions and even rinse-off masks where a mild yet effective cleansing boost is needed.
Peg-55 Stearate’s Cosmetic Benefits/Uses
Peg-55 Stearate serves one main purpose in cosmetics: cleansing. Its dual nature lets it surround oil, dirt and leftover makeup, mix them with water, then whisk them away when you rinse. This action helps products leave skin feeling clean and soft instead of tight or stripped of moisture.
Who Can Use Peg-55 Stearate
Peg-55 Stearate is gentle enough for most skin types. Oily and combination skin may enjoy its ability to lift away excess sebum without that squeaky tight feel. Normal skin can use it daily with little concern. Very dry or highly reactive skin should keep an eye on how their skin feels because any surfactant can sometimes steal a bit of moisture or cause mild irritation.
The stearic acid used today is typically sourced from coconut or palm oil which makes the ingredient suitable for vegans and vegetarians. If this matters to you check with the brand to confirm the fatty acid is plant derived as some older formulas can still rely on animal fat.
No specific warnings exist for pregnant or breastfeeding women when Peg-55 Stearate is used in rinse off or leave on products. It is considered a low risk ingredient but this is not medical advice and anyone who is pregnant or nursing should clear all skincare choices with their doctor just to be safe.
Peg-55 Stearate does not increase photosensitivity so it will not make skin more prone to sunburn. It also plays well with common actives like vitamin C or niacinamide and does not block the benefits of other ingredients in a routine.
Potential Side Effects/Adverse Reactions
Reactions to Peg-55 Stearate vary from person to person. The points below list possible side effects but most people will not notice any problems when the ingredient is used correctly in a finished product.
- Mild redness or stinging especially on very sensitive or broken skin
- Temporary dryness or tightness if the formula is left on the face too long or used too often
- Contact dermatitis in rare cases for those allergic to polyethylene glycol compounds
- Eye irritation if a cleanser containing Peg-55 Stearate is rubbed directly into the eyes without proper rinsing
- Increased penetration of other ingredients which could intensify the effect of stronger actives applied in the same routine
If you notice irritation or any other unwanted effect stop using the product and consult a healthcare professional
Comedogenic Rating
Rating: 1/5
Peg-55 Stearate is built on stearic acid, which on its own can sometimes clog pores, but the large polyethylene glycol chain makes the molecule far more water soluble and less likely to sit inside follicles. Finished formulas usually include it at low concentrations and in rinse off products, further lowering any pore blocking risk. Because of that it earns a near non-comedogenic score of 1. Most people prone to acne or breakouts can use it without trouble, although individual reactions always vary.
No data suggest it alters sebum production or encourages bacterial growth, so any blemishes that appear are more likely tied to other ingredients in the product or overall routine.
Summary
Peg-55 Stearate is a surfactant that lifts oil, dirt and makeup then binds them to water so they rinse away easily. This leaves skin feeling clean yet comfortable, making the ingredient handy in facial cleansers, micellar waters and lightweight lotions. It enjoyed steady but modest popularity since the 1970s, never a headline star yet a reliable backstage worker in many mainstream formulas. Regulatory reviews consider it low risk, with irritation or allergy appearing only rarely. As with any new skincare product, do a quick patch test before full use to be on the safe side.