What Is Bis-(Methyl Epoxidized Soyate) Peg-20?
Bis-(Methyl Epoxidized Soyate) PEG-20 is a plant-derived ingredient made by linking a portion of polyethylene glycol with methyl epoxidized soyate, a modified form of soybean oil. The soybean oil provides a renewable base while the PEG-20 section adds water-loving properties, giving the final molecule both oil-friendly and water-friendly ends. This “two-sided” nature lets it sit at the border of oil and water, which is why formulators reach for it when they need to mix the two.
Soy-based surfactants first gained attention in the 1990s as brands looked for gentler and more eco-conscious options than petroleum surfactants. Over time chemists learned to epoxidize (add an oxygen ring) to the soyate portion, then cap it with PEG-20, boosting its ability to lift dirt and oil without harshness. Today the ingredient is produced in large batches: soybean oil is methylated, epoxidized to introduce reactive oxygen rings, then joined to PEG-20 under controlled heat and catalysts. The result is a clear to pale yellow liquid that dissolves easily in water.
You’ll most often see Bis-(Methyl Epoxidized Soyate) PEG-20 in facial cleansers, body washes, shampoos, micellar waters, makeup removers, exfoliating scrubs, sheet mask essences and bath foams. It is valued for mild cleansing, a soft creamy lather and the ability to keep oils, fragrances and active ingredients evenly spread throughout a formula.
Bis-(Methyl Epoxidized Soyate) Peg-20’s Cosmetic Benefits/Uses
This multitasking helper supports several roles in modern skin and hair care formulas:
- Cleansing – loosens and lifts away excess oil dirt and makeup without stripping skin or hair
- Dispersing – helps pigments exfoliating beads and other particles spread evenly so every pump or scoop delivers the same mix
- Emulsifying – binds oil and water phases letting brands create smooth stable creams lotions and gels without separation
- Foam Boosting – heightens and stabilizes lather giving washes a rich cushiony feel that rinses clean
- Hydrotrope – improves the solubility of otherwise tricky fragrance oils or actives allowing higher loads without cloudiness
Who Can Use Bis-(Methyl Epoxidized Soyate) Peg-20
This soy based surfactant is generally considered friendly for all skin types including dry, normal, oily, combination and sensitive skin thanks to its mild cleansing profile and balanced oil-to-water affinity. People with extremely oily skin may find it works best in tandem with deeper cleansers rather than as the sole surfactant, while those with very dry or compromised skin appreciate its gentle action that does not strip the barrier.
Because it is derived from soybean oil and synthesized with polyethylene glycol both of which are plant sourced and not animal tested, Bis-(Methyl Epoxidized Soyate) PEG-20 is suitable for vegans and vegetarians.
No reproductive or developmental hazards have been linked to topical use of this ingredient at cosmetic concentrations. That said pregnant or breastfeeding individuals should always show any leave-on or rinse-off product to their health care provider before regular use as personal circumstances may differ. This content is informational only and not medical advice.
The molecule does not absorb UV light or alter the skin’s sun response so it is not known to cause photosensitivity. It is also biodegradable and free of common sensitizers like fragrance allergens which makes it a low concern option for daily cleansing formulas.
Potential Side Effects/Adverse Reactions
Side effects and reactions to the topical application of Bis-(Methyl Epoxidized Soyate) Peg-20 can vary from person to person. The points below outline potential issues yet most users will not encounter them when the ingredient is used correctly in a well formulated product.
- Mild transient skin irritation – slight redness or stinging may occur on very sensitive or compromised skin especially with high concentrations
- Contact dermatitis in individuals with soy allergy – although the protein content is minimal trace residues could trigger a reaction in highly sensitized users
- Eye irritation – if the product is splashed directly into the eyes temporary burning or watering can happen until rinsed out fully
- Dryness with overuse – excessive cleansing or leaving a rinse-off product on the skin for prolonged periods may disrupt natural lipids leading to tightness or flaking
- Enhanced penetration of other actives – as a hydrotrope it can increase the solubility of certain ingredients which in turn might boost their absorption and potential irritation
If any discomfort, persistent redness or swelling develops while using Bis-(Methyl Epoxidized Soyate) Peg-20 stop application immediately and seek advice from a qualified medical professional.
Comedogenic Rating
Rating: 1/5
Although Bis-(Methyl Epoxidized Soyate) Peg-20 starts from soybean oil its structure is heavily modified and ends up water soluble. Water-soluble surfactants are unlikely to sit in pores long enough to form plugs. Most finished products also rinse away, further lowering the risk. Because of these factors it earns a very low score of 1.
That low score means it is generally fine for people who are prone to acne or frequent breakouts.
One extra note: if the formula pairs this ingredient with heavy oils or waxes the overall product could still feel rich, so always consider the full ingredient list when judging pore-clogging potential.
Summary
Bis-(Methyl Epoxidized Soyate) Peg-20 works as a gentle cleanser, dispersant, emulsifier, foam booster and hydrotrope. Its split personality—oil loving on one side and water loving on the other—lets it pull grime away, keep oils and actives evenly mixed and build a soft cushion of lather that rinses clean.
It is not as famous as classic sulfates or coco-glucosides yet formulators who need a mild plant-based helper reach for it in micellar waters, sheet masks and sulfate-free washes.
Safety reviews rate it low risk for irritation and the molecule is biodegradable. Still every skin type is different so do a quick patch test when trying any new product that contains this ingredient.