Ingredient review
PEG-75 Beta-Sitosterol
INCI: PEG-75 Beta-Sitosterol
A gentle, water-soluble emulsifier derived from plant sterols that helps blend oil and water phases in skincare, with mild skin-conditioning benefits.
In plain English
PEG-75 Beta-Sitosterol is a semi-synthetic ingredient made by attaching a water-loving PEG chain to beta-sitosterol, a natural plant sterol found in soy and other plants. This makes the normally oil-soluble sterol water-soluble, allowing it to act as an emulsifier that helps mix oil and water in creams and lotions. It also provides mild skin conditioning, leaving skin feeling smooth without being greasy. It is considered very gentle and non-irritating, making it suitable for sensitive skin.
Review score
Safety, usefulness, and evidence
Potentially useful with some tradeoffs
The evidence base is useful, but some claims depend heavily on the formula.
Risk flags are low for most users, though the finished product can still irritate.
- Source
- semi synthetic
- Evidence
- moderate
- Irritation
- low
- Clogging risk
- low
Quick decision guide
Useful, but context matters
PEG-75 Beta-Sitosterol is generally a lower-concern ingredient when the full formula suits your skin.
Plain-English read
Treat this as a practical screening step before you compare products that contain this ingredient.
- Step 1Start with the score, then check the irritation and clogging risk before judging PEG-75 Beta-Sitosterol.
- Step 2Use the "Best for" and "Use caution if" sections to match the ingredient to your skin, not just to a marketing claim.
- Step 3If a product stings, breaks you out, or worsens irritation, judge the finished formula and stop using it even if the ingredient scores well.
Score terms in plain English
Irritation risk
lowLess likely to sting, burn, or bother most users, though sensitive skin can still react.
Clogging risk
lowLess likely to feel heavy or contribute to clogged pores for most skin types.
Evidence level
moderateThere is useful support, but formula details and claim strength still matter.
What it is
A semi-synthetic compound created by reacting beta-sitosterol (a plant sterol) with polyethylene glycol (PEG-75). The PEG chain makes the sterol water-soluble, enabling it to function as a non-ionic emulsifier and skin-conditioning agent.
How it works
In a cosmetic formula, PEG-75 Beta-Sitosterol sits at the interface between oil and water droplets, reducing surface tension and allowing them to mix into a stable emulsion. It also deposits a thin, non-occlusive film on the skin, which helps retain moisture and gives a smooth feel.
Pros
Gentle emulsifier
Helps blend oil and water into a stable, creamy texture without the irritation common with some other emulsifiers, making it ideal for sensitive-skin formulations.
Mild skin conditioning
Leaves skin feeling smooth and soft without a heavy or greasy residue, enhancing the sensory experience of moisturizers and serums.
Cons and cautions
Soy-derived source
Derived from soy sterols, which may be a concern for those with soy allergies, though the processing likely removes allergenic proteins.
PEG-related purity concerns
As a PEG compound, there is a theoretical risk of trace impurities like 1,4-dioxane, but cosmetic-grade ingredients are purified to safe levels.
Best for
- People with dry or normal skin looking for a gentle emulsifier in moisturizers
- Those with sensitive skin who need low-irritation formulas
Use caution if
- Individuals with confirmed soy allergy who prefer to avoid any soy-derived ingredients (though risk is minimal due to processing)
Usage tips
Safety summary
PEG-75 Beta-Sitosterol is considered safe for use in cosmetics at typical concentrations. It has low irritation and comedogenic potential. The main safety consideration is the potential for trace impurities in PEG compounds, but cosmetic-grade ingredients are purified to meet safety standards. The soy source is highly processed, making allergic reactions unlikely.
Research notes
Beta-sitosterol itself has been studied for anti-inflammatory and skin-barrier benefits, but specific research on PEG-75 Beta-Sitosterol is limited. Its safety as a cosmetic ingredient is supported by industry use and regulatory acceptance. The PEG chain is well-studied and considered safe in cosmetic applications.
Common label clues
- Typical concentration
- 0.5% to 5%
- Regulatory status
- Approved for use in cosmetics in the US (FDA) and EU (CosIng) with no concentration restrictions, though typical use is under 5%.
- Common uses
- Moisturizers, Serums, Cleansers, Sunscreens
- Environmental note
- The PEG chain is biodegradable, and the plant sterol is renewable, giving this ingredient a relatively low environmental impact compared to fully synthetic emulsifiers.
Good to know
- PEG-75 Beta-Sitosterol is often used in 'natural' or 'plant-based' formulations because the sterol is derived from plants
- It is considered biodegradable and has a favorable environmental profile compared to some synthetic emulsifiers
Common questions
What is PEG-75 Beta-Sitosterol in beauty products?
PEG-75 Beta-Sitosterol is a semi-synthetic ingredient made by attaching a water-loving PEG chain to beta-sitosterol, a natural plant sterol found in soy and other plants. This makes the normally oil-soluble sterol water-soluble, allowing it to act as an emulsifier that helps mix oil and water in creams and lotions. It also provides mild skin conditioning, leaving skin feeling smooth without being greasy. It is considered very gentle and non-irritating, making it suitable for sensitive skin.
What does PEG-75 Beta-Sitosterol do in a beauty product?
In a cosmetic formula, PEG-75 Beta-Sitosterol sits at the interface between oil and water droplets, reducing surface tension and allowing them to mix into a stable emulsion. It also deposits a thin, non-occlusive film on the skin, which helps retain moisture and gives a smooth feel.
Is PEG-75 Beta-Sitosterol safe for most people?
PEG-75 Beta-Sitosterol is considered safe for use in cosmetics at typical concentrations. It has low irritation and comedogenic potential. The main safety consideration is the potential for trace impurities in PEG compounds, but cosmetic-grade ingredients are purified to meet safety standards. The soy source is highly processed, making allergic reactions unlikely.
Who should be careful with PEG-75 Beta-Sitosterol?
Individuals with confirmed soy allergy who prefer to avoid any soy-derived ingredients (though risk is minimal due to processing)
Research sources
Ingredient reviews are educational and are not medical advice. Patch test new products and ask a licensed clinician about persistent irritation, allergies, pregnancy-specific questions, or diagnosed skin conditions.