Ingredient review
PEG-1182 Methyl Ester Sericin
INCI: PEG-1182 METHYL ESTER SERICIN
A modified silk protein that forms a lightweight film on skin, offering temporary smoothing and moisture retention, but with limited independent research on this specific PEGylated form.
In plain English
This ingredient is a silk protein (sericin) that has been chemically modified with a large PEG (polyethylene glycol) chain. In skincare, it spreads easily and dries down to a very thin, flexible film on the skin's surface. This film helps hold moisture close to the skin and can make the skin feel smoother and softer temporarily. The PEG part also helps the ingredient dissolve in water-based formulas. Think of it as a gentle, modern version of the silk proteins used in traditional Asian beauty rituals, but engineered to be more stable and easier to formulate with.
Review score
Safety, usefulness, and evidence
Potentially useful with some tradeoffs
The evidence base is still emerging, so marketing claims deserve extra caution.
Risk flags are low for most users, though the finished product can still irritate.
- Source
- semi synthetic
- Evidence
- emerging
- Irritation
- low
- Clogging risk
- low
Quick decision guide
Useful, but context matters
PEG-1182 Methyl Ester Sericin 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-1182 Methyl Ester Sericin.
- 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
emergingThe ingredient may be promising, but claims should be treated more cautiously.
What it is
PEG-1182 Methyl Ester Sericin is a semi-synthetic ingredient created by attaching a very large polyethylene glycol (PEG) chain (with 1182 repeating units) to sericin, a protein derived from silk. The PEG modification makes the sericin water-soluble and helps it form a uniform film on skin.
How it works
When applied to the skin, the sericin portion binds to the skin's surface, while the PEG chain helps the molecule spread evenly. As the water evaporates, the ingredient forms a thin, flexible film that physically reduces water loss from the skin (transepidermal water loss, or TEWL). This film also provides a temporary smoothing effect by filling in fine surface irregularities. The sericin component may also offer some antioxidant activity, though this is less studied in the modified form.
Pros
Lightweight film
Creates a thin, flexible barrier that helps lock in moisture without feeling heavy or sticky, making it suitable for layering under makeup or sunscreen.
Smoothing effect
Temporarily fills in fine lines and uneven texture, giving skin a smoother appearance that can improve the look of makeup application.
Cons and cautions
Limited research
Most studies on sericin focus on the natural protein, not this PEG-modified version. The specific benefits and long-term effects of PEG-1182 Methyl Ester Sericin are not well-documented in peer-reviewed literature.
PEG purity concerns
As with any PEGylated ingredient, there is a potential for trace impurities if manufacturing standards are not high. Reputable brands typically use purified grades, but it's something to be aware of.
Best for
- People with normal to dry skin looking for extra moisture retention
- Those who enjoy lightweight, non-greasy skin feel in their serums or moisturizers
Use caution if
- Individuals with known sensitivity to silk proteins or PEG compounds should patch test first
Usage tips
Safety summary
PEG-1182 Methyl Ester Sericin is considered low-risk for irritation and comedogenicity based on its large molecular size and the generally mild profile of sericin. The main safety consideration is the potential for trace impurities in PEG manufacturing, which is managed by reputable suppliers through purification. Patch testing is recommended for those with sensitive skin or known allergies to silk or PEG compounds.
Research notes
Direct studies on PEG-1182 Methyl Ester Sericin are scarce. The ingredient's proposed benefits are extrapolated from research on natural sericin, which has shown moisturizing, film-forming, and antioxidant properties in vitro and in small human studies. The PEG modification is primarily for formulation compatibility and does not necessarily enhance the bioactivity of sericin. More research is needed to confirm the specific performance and safety of this modified form.
Common label clues
- Typical concentration
- 0.5% to 3% in leave-on products
- Regulatory status
- Generally recognized as safe for use in cosmetics when formulated according to good manufacturing practices. The FDA does not specifically approve cosmetic ingredients but regulates them under the Federal Food, Drug, and Cosmetic Act. In the EU, it is listed in the CosIng database as a film-forming agent.
- Common uses
- Serums, Moisturizers, Leave-on treatments, Hair conditioners
- Environmental note
- PEG compounds are synthetic and may not be readily biodegradable. The environmental impact of large PEG molecules like this one is not well-studied, but they are not typically associated with significant ecotoxicity at the low concentrations used in cosmetics.
Good to know
- Sericin is a protein found in silk cocoons; it is often removed during silk processing but is valued in cosmetics for its moisturizing properties.
- The 'PEG-1182' designation refers to the average number of ethylene glycol units, making this a very large PEG molecule, which is less likely to penetrate the skin than smaller PEGs.
Common questions
What is PEG-1182 Methyl Ester Sericin in beauty products?
This ingredient is a silk protein (sericin) that has been chemically modified with a large PEG (polyethylene glycol) chain. In skincare, it spreads easily and dries down to a very thin, flexible film on the skin's surface. This film helps hold moisture close to the skin and can make the skin feel smoother and softer temporarily. The PEG part also helps the ingredient dissolve in water-based formulas. Think of it as a gentle, modern version of the silk proteins used in traditional Asian beauty rituals, but engineered to be more stable and easier to formulate with.
What does PEG-1182 Methyl Ester Sericin do in a beauty product?
When applied to the skin, the sericin portion binds to the skin's surface, while the PEG chain helps the molecule spread evenly. As the water evaporates, the ingredient forms a thin, flexible film that physically reduces water loss from the skin (transepidermal water loss, or TEWL). This film also provides a temporary smoothing effect by filling in fine surface irregularities. The sericin component may also offer some antioxidant activity, though this is less studied in the modified form.
Is PEG-1182 Methyl Ester Sericin safe for most people?
PEG-1182 Methyl Ester Sericin is considered low-risk for irritation and comedogenicity based on its large molecular size and the generally mild profile of sericin. The main safety consideration is the potential for trace impurities in PEG manufacturing, which is managed by reputable suppliers through purification. Patch testing is recommended for those with sensitive skin or known allergies to silk or PEG compounds.
Who should be careful with PEG-1182 Methyl Ester Sericin?
Individuals with known sensitivity to silk proteins or PEG compounds should patch test first
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.