Methylparaben on your skin: a safety profile
Moderate riskDermal application is the primary exposure route for methylparaben and accounts for the majority of human systemic exposure. Methylparaben penetrates intact skin; absorption efficiency varies by formulation (leave-on products such as moisturizers and sunscreens produce higher systemic exposure than rinse-off products such as shampoos). Studies of dermal absorption find that intact methylparaben (the estrogenically active form) enters the bloodstream; in the gut it would be hydrolyzed, but dermally absorbed methylparaben is not similarly deactivated before reaching systemic circulation. Urinary methylparaben concentrations in NHANES reflect primarily dermal absorption from cosmetics rather than dietary intake. Nail salon workers using methylparaben-containing nail products have elevated occupational exposures. The safety margin between typical consumer dermal exposure and doses causing estrogenic effects in animal studies is considered adequate by most regulatory bodies, but this margin narrows when multiple paraben-containing products are used simultaneously.
What is methylparaben?
The IUPAC name is methyl 4-hydroxybenzoate.
Also known as: methyl 4-hydroxybenzoate, Methyl paraben, Methyl p-hydroxybenzoate, Nipagin.
- IUPAC name
- methyl 4-hydroxybenzoate
- CAS number
- 99-76-3
- Molecular formula
- C8H8O3
- Molecular weight
- 152.15 g/mol
- SMILES
- COC(=O)C1=CC=C(C=C1)O
- PubChem CID
- 7456
Risk for people
Moderate riskDermal application is the primary exposure route for methylparaben and accounts for the majority of human systemic exposure. Methylparaben penetrates intact skin; absorption efficiency varies by formulation (leave-on products such as moisturizers and sunscreens produce higher systemic exposure than rinse-off products such as shampoos). Studies of dermal absorption find that intact methylparaben (the estrogenically active form) enters the bloodstream; in the gut it would be hydrolyzed, but dermally absorbed methylparaben is not similarly deactivated before reaching systemic circulation. Urinary methylparaben concentrations in NHANES reflect primarily dermal absorption from cosmetics rather than dietary intake. Nail salon workers using methylparaben-containing nail products have elevated occupational exposures. The safety margin between typical consumer dermal exposure and doses causing estrogenic effects in animal studies is considered adequate by most regulatory bodies, but this margin narrows when multiple paraben-containing products are used simultaneously.
Regulatory consensus
8 regulatory and scientific bodies have classified Methylparaben. The classifications differ — that's the data.
| Agency | Year | Classification | Notes |
|---|---|---|---|
| IARC | — | Group 3 | |
| EPA CTX / Genetox | — | Genotoxicity: positive (Ames: positive, 7 positive / 9 negative reports) | |
| EPA CTX / Genetox | — | Genotoxicity: positive (Ames: positive, 7 positive / 9 negative reports) | |
| EPA CTX / Skin-Eye | — | Skin Irritation: Not classified (score: low) | |
| EPA CTX / Skin-Eye | — | Eye Irritation: Category 6.4A (Category 2A) (score: high) | |
| EPA CTX / Skin-Eye | — | Skin Irritation: Category 6.3B (Category 3) (score: moderate) | |
| EPA CTX / Skin-Eye | — | Skin Sensitization: Category 6.5B (Category 1) (score: moderate) | |
| EPA CTX / Skin-Eye | — | skin sensitisation: in vivo (non-LLNA): Not likely to be sensitizing (score: low) |
Regulators apply different standards of evidence — animal-data weighting, exposure-pattern assumptions, epidemiological power thresholds — which is why two scientific bodies can review the same data and reach different conclusions. The disagreement is the data.
Where you encounter methylparaben
- Industrial Facilities — Manufacturing plants, Chemical storage areas, Waste treatment sites
- Occupational Environments — Factories, Warehouses, Transportation vehicles
- Personal Care — shampoo, conditioner, lotion, cosmetics, sunscreen
Safer alternatives
Lower-risk approaches that achieve a similar outcome to Methylparaben:
-
Physical/mechanical pest control (IPM)
Trade-offs: More labor-intensive. May not be sufficient for severe infestations.Relative cost: 1.2-2×
Frequently asked questions
Is methylparaben safe for you?
Dermal application is the primary exposure route for methylparaben and accounts for the majority of human systemic exposure. Methylparaben penetrates intact skin; absorption efficiency varies by formulation (leave-on products such as moisturizers and sunscreens produce higher systemic exposure than rinse-off products such as shampoos). Studies of dermal absorption find that intact methylparaben (the estrogenically active form) enters the bloodstream; in the gut it would be hydrolyzed, but dermally absorbed methylparaben is not similarly deactivated before reaching systemic circulation. Urinary methylparaben concentrations in NHANES reflect primarily dermal absorption from cosmetics rather than dietary intake. Nail salon workers using methylparaben-containing nail products have elevated occupational exposures. The safety margin between typical consumer dermal exposure and doses causing estrogenic effects in animal studies is considered adequate by most regulatory bodies, but this margin narrows when multiple paraben-containing products are used simultaneously.
What products contain methylparaben?
Methylparaben appears in: Manufacturing plants (Industrial facilities); Chemical storage areas (Industrial facilities); Factories (Occupational environments); Warehouses (Occupational environments); shampoo (Personal care).
Why do regulators disagree about methylparaben?
Methylparaben has been classified by 8 agencies including IARC, EPA CTX / Genetox, EPA CTX / Genetox, EPA CTX / Skin-Eye, EPA CTX / Skin-Eye, with differing conclusions. Regulators apply different standards of evidence (animal data weighting, exposure-pattern assumptions, epidemiological power thresholds), which is why two scientific bodies can review the same data and reach different conclusions. See the regulatory consensus table on this page for the full picture.
See Methylparaben in the body app
Look up products containing methylparaben, compare to alternatives, and explore the full data record.
Open in body View raw API dataSources (3)
- EU Scientific Committee on Consumer Safety (SCCS): Opinion on Parabens (Methylparaben, Ethylparaben, Propylparaben, Butylparaben) in Cosmetics (2021) — regulatory
- IARC Monographs Volume 101: Methylparaben — Group 3 Evaluation (Not Classifiable as to Carcinogenicity in Humans) (2013) — regulatory
- US FDA: Parabens in Cosmetics — Safety Assessment and Consumer Information Update (2023) — regulatory
Reference data, not professional advice. Aggregates publicly available regulatory and scientific data; not a substitute for veterinary, medical, legal, or regulatory advice. Why we built ALETHEIA →