Methylparaben is a member of the paraben family, a group of compounds that possess antibacterial and antifungal properties. These agents are esters of para-hydroxybenzoic acid, which is why they are collectively called parabens. However, in contrast to its cousins, ethylparaben, butylparaben, and propylparaben, methylparaben receives its specific name owing to the fact that its chemical structure contains the methyl alkyl group. Methylparaben is found in several fruits, in particular blueberries, where it acts as an antimicrobial agent.
Methylparaben is an anti-fungal agent often used in a variety of cosmetics and personal-care products. Methylparaben is commonly used as a fungicide in Drosophila food media. Usage of methylparaben is toxic at higher concentrations, has an estrogenic effect and slow Drosophila growth rate in the larval and pupal stages at a lower concentrations. Methylparaben is produced naturally and found in several fruits, primarily blueberries, along with other parabens. There is controversy about whether methylparaben or propylparabens are harmful at concentrations typically used in body care or cosmetics.
Some studies of breast tumors show a build up of methylparabens in the breast tissue. Methyparaben is also estrogenic. Methylparaben and propylparaben are considered generally recognized as safe (GRAS) for food and cosmetic antibacterial preservation. Methylparaben is readily metabolized by common soil bacteria, making it completely biodegradable. Methylparaben is readily absorbed from the gastrointestinal tract or through the skin. It is hydrolyzed to p-hydroxybenzoic acid and rapidly excreted in urine without accumulating in the body.
Acute toxicity studies have shown that methylparaben is practically non-toxic by both oral and parenteral administration in animals. In a population with normal skin, methylparaben is practically non-irritating and non-sensitizing; however, allergic reactions to ingested parabens have been reported. Methylparaben is not carcinogenic, mutagenic, teratogenic or embryotoxic; in addition, it is negative in the uterotrophic assay. Studies indicate that methylparaben applied on the skin may react with UVB, leading to increased skin aging and DNA damage.