thimerosal

Thimerosal is an organomercury compound used primarily as a preservative in vaccines and other biological and pharmaceutical products to prevent the growth of bacteria and fungi. Developed in 1927, it has been widely used since the 1930s. Thimerosal is approximately 50% mercury by weight and is metabolized into ethylmercury and thiosalicylate. Its mechanism of action involves inhibiting sulfhydryl-containing active sites of various enzymes by binding to sulfhydryl compounds such as glutathione, cysteine, and protein groups. Additionally, it can activate the InsP3 calcium channel on endoplasmic reticular membranes, triggering intracellular calcium release that may affect cellular functions dependent on calcium signaling. While its use has been reduced or eliminated from most vaccines in many countries due to safety concerns—despite scientific consensus supporting its safety at low doses—it remains present in some multi-dose vials of influenza vaccine and other products[1][2][3][5].

Brand names

Merthiolate

Other names

thimerosalthiomersalmerthiolate