Does the antimony in polyester clothing mimic estrogen?

Antimony trioxide is a catalyst used in the production of polyester fiber, and residual amounts remain in the finished fabric. Research has identified antimony as an estrogenic compound, meaning it can bind to estrogen receptors in the body and mimic the effects of natural estrogen. This is particularly concerning for reproductive health because even small disruptions to estrogen signaling can affect ovulation, sperm production, and embryo development.

Antimony leaches from polyester fabrics through perspiration, and the rate of leaching increases with heat, moisture, and prolonged skin contact. During exercise, when body temperature rises and sweating is heavy, antimony release from activewear intensifies. Studies have detected antimony in human blood and urine at levels that correlate with synthetic textile exposure, confirming that clothing is a meaningful route of absorption for this metal.

Because antimony is intrinsic to polyester production, there is no way to manufacture antimony-free polyester at scale. The only reliable way to avoid this exposure is to choose non-polyester fabrics. Plant-based performance fabrics like Tencel and organic cotton provide comparable comfort and moisture management without introducing estrogenic metals into your body. ONDU features brands like Tripulse and Reprise Activewear that demonstrate polyester-free alternatives can perform just as well.