17-Alpha-Ethynylestradiol is a synthetic hormone from birth control pills. It enters water via human waste and can disrupt endocrine systems in aquatic life and humans.

17-Alpha-Ethynylestradiol is a potent synthetic estrogen widely used in oral contraceptives. It enters water systems primarily through human excretion and improper disposal of medications. Conventional wastewater treatment plants struggle to remove this compound effectively. Even at extremely low concentrations, it can cause significant reproductive disruptions in fish and other aquatic organisms. While human health impacts are still being studied, there's growing concern about its potential long-term effects on endocrine systems and reproductive health.