The parent compounds of acetaminophen (US market in 1955 in the US as Tylenol and other products) were first discovered in 1886 (acetanilide) and 1887 (phenacetin). These were the earliest synthetic fever Frontiers Potential adverse actions of prenatal exposure of acetaminophen to offspring Yes there is good evidence that acetaminophen (the active ingredient in Tylenol) can deplete glutathione under certain conditions. But whether that matters depends on dose, duration, and individual factors. Tylenol depletes glutathione levels