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 The FDA is signaling that perhaps immediate treatment with acetaminophen is less clearly needed for a low grade fever, especially in pregnancy, unless theres a stronger indication for it., Safer Tylenol's Impact on Glutathione and Liver Damage 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 And Alcohol: Dangers, Safe Alternatives & Treatment