You should use a little less than a teaspoon. Acetaminophen (tylenol) starts taking effect within 45 to 60 minutes and should last four hours. If it wears- off too soon, then use a dose of Ibuprofen.
Nonsteroidal anti-inflammatory drugs, usually abbreviated to NSAIDs // EN-sed—but also referred to as nonsteroidal anti-inflammatory agents/analgesics (NSAIAs) or nonsteroidal anti-inflammatory medicines (NSAIMs)—are a class of drugs that provide analgesic and antipyretic (fever-reducing) effects, and, in higher doses, anti-inflammatory effects.
The term nonsteroidal distinguishes these drugs from steroids, which, among a broad range of other effects, have a similar eicosanoid-depressing, anti-inflammatory action. As analgesics, NSAIDs are unusual in that they are non-narcotic and thus are used as a non-addictive alternative to narcotics. Tylenol