slide 2 of 12. Skin The skin is the largest organ in the human body. Its main job is to maintain the body's temperature, which means that sweat is created to cool the body, and goosebumps or raised hair occur to trap heat in the body. Along with sweat glands, the skin contains oil glands.
...However, if I am wrong about that, the answer is that acetaminophen (and its metabolites) are identifiable for up to 48 hours after you took the pill. Less if you took tiny doses, but up to standard clinical doses (<8g), it's 48ish hours.
If an assay cannot be obtained or if the acetaminophen level is clearly in the toxic range (ie, above the treatment line on the treatment nomogram), dosing with acetylcysteine should be initiated and continued for the full course of therapy.cetylcysteine may have a role in the management of patients who present more than 24 hours after an acetaminophen overdose. Evidence suggests that acetylcysteine treatment may improve survival in patients presenting late and may be appropriate almost any time after overdose ingestion.