What to do if i have a headache, and i only have junior strength motrin to take. the expiration date says: jn11.?

Acetaminophen first: Acetaminophen 650 mg is always a safe bet to try first for a headache. If there is no response within an hour, Ibuprofen 400-600 mg can be used. Expired medications can be used but pill efficacy &safety cannot be guaranteed. Except for tetracycline, liquid antibiotics &refrigerated medications like insulin, there is probably little if any lost effect as a per a fda study of military stockpiles.