Standard Adult Dosage for Pain or Fever
Adults typically take 325-650 mg every 4-6 hours as needed, not exceeding 4 grams per day. This applies to low-dose plain aspirin tablets for short-term relief.[1]
Daily Low-Dose Aspirin for Heart Health
For preventing heart attacks or strokes, the common dose is 81 mg (one baby aspirin) once daily. Doctors often recommend this long-term for those at high cardiovascular risk, but only under medical guidance.[1][2]
Children's Dosing by Age and Weight
Aspirin is rarely given to children under 16 due to Reye's syndrome risk. When used (e.g., for Kawasaki disease under supervision), dosing is weight-based: 10-15 mg/kg every 4-6 hours, max 80 mg/kg daily.[1][3]
Maximum Safe Frequency and Daily Limits
Do not take more often than every 4 hours or exceed 4 grams (4,000 mg) in 24 hours for adults. Frequency depends on formulation—enteric-coated or buffered versions follow the same intervals.[1]
Risks of Taking Too Often or High Doses
Frequent use raises stomach bleeding, ulcer, and kidney risks. Overuse can cause salicylate toxicity (ringing ears, nausea, rapid breathing). Long-term daily use without advice increases GI bleed odds by 50-60%.[2][4]
What If You Miss a Dose or Take Too Much
For daily heart regimens, skip missed doses—don't double up. Overdose requires immediate medical help; symptoms start at 150 mg/kg. Activated charcoal or dialysis may be used in severe cases.[1][3]
Differences for Extended-Release Aspirin
Extended-release forms (e.g., 162.5 mg) are taken once or twice daily for cardio protection, not more frequently due to slower absorption.[1]
When to Talk to a Doctor Before Regular Use
Consult for pregnancy (avoid third trimester), asthma, ulcers, bleeding disorders, or with drugs like ibuprofen/warfarin. Age 60+ or alcohol use heightens risks.[2][4]
[1]: FDA Aspirin Label
[2]: USPSTF Aspirin Guidelines
[3]: Medscape Aspirin Dosing
[4]: Mayo Clinic Aspirin Risks