**For a healthy adult, the general limits are:**
- **4,000 mg (4 grams) per day** — the long-standing maximum in FDA labeling and clinical references
- **3,000 mg per day** — the more conservative limit now printed on many U.S. Extra Strength Tylenol packages (Regular Strength lists 3,250 mg)
**Typical dosing:** 325–650 mg every 4–6 hours, or 1,000 mg every 6–8 hours, staying under the daily total.
**Important cautions:**
- **Watch for hidden acetaminophen.** It's in hundreds of combination products — cold/flu remedies, sleep aids, and prescription opioids (e.g., Percocet, Vicodin, Norco). Accidental doubling-up is the most common route to overdose.
- **Lower limits apply** if you have liver disease, drink alcohol regularly (roughly 3+ drinks/day), are malnourished or fasting, weigh under ~50 kg, or take acetaminophen daily for long stretches. In these cases **2,000 mg/day or less** is often recommended — and some people should avoid it entirely.
- **Overdose is serious but deceptive.** Liver injury can occur with few early symptoms, and the antidote works best within 8 hours. If you suspect an overdose, contact Poison Control (1-800-222-1222 in the U.S.) or seek emergency care immediately — don't wait for symptoms.
If you're taking it regularly, or take other medications, it's worth checking with a pharmacist or your doctor about what's safe for your situation.