Mefenamic Acid — What It Is and When to Use It

Mefenamic acid is an NSAID commonly used for short-term pain relief, especially menstrual cramps (dysmenorrhea), mild-to-moderate pain after dental work, and other acute pains. It reduces inflammation and blocks pain signals, so it works faster than some other options for cramps. Use it only as recommended by your doctor — it’s not meant for long-term daily use like some chronic pain meds.

How to Take Mefenamic Acid Safely

Typical adult dosing starts with a 500 mg loading dose, then 250 mg every 6 hours as needed. Most guidelines cap total daily intake at 1,000 mg. For menstrual pain, people often take it at the first sign of cramps and continue for 2–3 days. Take pills with food or milk to cut down on stomach upset. Don’t exceed the prescribed dose and avoid using it continuously for weeks without medical review.

Certain people should avoid mefenamic acid: if you have active peptic ulcer disease, bleeding disorders, severe heart, liver or kidney disease, or a known allergy to NSAIDs. It’s also not recommended in the third trimester of pregnancy because it can affect the baby’s circulation. If you have asthma that reacts to NSAIDs, steer clear — mefenamic can trigger bronchospasm in sensitive people.

Side Effects and Drug Interactions

Common side effects include stomach pain, nausea, diarrhea, headache, dizziness, and skin rash. Less common but serious problems are gastrointestinal bleeding, high blood pressure, kidney or liver issues, and changes in blood counts. Stop the drug and contact a doctor if you notice bloody stools, severe abdominal pain, yellowing of skin, or marked swelling.

Watch for interactions: combining mefenamic acid with anticoagulants (warfarin), SSRIs or SNRIs increases bleeding risk. It can reduce the effectiveness of some blood pressure medicines and interact with methotrexate and lithium. Avoid taking multiple NSAIDs at once. If you take prescription drugs, check with your prescriber or pharmacist before starting mefenamic acid.

For older adults, the risk of side effects is higher. Doctors usually start at the lowest effective dose and monitor kidney function and blood pressure. Children should only use mefenamic acid if a pediatrician prescribes it and gives exact dosing instructions.

Thinking about buying mefenamic acid online? Choose licensed pharmacies that require a prescription, show clear contact info, and display pharmacist licensing or pharmacy verification seals. Check reviews, confirm packaging and expiry dates on arrival, and keep your receipt. If a site sells prescription drugs without a prescription or offers unrealistic prices, don’t risk it.

If pain is severe, persistent, or accompanied by fever, vomiting, fainting, or other worrying signs, see a doctor right away. For routine cramps, mefenamic acid can work well when used short-term and correctly. Ask your healthcare provider about alternatives if you have chronic pain or any medical conditions that make NSAIDs risky.