Mefenamic acid (often sold as an OTC or prescription NSAID under brand names such as Ponstan, Mephen, Mefen, etc.) has a shelf‑life that’s defined by the manufacturer’s stability studies. While the exact expiration date can vary from one product to another, here are the typical parameters:
| Factor | Typical Information |
|--------|---------------------|
| Expiration range | Most commercially available mefenamic acid preparations have a shelf life of 2–3 years from the date of manufacture, provided they’re stored correctly. |
| Storage conditions | Keep the medication in its original container, tightly closed, at room temperature (usually 15 °C–25 °C / 59 °F–77 °F). Avoid extremes of heat, moisture, and direct sunlight. |
| Where to find the date | Look for an “EXP.” or “Use by” stamp on the outer box, blister pack, or individual tablet container. If the product came in a bottle, the label on the bottle usually shows the date. |
| What to do if you find a date | 1. Check the date – If it’s within the shelf life, the medication should still be stable and safe.
2. Inspect the tablets – Look for any discoloration, unusual texture, or smell. If anything is off, discard the batch.
3. If expired – It’s safest to discard it and obtain a new supply. Using an expired NSAID can reduce efficacy and, in some cases, increase the risk of side‑effects. |
| Stability in common situations | • Room temperature: Most tablets remain stable for the full shelf life.
• Elevated temperature (e.g., 30 °C/86 °F): Shelf life can be shortened, often by a few months.
• High humidity or water exposure: Can accelerate degradation. |
| Manufacturer specifics | Different manufacturers may conduct slightly different stability tests, leading to variations in the stated expiration. Always rely on the date printed by the manufacturer for that specific batch. |
---
Quick checklist for handling expired mefenamic acid
1. Look at the label – If the expiration is past, it’s generally best to dispose of it.
2. Do not use past the date – The drug may have lost potency and could potentially be less safe.
3. Proper disposal – Return unused pills to a local pharmacy or follow your local medication‑take‑back program guidelines instead of flushing them.
---
If you’re unsure
- Contact the manufacturer: They can confirm the recommended shelf life for that specific formulation.
- Consult a pharmacist: They can verify the expiration and advise whether a particular batch is still suitable for use.
---
Bottom line: The expiration date on the package is the best indicator. For most mefenamic acid products, expect a 2–3 year shelf life under proper storage conditions. If you’re in doubt, it’s safest to replace the medication rather than risk reduced efficacy or safety.