Ponac is mefenamic acid, an anti-inflammatory painkiller. It is best known for period pain, where it both relieves the pain and reduces heavy bleeding. It comes as 250 mg capsules, 500 mg Forte tablets, and a suspension for children.
What is Ponac?
Ponac contains mefenamic acid. The South African Medicine Price Registry lists four presentations:
| Product | Schedule | Form | Strength |
|---|---|---|---|
| Ponac | S2 | Suspension | 50 mg per 5 ml |
| Ponac | S3 | Capsule | 250 mg |
| Ponac Forte | S2 / S3 | Tablet | 500 mg |
Mefenamic acid is an NSAID — a non-steroidal anti-inflammatory. Like others in the class it blocks the enzymes that produce prostaglandins, the chemicals responsible for pain, swelling and fever.
What makes it particularly suited to period pain is where those prostaglandins act. Menstrual cramps are caused by prostaglandins driving the uterus to contract, and heavy bleeding is linked to the same chemistry. Mefenamic acid reduces prostaglandin production, so it eases the cramping and typically reduces menstrual blood loss by a meaningful amount. Few painkillers treat both the pain and the bleeding.
The suspension is a paediatric form for pain and fever in children, dosed by weight. Forte simply means the 500 mg strength — not a different medicine.
What is Ponac commonly used for?
- Period pain (dysmenorrhoea) — its most common use, and where it works best.
- Heavy menstrual bleeding (menorrhagia), reducing blood loss as well as pain.
- Headache, including tension headache and some migraine.
- Dental pain and pain after dental procedures.
- Muscular and joint pain, backache, and rheumatoid or osteoarthritis pain.
- Fever, including in children at paediatric doses.
- Pain after minor surgery or injury.
For period pain, timing matters: starting it at the first sign of pain, or the day before a period is due if your cycle is predictable, works considerably better than waiting until cramps are established. Prostaglandins are easier to prevent than to catch up with.
A caution specific to this medicine. Mefenamic acid is used for short courses — a few days at a time. It is not intended for continuous long-term use, and it carries a higher rate of diarrhoea than most NSAIDs, along with a specific concern about overdose (below).
Persistently heavy or painful periods deserve a diagnosis, not indefinite symptom control. Fibroids, endometriosis, polyps, thyroid problems and clotting disorders are all treatable causes, and a painkiller that works well enough is a common reason they go unexamined for years.
How Ponac fits into this medicine category
| Group | Examples | Notes |
|---|---|---|
| Fenamate NSAIDs | Mefenamic acid (Ponac) | Period pain and heavy bleeding; short courses |
| Other NSAIDs | Ibuprofen, diclofenac, naproxen | Similar effect; naproxen also used for period pain |
| Simple analgesics | Paracetamol (Donapan) | Gentler on the stomach; no anti-inflammatory effect |
| Antifibrinolytics | Tranexamic acid | Reduces menstrual bleeding without relieving pain |
| Hormonal treatment | Combined pill, hormonal IUD | Reduce pain and bleeding over the longer term |
| Corticosteroids | Prednisone | Inflammatory conditions, in courses |
For heavy painful periods, mefenamic acid and tranexamic acid are sometimes used together — one for the pain, one for the bleeding. See the pain, inflammation and musculoskeletal medicines hub.
What to check before using Ponac
Speak to a pharmacist or doctor if you:
- Have or have had a stomach ulcer, gastritis or bleeding in the digestive tract.
- Have inflammatory bowel disease — Crohn’s or ulcerative colitis. Mefenamic acid is generally avoided, as it can provoke colitis.
- Have asthma. A proportion of people with asthma react badly to NSAIDs.
- Have kidney or liver disease, heart failure, heart disease or high blood pressure.
- Take blood thinners, aspirin, another anti-inflammatory, steroids, SSRIs, diuretics, ACE inhibitors or lithium — mefenamic acid raises lithium levels.
- Are pregnant. NSAIDs are generally avoided, particularly in the third trimester. Tell your doctor if you are trying to conceive, as NSAIDs can interfere with ovulation.
- Are breastfeeding.
- Are over 65, where stomach and kidney risks rise.
Practical points:
- Take it with or after food, with a full glass of water.
- Start early in a period, and take it regularly through the worst days rather than sporadically.
- Use the lowest effective dose for the shortest time — generally no more than about a week at a stretch without advice.
- Do not combine it with another anti-inflammatory, and check cold and flu remedies for a second NSAID.
- Measure the suspension with the device supplied, and follow paediatric dosing exactly.
Possible cautions and when to ask a pharmacist or doctor
The commonest effects are indigestion, nausea, abdominal pain, headache, dizziness and drowsiness — and diarrhoea, which mefenamic acid causes more often than most NSAIDs.
Diarrhoea on mefenamic acid should not be ignored. It can indicate inflammation of the bowel, and the usual advice is to stop the medicine and seek advice rather than push through it.
Get emergency help for:
- Vomiting blood, or material like coffee grounds.
- Black, tarry stools, or severe stomach pain.
- Bloody diarrhoea.
- Sudden worsening of asthma or wheezing.
- Chest pain, breathlessness, or signs of a stroke — sudden weakness, facial droop, slurred speech or a severe unusual headache.
- Swelling of the face, lips or tongue, difficulty breathing, or a widespread blistering rash.
- Suspected overdose. Mefenamic acid overdose is more likely than other NSAIDs to cause seizures, and needs emergency assessment even if the person seems well. Take the packaging.
Contact your doctor if:
- Period pain is not controlled, or is worsening month by month.
- Bleeding is heavy enough to soak through protection hourly, you pass large clots, or you feel faint, breathless or exhausted — those suggest blood loss worth investigating for anaemia and its cause.
- You have bleeding between periods or after sex, or pelvic pain outside your period.
- You develop swollen ankles, reduced urine output or unexplained tiredness.
- You need it most months for years without anyone having looked for a cause.
Related medicine guides
- Browse Pain, Inflammation & Musculoskeletal Medicines guides
- Read: Prednisone used for
- Read: Donapan used for
Frequently asked questions
What is Ponac used for? Period pain and heavy menstrual bleeding, headache, dental pain, muscular and joint pain, and fever. It contains mefenamic acid.
What is Ponac 250 mg used for? The same conditions — 250 mg is the capsule strength, and Ponac Forte is the 500 mg tablet.
What is Ponac suspension used for? Pain and fever in children, dosed by weight. Follow the instructions exactly and use the measuring device supplied.
Does it reduce period bleeding? Yes. As well as relieving cramps, it typically reduces menstrual blood loss — one of the reasons it is chosen for periods specifically.
When should I start taking it? At the first sign of pain, or the day before your period is due if your cycle is predictable. Starting early works better.
Why does it give me diarrhoea? Mefenamic acid causes diarrhoea more often than other NSAIDs, and it can indicate bowel inflammation. Stop taking it and seek advice.
Can I take it with ibuprofen? No. Both are anti-inflammatories, and combining them raises the risk of stomach bleeding without adding benefit.
How long can I take it for? Short courses — generally no more than about a week at a time without medical advice.