Ibuprofen for Period Pain: OTC vs Prescription and How to Use It
When 400mg is not enough, why 600mg works better, timing rules and how to combine with paracetamol.
Part of the Access Doctor period pain guide.
Key fact: Many women who say ibuprofen “doesn’t work” for period pain have only taken OTC 400mg doses. Prescription ibuprofen 600mg three times daily achieves significantly better COX inhibition and prostaglandin suppression — the difference in effect can be substantial.
Get Prescription Pain Relief Online
Access Doctor GPhC-registered pharmacist independent prescribers can prescribe naproxen 500mg and ibuprofen 600mg for period pain online. No GP appointment needed. Next-working-day delivery.
Start Consultation →How Ibuprofen Relieves Period Pain
Period pain is driven by prostaglandins produced by the uterine lining in response to falling progesterone. Prostaglandins trigger uterine contractions and reduce blood flow to the uterine muscle, causing ischaemic cramping. Ibuprofen is a non-selective COX inhibitor that blocks both COX-1 and COX-2 enzymes, preventing prostaglandin synthesis. Reducing prostaglandin levels directly reduces the intensity of uterine contractions and restores blood flow to the uterine muscle.
OTC 400mg vs Prescription 600mg: Why the Dose Gap Matters
| OTC ibuprofen 400mg | Prescription ibuprofen 600mg | |
|---|---|---|
| Peak plasma concentration | Lower | Higher — ~50% greater than 400mg |
| COX inhibition | Partial | More complete |
| Prostaglandin suppression | Moderate | Greater — directly proportional to dose |
| Daily doses needed | 3 (max 1,200mg/day OTC) | 3 (1,800mg/day prescription) |
| NICE recommendation for dysmenorrhoea | Starting point | Preferred for moderate-to-severe pain |
The OTC daily maximum is 1,200mg (3 x 400mg). The prescription maximum for period pain is typically 1,800mg (3 x 600mg). Do not exceed OTC dose limits without a prescription. If OTC ibuprofen is not controlling your period pain, this is the clinical indication to seek a prescription for 600mg.
Correct Dose and Timing for Period Pain
1
Take the first dose immediately — at the first sign of pain or bleeding
This is the most important step. Ibuprofen must compete with prostaglandins that are already being produced. Taking it at the very start keeps their levels lower throughout day one.
2
Always take with food
Ibuprofen inhibits gastroprotective prostaglandins in the stomach. Taking with food or milk significantly reduces nausea and stomach irritation.
3
Take every 6–8 hours — do not miss doses in the first 24 hours
Ibuprofen’s 2-hour half-life means blood levels fall between doses. Missed doses allow prostaglandin levels to rebound. The first 24 hours are critical.
4
Continue for 2–3 days, then stop
Use for the painful days only. Do not use long-term without medical supervision.
Combining Ibuprofen with Paracetamol
Paracetamol 1g every 4–6 hours is safe and effective to add alongside ibuprofen for period pain. They work by different mechanisms:
- Ibuprofen — peripheral anti-inflammatory, reduces prostaglandin synthesis at the site of pain
- Paracetamol — central analgesia via the brain and spinal cord, modulates pain signal processing
The combination provides better relief than either alone for moderate-to-severe dysmenorrhoea. Maximum paracetamol: 4g (8 standard 500mg tablets) per day. Space doses so you are not taking both at the same time unnecessarily — staggering them provides more even coverage across the day.
Side Effects and Precautions
- GI symptoms — nausea, heartburn, stomach pain; most common side effect; minimised by taking with food
- Headache, dizziness — mild; usually transient
- Fluid retention — with regular use; mild ankle swelling possible
Seek urgent advice if you experience black or tarry stools, vomiting blood, or severe abdominal pain while taking ibuprofen.
Ibuprofen is contraindicated in: peptic ulcer disease or GI bleeding history, significant kidney impairment (eGFR <30), aspirin-sensitive asthma, third trimester pregnancy, and severe heart failure. Discuss with a prescriber if you take warfarin or other anticoagulants.
Ibuprofen vs Naproxen for Period Pain
Both are effective first-line NSAIDs for dysmenorrhoea. The main practical difference is dosing frequency: ibuprofen 600mg requires three daily doses; naproxen 500mg requires only two. For women who find it easy to remember three doses, ibuprofen’s slightly faster onset can be an advantage on day one. For sustained all-day relief with fewer doses, naproxen 500mg twice daily is often preferred. See the full comparison: Naproxen for Period Pain.
Get Prescription Ibuprofen 600mg Online
Access Doctor GPhC-registered pharmacist independent prescribers can prescribe naproxen 500mg and ibuprofen 600mg for period pain online. No GP appointment needed. Next-working-day delivery.
Order Ibuprofen 600mg →Frequently Asked Questions
What dose of ibuprofen should I take for period pain?
OTC starting dose: 400mg every 6–8 hours with food (max 1,200mg/day). For moderate-to-severe period pain, prescription 600mg three times daily is significantly more effective.
Is prescription ibuprofen 600mg better than OTC 400mg?
Yes, for moderate-to-severe pain. The higher dose achieves greater COX inhibition and prostaglandin suppression. Many women who report ibuprofen ‘doesn’t work’ have only tried 400mg.
When should I take ibuprofen for period pain?
At the very first sign of pain or bleeding. Taking before prostaglandin levels peak is the single most important thing you can do to maximise effectiveness.
Can I take ibuprofen and paracetamol together?
Yes — safe and more effective than either alone. They work by different mechanisms. Paracetamol 1g every 4–6h alongside ibuprofen provides better overall relief.
Should I take ibuprofen with food?
Yes. Always take with food, milk, or a full glass of water to significantly reduce GI side effects.
References
- National Institute for Health and Care Excellence (NICE). Heavy menstrual bleeding: assessment and management (NG88). 2018 (updated 2023). nice.org.uk/guidance/ng88
- Marjoribanks J et al. Nonsteroidal anti-inflammatory drugs for dysmenorrhoea. Cochrane Database Syst Rev. 2015. PubMed: 26224322
- NHS. Ibuprofen. nhs.uk/medicines/ibuprofen-for-adults
Medical disclaimer: This article is for informational purposes only. Period pain can be a symptom of an underlying condition requiring assessment. In an emergency call 999.