Painful and heavy periods: could Mefenamic Acid be the answer?

by Mary Hargreaves · Oct 29, 2021

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Reviewed by Dr. Melanie Davis-Hall on Oct 29, 2021

Packet of mefenamic acid on a pink background
If you suffer with intense, soul-destroying period pain or heavy periods and ibuprofen just doesn't cut it; mefenamic acid might be the answer. Here's the lowdown on the benefits and side effects of this anti-inflammatory drug before you try it.

What’s the lowdown?

  • Period pain is caused by contractions in the womb which cut off blood supply and cause the body to release pain-triggering chemicals
  • While these chemicals are being released, your body also produces the hormone prostaglandin, which cause further pain
  • Mefenamic acid is a nonsteroidal anti-inflammatory drug (NSAID), like ibuprofen, that is commonly used to treat painful or heavy periods
  • NSAIDs including Mefenamic acid work by blocking the enzyme in the body that produces prostaglandin
  • Mefenamic acid is one option for those who suffer with intense period pain, but is not known to be more effective than ibuprofen
  • NSAIDs have potential side effects, which are more likely to occur the longer you take them
  • Hormonal contraception could be a better choice for women looking for a long-term solution


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Jump to What is period pain? | What is mefenamic acid? | What other treatments are there for period pain? | When is it time to see a doctor?

If you’ve ever tried explaining period pain to a cis man, you know how difficult it can be to describe. It’s something most of us are familiar with, and it can vary from person to person as well as from period to period. 

For some, though, period pain isn’t a mild monthly annoyance. While the majority of us can fill a hot water bottle and pop a couple of paracetamol, some people experience periods that are so painful, they impact their ability to live their normal lives.

There are several treatments that doctors may suggest for especially painful periods, but one which isn’t so well known is mefenamic acid. If ibuprofen isn’t working for your cramps, this might be one to try.

We’ll be getting into this in more detail in a moment, but first, let’s explore exactly what period pain is and why most of us experience it.

What is period pain?

There’s a reason we refer to period pains as ‘cramps’ – that’s exactly what they feel like. At the beginning of our cycle, when menstruation occurs, our bodies experience a drop in hormones, caused by an egg remaining unfertilised, and respond by shedding the lining of the womb. 

Your womb contracts all the time, but these contractions are usually so mild that you don’t feel them. During your period, however, your womb contracts much more intensely in an effort to push the lining it is shedding out of your body. These contractions push down on the blood vessels within your uterus, momentarily cutting off the blood supply. As a result, the tissues in your womb experience a lack of oxygen, and consequently send out pain-triggering chemicals. Hello, cramps.

What are prostaglandins?

If all of that wasn’t enough to take in, there are other players to introduce to the table: prostaglandins. When your body releases the chemicals that trigger pain, it also releases prostaglandins, which are lipids that encourage further contractions and – you guessed it – more pain. Everything’s just one big, lovely cycle, isn’t it?

Why do some people experience severe period pain?

When someone experiences frequent and intense cramps during their period, this is known as dysmenorrhea. Dysmenorrhea is an umbrella term that refers simply to the higher level and frequency of pain that one experiences, and can be present on its own (primary dysmenorrhea) or can result from an underlying condition.

Dysmenorrhea can occur as a result of medical conditions such as endometriosis, fibroids, pelvic inflammatory disease or adenomyosis. You can read more about this on the NHS website. As we said earlier, however, some people who menstruate experience dysmenorrhea without an underlying condition.

There is evidence that primary dysmenorrhea could be due to increased production and release of prostaglandins. Prostaglandins cause pain at the same time as causing inflammation, a vital part of the healing process that happens all over our bodies. In many women with primary dysmenorrhea, the level of pain they feel during their periods decreases as they get older.

There is lots of useful information about dysmenorrhea on the American College of Obstetricians and Gynaecologists’ website.


What is Mefenamic Acid?

Like ibuprofen, mefenamic acid is a nonsteroidal anti-inflammatory drug (NSAID). NSAIDs work by blocking an enzyme that the body uses to make prostaglandins. As prostaglandins cause inflammation and trigger pain, preventing them from being created can result in reduced discomfort.

Mefenamic acid has been shown to be similarly effective to ibuprofen in the treatment of other painful conditions, but of all the NSAIDs, research still touts ibuprofen as the best option for pain relief with dysmenorrhea. NSAIDs come with side effects, and they’re pretty important to consider.

What are the side effects of Mefenamic Acid?

NSAIDs in general come with a list of potential side effects. The side effects associated with NSAIDs are known to be more severe if you take a high dosage for a longer period of time. The NHS lists possible side effects of NSAIDs as:

  • Indigestion
  • Stomach ulcers
  • Headaches
  • Drowsiness
  • Dizziness
  • Allergic reactions

You should not take NSAIDs if you suffer from asthma or kidney problems.

Mefenamic acid vs ibuprofen for period pain

Studies have found the effectiveness and side effects of mefenamic acid and ibuprofen to be similar, and one systematic review found no statistical difference between different NSAIDs for these factors. There doesn’t appear to be much evidence that shows that either mefenamic acid or ibuprofen are superior to one another.

As an alternative paracetamol is safer than ibuprofen in terms of its side effects and may be worth trying first, but it has shown to be less effective at reducing period pain.

Can you take mefenamic acid with Ibuprofen?

No as they have similar side effects, these medications should not be taken together.

Mefenamic acid vs naproxen for period pain

Studies have shown that naproxen is slightly more effective than mefenamic acid at reducing pain. It was found to reduce work and school absences due to period pain. They have similar side effects and both are prescription only medications.


What other treatments are there for dysmenorrhea and period pain?

Some find that the intensity of their period pains is reduced with hormonal contraception. Hormonal contraception thins the lining of the uterus, meaning the body needs to produce fewer prostaglandins to cause contractions and shed the lining. Less prostaglandins mean less pain. Hormonal contraception can also alter the intensity of your bleeding, not just the pain associated with it.

A systematic review of eighteen research studies found that hormonal contraception was the best option, and that NSAIDs should be a first option only for those who did not wish to take hormonal contraception.

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Some people will find that their hormonal contraception causes irregular bleeding or spotting within the first few months. This should level out over time. The hormonal IUS (coil) might be the best option for those wanting to reduce their bleeding significantly. A review looking at data from over 2000 women found that the hormonal IUS was more effective than oral contraceptives (the pill) at reducing heavy menstrual bleeding.

We recommend checking our reviews to see which contraceptives other women found helpful in reducing period pain, or use our contraception recommender to find the best contraception for you. We also have a blog all about contraception for painful periods, which you might want to take a look at.

Contraception recommender | The Lowdown

Can starflower oil help with period pain?

Starflower oil is a supplement derived from the borage plant, it contains a high concentration of gamma-linolenic acid (GLA), an omega-6 fatty acid that can reduce inflammation. This means it’s helpful in easing hormonal symptoms associated with PMS, as well as sore boobs and hot flushes. For more information on the benefits of starflower oil, check out our product page to buy directly from us or purchase from Amazon (our affiliate link, checked by doctors!)

There are some medication interactions, so have a chat with your GP before starting to take starflower oil if you’re using prescription medications to help with period pain.

When is it time to see a doctor?

If you have severe period pain and over-the-counter medications aren’t working, or if you’re noticing other symptoms, it might be time to book an appointment with your GP. 

A variety of symptoms, such as painful sex, bleeding between periods and very heavy periods, could be a sign of an underlying condition. If this is the case, you might have secondary dysmenorrhea (dysmenorrhea caused by another condition) and your doctor will be able to investigate this.

If you are experiencing painful periods and want to discuss contraceptives that might help, you can also speak to one of our lovely doctors. They’ll be able to go through your options with you and can offer advice for next steps. You can also order the pill through us, if hormonal contraception is a route you’d like to go down for tackling your painful periods. We have twenty different options to choose from.

If you suffer from period pain, you are not alone – one review estimates that 45-97% of women in the UK could have dysmenorrhea. Speak to your doctor and explore your options; what may or may not work for you might take time to figure out, but you don’t have to suffer in silence.

Talk to one of our friendly doctors

  1. Dysmenorrhea: Painful Periods. (2020). ACOG.

  2. Leslie, R. D. G. (1977). Mefenamic Acid Compared with Ibuprofen in the Treatment of Rheumatoid Arthritis. Journal of International Medical Research, 5(3), 161–163.

  3. Lethaby, A., Hussain, M., Rishworth, J. R., & Rees, M. C. (2015). Progesterone or progestogen-releasing intrauterine systems for heavy menstrual bleeding. Cochrane Database of Systematic Reviews. Published.

  4. Mital, P., Garg, S., Khuteta, R., Khuteta, S., & Mital, P. (1992). Mefenamic Acid in Prevention of Premature Labour. Journal of the Royal Society of Health, 112(5), 214–216.

  5. NHS website. (2021a, May 26). Period pain. Nhs.Uk.

  6. NHS website. (2021b, October 7). NSAIDs. Nhs.Uk.

  7. Roy S. A double-blind comparison of a propionic acid derivative (ibuprofen) and a fenamate (mefenamic acid) in the treatment of dysmenorrhea. Obstetrics and Gynecology. 1983 May;61(5):628-632. PMID: 6835617.

  8. Ylikorkala, O., & Dawood, M. Y. (1978). New concepts in dysmenorrhea. American Journal of Obstetrics and Gynecology, 130(7), 833–847.

  9. Zahradnik, H. P., Hanjalic-Beck, A., & Groth, K. (2010). Nonsteroidal anti-inflammatory drugs and hormonal contraceptives for pain relief from dysmenorrhea: a review. Contraception, 81(3), 185–196.

  10. Zhang, W. Y., & Li Wan Po, A. (1998). Efficacy of minor analgesics in primary dysmenorrhoea: a systematic review. BJOG: An International Journal of Obstetrics and Gynaecology, 105(7), 780–789.

  11. Zondervan, K. T., Yudkin, P. L., Vessey, M. P., Dawes, M. G., Barlow, D. H., & Kennedy, S. H. (1998). The prevalence of chronic pelvic pain in women in the United Kingdom: a systematic review. BJOG: An International Journal of Obstetrics and Gynaecology, 105(1), 93–99.

Mary Hargreaves is a writer and author with a passion for women’s reproductive health. She has a Masters in Clinical and Health Psychology, and has worked in scientific research across a range of disciplines.

Dr Becky is part of The Lowdown’s medical team. She works as a GP in Sheffield where she fits and removes coils and implants, and has previously worked in fertility services and sexual health clinics. Becky also works as a researcher looking at improving access to sexual and reproductive healthcare.