Mefenamic Acid

Period Pain

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  • Mefenamic Acid

Mefenamic Acid

Period Pain
  • Medication features

    Mefenamic acid is an example of an NSAID, which is a non-steroidal anti-inflammatory drug. It is an effective medication for a woman who suffers from extreme pain due to their period. It is taken three times a day for lasting relief.

    • Used to treat period pain
    • Can reduce bleeding
    • Faster acting than conventional painkillers


NOTE: After selecting this product, you will need to complete a short assessment, so we can make sure this medication is suitable for you. Pricing is provided as a reference only. The final decision on issuing this medication remains with our Prescriber / Pharmacist.

Mefenamic acid belongs to the same group of drugs as ibuprofen – non-steroidal anti-inflammatory drugs. They are better at reducing pain than over the counter medications and have proven to be effective in managing symptoms of period pain.


  • What is mefenamic acid?

    Mefenamic acid is a nonsteroidal anti-inflammatory drug (NSAID), which is the name for medicines that are used to treat mild-to-moderate pain and inflammation. Mefenamic acid tablets are usually taken to provide relief from period pain (dysmenorrhoea), reduce the symptoms of heavy periods (menorrhagia), and treat migraines caused by periods.

  • How does mefenamic acid help to relieve period pain?

    Mefenamic acid relieves period pain by blocking the production of prostaglandins, which are hormones released by your womb before and during your period. Prostaglandins cause your womb to contract, and if too many are released then these contractions can become painful. Mefenamic acid causes fewer prostaglandins to be released.

  • How does mefenamic acid help to stop heavy periods?

    Heavy periods, like period pain, can happen when your womb releases too much of the hormone prostaglandin. Mefenamic acid blocks the production of this hormone, causing your periods to become lighter. Mefenamic acid has been shown to reduce heavy bleeding by between 20 to 50%.

  • How long does it take for mefenamic acid to relieve period pain?

    Mefenamic acid takes between 2 - 4 hours to kick in and start easing your period pain. Each 500mg dose of mefenamic acid kills pain for up to 8 hours, so you may need to take it two or three times a day for all-day relief.

Side Effects

There is always a risk of side effects with all medications. Some of these can be quite mild and can subside over time. Others are more serious and should be reported to your GP right away if you experience any side effects. Please contact a member of our team if you are concerned about any potential side effects that may occur when taking mefenamic acid.

Some common side effects reported with mefenamic acid use include:

  • Swelling of the hands and feet
  • Skin reactions
  • Diarrhoea
  • Nausea
  • Vomiting
  • Fatigue
  • Headache
  • Photosensitivity


Info Leaflet

Before taking any medicines, regardless of whether they are over the counter or prescription-only, it is essential always to read the patient information leaflet.

Patient Information Leaflet