Mefenamic acid 500mg tablets: Has anyone... - Endometriosis UK

Endometriosis UK
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Mefenamic acid 500mg tablets


Has anyone been given this for their endometriosis? Just been prescribed it after trying loads of painkillers and wondered if it helped or even worked for them x

13 Replies

It's the only thing that ever worked for me. Recently I've not been able to get hold of it from my local pharmacy and was given Naproxen instead, which I would avoid like the plague as it's made me feel incredibly sick!

Mefenamic acid gives me a few hours of relief and without it I would probably have gone mad by now. However, it upset my stomach horribly at 500mg doses, so I was given 250mg tablets instead and I just built up the dose as needed. Sadly, there is only so much I can take before it stops working again or unwanted side-effects start, which I think is true of most anti-inflammatory drugs.

I had mefenamic acid and it was a god send, but since moving I've been given Naproxen, although I do prefer mefenamic acid as it targets the abdominal area begetter than other anti inflammatory.

I've never been sick on either, although a larger dose of Naproxen leaves me feeling very tired.


I was given these! They make my tummy feel like a washing machine the first I took them and they gave me diarhoea, however I did try again felt ok but didn't really do much for the pain if I'm honest. Everyone is different though

Good luck with them


I use it for its anti inflammatory qualities but I use other painkillers too to relieve the pain, and although some people prefer Naproxen I found that mefenamic acid was gentler on the stomach. Naproxen gave me horrendous acid reflux. However, saying that my pharmacist says it is actually a stronger drug than Naproxen and you must take omeprazole with it. This drug will prevent the mefenanic acid from attacking your stomach lining, a major side effect of all anti inflammatories (including ibroprofen). Of course having food with it as well will help prevent this. I don't think doctors always prescribe omeprazole - maybe to save money? - but if you are using it for a long period I think you should ask for some. You don't want stomach ulcers to deal with further down the line too...

I agree with the replies above who found mefenamic a HUGE help. It not only gave relief from agonising period & endo pain, until my early menopause. but I also treasure it because mefenamic stops my chronic migraines in their tracks. I have even used it to treat my UTIs, which are always the galloping & volcanic excruciatingly painful type.

I've always taken 500mg, and with food of some sort going into my stomach....even several biscuits & a cuppa (e.g. Often my need for mefenamic strikes in the night). And I do agree: if poss, probably safest to take it with a PPI. You certainly shouldn't take mefenamic with another NSAID...when I was younger, my gp negligently continued to allow me mefenamic on repeat prescription, at the same time he began to repeat prescribe a daily NSAID for my chronic spine pain....and failed to spot his mistake. I was too ignorant to spot it myself....but eventually a hospital pharmacist did spot the big mistake & sorted me out. Needless to say, my gp was very embarrassed. I'm sure those years of occasionally doubling up on NSAIDs have made my chronic upper & lower GI probs even worse than they might've been otherwise...during those years my gp didn't have me on a PPI...he never even suggested this

I am 60 and have systemic lupus (infant onset) and the mefenamic leaflet says it's contraindicated for SLE patients, but my drs & consultants let me use it as needed...which in recent years has only been, say 6-10 tabs per year

I am taking these and work for me I have to take omeprazole tablets with them as the acid from the tablets gave me terrible stomach cramps

I used them in conjunction with tranexamic acid and together they worked wonders. I also fell pregnant after years of trying which I don't think was a coincidence! Sorted me right out in more ways than one x

I was prescribed it by my GP. It doesn't seem to do much for my pain. Of course, different drugs have different effects for people, I'm sure it's a godsend for some.

I find it great but can only take it at night as makes me very drowsy

I found these did not help my pains and made me sick, so stopped taking them.

Thanks for all the advice only just started taking it so hopefully it will work. I also had naproxen which made me feel so sick and horrible stomach cramps. Fingers crossed this will do the trick x

Hiya, please read this clip from the website. Mefernamic acid is a Nsaid and has to be used correctly to work. They are a pain blocker and NOT a pain killer. I hope this is some help to you. They didnt help me.

Theoretically, NSAIDs would seem to be a good choice for relieving menstrual pain because most of them work by blocking the production of all prostaglandins. The result is less pain, swelling, and inflammation. However, since NSAIDs work by stopping the production of the pain-causing prostaglandins, they must be taken before any of these chemicals are produced. In other words, you must start taking NSAIDs at least 24 hours before you expect to experience pain. If you delay taking them until after you feel pain, the medication cannot block the pain-producing chemicals that have already been released, so they will not alleviate pain.

If you are using NSAIDs for ovulation pain or menstrual pain, it is recommended that you start taking them as directed at least 24 hours before you expect to ovulate or 24 hours before you expect to start bleeding. If you have an unpredictable menstrual cycle, you may want to take them for a week or more before you expect menstruation to begin. To be effective, it is important to take NSAIDs regularly every six hours so that no pain-producing chemicals are produced during ovulation or menstruation. Another advantage of taking certain NSAIDs is that they decrease the amount of menstrual bleeding (1, 2).

Yes me been in awful pain and the doctor said these would help seem to be taken the edge off things x how are you now?

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