Mirena vs “Usual” Medical Treatment for Heavy Menstrual Bleeding – Depends on What “Usual” Is

MirenaThey’ll be a lot of press this week over a study conducted in the UK reporting that the levonorgestrel IUD (Mirena) is superior to usual medical treatment  for the treatment of heavy menstrual bleeding (menorrhagia).

“Usual” medical treatment for 75% of the women in the UK study was tranexamic or mefamanic acid – drugs that control bleeding through the coagulation pathway, and which are not widely used in the States.

Here in the US, we tend to use  oral contraceptives and progestins to treat menorrhagia. Unfortunately, the UK investigators  did not break out the comparison between these hormonal treatments and the IUD,  so we really don’t know how well Mirena would perform compared to usual treatment here.  However, given years of seeing how effective birth control pills are in decreasing menstrual flow, I’m going to assume that they still work as well as they always have, and not necessarily better or worse than the hormonal IUD.  Each method has its pros and cons, and every woman is different.

The investigators also reported that the Mirena IUD was less effective than usual treatment in women whose BMI is under 25. This is not surprising, since heavier women could have an element of estrogen excess that would be better addressed by hormonal therapy such as Mirena or birth control pills rather than anti-fibrinolyics such as Tranexamic acid.

None of this, by the way,  is meant to discourage women and their doctors from using Mirena to treat heavy periods – it is indeed a very effective treatment and one that I offer my own patients.

Just trying to give the anticipated hype some context and perspective.

8 Responses to Mirena vs “Usual” Medical Treatment for Heavy Menstrual Bleeding – Depends on What “Usual” Is

  1. Well, and what’s “heavy,” and at what point does it in fact need “treatment”? And has anyone ever looked into how diet and exercise affect heavy bleeding? Completely anecdotal, but I’ve had heavier periods at times in my life when I’ve weighed more.

    I’d love to know your thoughts on these issues!

    • Heide – the study used a scale score to define efficacy, and did not say what the entrance criteria was for the study. Diet and exercise? Depends on the woman and her weight. Weight has a complex interaction with ovarian function, especially in women with insulin resistance or PCOS, and the opposite in women with exercise induced amenorrhea or anorexia, so the answer to your question on weight is not a simple one. But all good food for thought.

      Thanks for reading, and for your comment.


  2. I think Mirena is lovely for those of us who are over 40, don’t have realistic fertility to care about, and want to set the welcome mat out for menopause without the risks of the pill. I realize there is always Micronor, but this is like having a Micronor pump. I’m surprised there hasn’t been a stronger marketing to this my group. Perhaps in time.

    • Celeste –
      Mirena is a great option. I just tend to cringe when folks start using terms like “better” or “Best” when there are multiple treatment options that are similarly effective, when superiority is defined by an arbitrary scale, and when there are multiple considerations that might affect the decision as to which treatment to use. Medicine is not a horse race.

      Glad you’ve found your personal winner.

      Thanks for reading.


  3. the BMI paragraph doesn’t make logical sense. Is it meant to read the mirena is less effective with bmi over rather than under 25?
    As written it suggests the mirena would be a good choice for the US as 66% of women are heavy rather than light

    • s friel –
      You are absolutely right! That paragraph originated as a longer one on weight and menorrhagia and the fact that heavier women could have an element of estrogen excess making hormonal treatment more effective than the antifibrinolytic drugs, perhaps limiting the applicability of this latter class of drugs in the US for menorrhagia. When I shortened it (one of my new year’s resolutions was to write shorter blog posts), I missed my own point!

      This is what comes of publishing without an editor…

      Thanks for picking up my error. I corrected myself up there and it now reads as originally intended.


  4. So sorry – I’m confused with the comment “…less effective with a BMI under 25” Is it, in fact, less effect in women with a BMI under 25? I have a BMI of about 22 and ridiculous menorrhagia – Mirena has been suggested to me. I am a bit complicated in that I also have a Congenital Myasthenic Syndrome which becomes worse every month just before and during my period. Just doing as much research as I can – I know we are all different – but if it is truly less effective in smaller women, why should I bother to try… seems like it will be a good 6 – 9 months before I notice a difference (if any)…

  5. I am 43 and have been suffering from heavy periods for several years now. Heavy means soaking a super + tampon in under an half hour! Also passing big clots. I also have nasty cramps and feel like crap during my period to the point I have to miss work (I am a teacher and on my feet a lot).
    I saw my gyno this morning after an ultrasound that said I had fibroids in my uterus. She suggested Mirena and Tranexamic acid. Is that extreme? But I am game for anything that will make my periods less bothersome.

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