You know that medication you spent $50 on to prevent pregnancy? If you weight 11 lbs more than average, it’s completely useless.

Mother Jones reports that an emergency contraception pill in Europe–which is basically the same thing as the only sort of emergency contraception available without a prescription in some places, like the US, is completely ineffective if you weigh more than 80 kg, aka 176 lbs. And it’s less effective for women weighing upward of 165 pounds, so much so that the European labels are gonna suggest you not take it at all.

I’m gonna repeat that.

In certain places (e.g., the United States), Plan B is not really that effective for the average woman, and if you weigh 11 pounds more than average,  You Are Completely Incapable of getting a working form of emergency contraception without a prescription.  (Oh I’m sorry, did you want this $50 medication to also work? Because I thought maybe you just wanted the nice-looking box.)

I’m gonna repeat that yet again, quoting MJ:

“The European manufacturer of an emergency contraceptive pill identical to Plan B, also known as the morning-after pill, will warn women that the drug is completely ineffective for women who weigh more than 176 pounds and begins to lose effectiveness in women who weigh more than 165 pounds.”


Now let’s put on our anti-oppressive hierarchy hat, and translate that into societal implications:

A medication that is $50 a pop and is many people’s only reasonably accessible form of emergency contraception, is Completely. Useless. for those of us who are a staggering eleven pounds heavier than average. (I know, it took a lot of burritos, shunning of any physical activity whatsoever, and willful ignorance to get to this point. And then it took even more burritos to make up for all the calories I was burning via unprotected sex. )

Oh hey, and who normally gets the trope stuck to them that they’re stupid and make bad life decisions, like failing to prevent a pregnancy they don’t want and certainly can’t afford?: poor fat women. And guess who can’t use Plan B and probably also can’t afford the alternatives: Poor fat women. So who’s been looking like they’re confirming their own inherent laziness and stupidity when really they weren’t told that a medication marketed to everyone doesn’t work for them: poor fat women.  Thank God at least poor women aren’t more likely to be fat than women of higher socio-economic status. Then we would have a really doozy of a combo on our hands.

Bonus Round Pop Quiz:  How many top athletes also can’t use  one of the most popular forms of emergency contraception without reduced effectiveness?

“Huh?” You say after all that. Don’t worry. I got you covered.


Plan B is useless to you if you weigh more than 176 pounds.

If all this is really true, I’m allowed to set something on fire, right?


6 thoughts on “You know that medication you spent $50 on to prevent pregnancy? If you weight 11 lbs more than average, it’s completely useless.

  1. This kind of problem with drug effectiveness and dosage is almost universal, in one way or another, because clinical trial data is almost universally flawed, for a number of reasons but including the fact that, even on clinical trials, medications are taken very poorly, for a large number of complex reasons So, in general, there is very poor understanding of dosage levels and effectiveness of drugs. There is one pharmaceutical company that I know of looking into this massive problem, and I know that the faculty of pharmaceutical medicine in London and the UK’s dept. of health is very concerned with how to tackle the problem, but there needs to be systematic serious attention to the paucity of our information about pharmaceuticals.

  2. @Paula Boddington – Thanks for filling in some of the contextual info.

    @ptittle – Thanks! I don’t have my own blog, but I can list some of the bloggers who have influenced me over years, and whose styles I have probably imitated to various degrees: (also worth listening to his now-many podcasts) (also an archive of an old blog)
    And I see you already have IBTP on your own blogroll.

  3. Interesting. As with nearly everything written about drugs, I wish there were more discussion of mechanisms (or at least possible mechanisms.) It would be odd if weight alone did this- if a tall but thin person had the same reaction as a short but plumper one- as lots of drug interaction relates to fat absorption and related things- but who knows. It’s very hard to say w/o at least some discussion of mechanisms, and there’s none at all there, or in any of the linked articles, it’s sad to say. (Though it does seem that the woman who actually did the research says she’d still recommend it to heavier women. Why, exactly, wasn’t discussed, sad to say.)

  4. This is quite startling. I worked in a birth control clinic for 8 years and we gave out Plan B (for $12, or free if the woman couldn’t afford it, thankfully) all the time and I never heard about its effectiveness being limited by weight. However, in retrospect this makes sense because certain hormonal contraception methods – including low-dose estrogen pills, which are very popular, and the Evra patch – are not effective in women above a certain weight. The weight we were told was 198 lbs., but in reality it could well be less.

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