Friday Weird Science: Fibransin and the “problem” of female sex drive

Sci was toddling around the internet recently (as is her wont), when she came across the work of Dr. Petra. If you’re in to learning about sex, sex education, and everything else from a scientific point of view, Sci highly recommends Dr. Petra. This is a blogger who tells it like it is.
(Sci also just found out that Seed has a current article on humans as some very sexy beasts. Sci is suitably amused, and you should be too).
And it was an article from the awesome Dr. Petra which notified Sci of the current stuff going on with this drug called flibanserin, which has to be one of the WORST drug names. Sci keeps wanting to call it fibansin, or fibanserin, or flibansin. FLIBANSERIN?! Two syllables too many.
As you may know by now, the FDA rejected flibanserin for use in treatment of Hypoactive Sexual Desire Disorder (HSDD). Sci thinks this was extremely justified, as the results of the studies on flibanserin, first off, haven’t been PUBLISHED. This means they haven’t been peer reviewed. And there might be some good reasons. Neuroskeptic gave some great coverage of this. So far it looks like:

1) The trials did not show a statistically significant difference for the co-primary endpoint, the eDiary sexual desire score.
2) The Applicant’s request to use the FSFI [a questionnaire] desire items as the alternative instrument to evaluate the co-primary endpoint of sexual desire is not statistically justified and, in fact, was not supported by exploratory data from Study 511.77, which also failed to demonstrate a statistically significant treatment benefit on desire using the FSFI desire items.
3) The responder rates on the important efficacy endpoints for the flibanserin-treated subjects, intended to demonstrate the clinical meaningfulness, are only 3-15% greater than those in the placebo arm.
4) There were many significant medical and medication exclusion criteria for the efficacy trials, so it is not clear whether the safety and efficacy data from these trials are generalizable to the target population for the drug.

Um. Owie. So the whole thing was by questionnaire, which isn’t necessarily bad, except the questionnaire wasn’t itself proven to be any good. So then the results may not be any good. And the results they GOT suggest that even if the results WERE in fact an accurate representation, flibanserin doesn’t work any better than placebo. And even if it DID, there were so many exclusion criteria that we have no idea if the women used in the questionnaire even represented the regular target population. Excellent smackdown, FDA.
But there’s another deal here that Sci wishes to address, and that would be the issue of HSDD. Hold on to your hats.


As Neuroskeptic again so accurately points out, the disorder of HSDD is…remarkably undefined. I don’t necessarily agree with Neuroskeptic on things like Generalized Anxiety Disorder (GAD), but I think they have HSDD pretty well down. Here’s the thing. With issues like GAD, we have some ideas of what problems might be occurring in the brain to make the symptoms occur. We have drugs that can sometimes help with it. And while it may just be a case of being “generally anxious”, it also prevents a patient from functioning normally. When it prevents a patient from doing normal activities like their grocery shopping and going to work, and prevents successful social interaction and makes the person miserable, we’ve got a problem.
But what IS HSDD exactly? Simple, you might say, it’s the same as male erectile dysfunction! Nope. Not at all. Most masculine erectile dysfunction (ED) has a physical basis. Erections work by having blood flow go into the penis via vasodilation and stay there in the corpus canvernosa, causing rigidity. This is maintained by vasoconstriction of the vessels going OUT, so the blood stays in. Many cases of ED are caused when you can no longer vasoconstrict your outgoing veins from the penis effectively, and blood therefore doesn’t stay in the penis and flows out. Viagra, that champion of ED, works by increasing the vasodilation of the blood vessels going IN, allowing more blood to get in and the erection to be easier to maintain. For more on this, Sci has a post or two on it.
SO that’s male ED. But female HSDD? Well, blood flow to the clitoris doesn’t appear to be a problem. It’s not a problem of not getting the job done. It’s a problem of not having enough sexual desire.
But to this, Sci has a question: How much sexual desire is “enough”? Do women really need a sex pill?
And before you all say “well I have low libido and yes I do”, well…do you? Who exactly determines what is normal? What IS normal libido for a woman? Well, Cosmo will tell you that if you don’t want it at LEAST 7 times a week and tying up your hair with an extra thong for your many sexy times, you’re clearly a horrible person who is entirely failing your partner or you have deep psychological issues. But Sci wanted some real information and so she turned to Pubmed.
And she found a lot of stuff on “sexual arousability” and stuff on the “sexual health of couples” and changes in “arousability” throughout the menstrual cycle. But that’s not the same as DESIRE. Your ability to get it on and have a good time isn’t necessarily consistent with how horny you are at the time. And the studies on “sexual activity” don’t tell you anything about whether the women had high or low sexual DESIRE. The closest I got was this, which talks about sex in older couples, but asking a women whether she’s having ENOUGH sex isn’t the same as asking her how often she DESIRES to have sex.
So what is normal? WELL DANGIT I DON”T KNOW. And you don’t know. And Cosmo doesn’t know. And it looks like Pubmed doesn’t know either.
So I say, before you go about diagnosing women with HSDD and telling them they have a problem (which could arise from many sources), can we first answer the question of what exactly is a normal sex drive in a woman? The answer might surprise us all. Because here’s the thing. Until we know for real what an average woman’s sexual desire looks like (how many times per week does she desire sex, how many times per week does she THINK she should desire sex, and how this is affected by things like age and self-perception), if you diagnose yourself with HSDD…you’re never wrong. Because we don’t know what’s right.
So before we say we need a pill, let’s find out what the condition is.

14 Responses

  1. True, true! Does vaginismus figure into this as well? After much discussion with a lady that has that condition, I think it’s less “psychosomatic” than the doctors say. I think it’s psychophysiological, if that’s a word. At some point in puberty, some girls start instinctively experimenting with penetration. Some never get that instinct, and that’s all I think vaginismus is – How would anyone’s body react when an undesired penetration is happening? For women with said condition, I think they are being perfectly natural – for themselves, on one end of a sexual spectrum.
    Maybe for some ladies it’s even moreso, and they just don’t feel any need for any sex at all ever. Would that be so wrong? Maybe increases risk of some health problems, but eliminates just as many risks at the same time.
    It’s kind of like being gay: Most likely will eliminate you from the gene pool, but who cares? It’s natural human sexual diversity, and who needs that many more people anyway?

  2. I think the disorder is defined as “does not find nerdy male research scientists attractive, and finds they smell faintly of cat piss.”

  3. I think the disorder is defined as “does not find nerdy male research scientists attractive, and finds they smell faintly of cat piss.”

  4. I wonder how much HSDD is a case of “don’t desire you“.
    In all seriousness, HSDD sounds like it could just as easily be the presentation of a whole host of conditions (including the known side effect of various drugs, e.g. SSRIs), rather than a well defined condition.
    @1, Vaginismus, on the other hand, sounds perfectly well defined, no matter what its cause is.

  5. Can’t we apply the same standard to HSDD that we apply to other psychopathologies? If it’s interfering with your life, it’s worth treating.
    I guess I feel like if you want to want to (not a typo!) have sex three times a day, and there’s a pill that can do that for you (not this one, apparently), why not take it?

  6. Can’t we apply the same standard to HSDD that we apply to other psychopathologies? If it’s interfering with your life, it’s worth treating.
    I guess I feel like if you want to want to (not a typo!) have sex three times a day, and there’s a pill that can do that for you (not this one, apparently), why not take it?

  7. [Quick note, @ CS Shelton — “psychosomatic” and “psychophysiological” are essentially synonymous. Psychosomatic illnesses and illnesses with psychosomatic features are physiological afflictions that are caused or exacerbated by psychological distress.]
    I mean, if HSDD were a more well-defined disorder, and if there were actual symptoms actually rooted in a woman’s physiology, I’m all for putting in the research to find a medication to relieve them. But I think Neurotopia and Neuroskeptic have very articulately demonstrated that HSDD is so poorly defined that it’s out of the question to research the underlying physiological phenomena, much less a medication to treat them. And to play around with proper research methodology–shameless! Diagnostic criteria, medical research, scientific rigor: Filbanserin does without them all. Boo Filbanserin!

  8. I think that all else aside there’d be a demand for a pharmaceutical that increased sex drive, and the creation of such a drug would necessarily increase our understanding of sexual motivation. Even if there’s not a disorder to be treated researching it doesn’t seem like an absurd proposition.

  9. I love you sci!!!

  10. I love you sci!!!

  11. I love you sci!!!

  12. Good points all around Sci.
    I can’t remember where the literature was (maybe check Mind Hacks?) but I remember reading something last year that even ED is not always physiological in nature (though in many cases it is for, as you mentioned, the physical structure such as it is). But if you have something that forces a stiffy on you, then you don’t have to do the psychological work to actually deal with your desire and get one naturally.
    There’s nothing that can make the same effect on women as far as I know, and I think what this failed study shows is that it’s awfully sketchy to be looking for a physiological cause.
    It would be more productive, I think, to address what I think is the general repression of sexual desire in people – not just women. But in women this repression is devastating. Think about all the factors in life that can kill desire and get in the way of letting emotions flow naturally. I think that is the problem, not something wrong with a woman’s body. In that sense this study reinforces hundreds of years of discrimination by trying to highlight a physical problem in women rather than address an emotional reaction.
    Of course this solution is much more difficult to address because it involves changing big patterns in our whole f*cked up society, what people do and expect of themselves.
    I like how you bring up desire, which is a big interest to me because it takes many shapes. Desire can be specifically for a person, for an experience in general, for a kind of experience. It can be sexual or not and is conjured up by various kinds of emotional experiences. If I introspect, I can say I experience some kind of desire dozens of times a day. And if someone is not feeling any desire for anything, then there is no chance that they will act on the urges desire brings, and there is no chance for satisfaction.
    One can imagine a scenario involving Viagra, where a man will take it because of the expectations and pressures of having to perform an obligation. Desire could not be involved at all, and men’s emotional lives are generally glossed over in favour of the physical reaction, which is so easy and quantifiable.

  13. Good points all around Sci.
    I can’t remember where the literature was (maybe check Mind Hacks?) but I remember reading something last year that even ED is not always physiological in nature (though in many cases it is for, as you mentioned, the physical structure such as it is). But if you have something that forces a stiffy on you, then you don’t have to do the psychological work to actually deal with your desire and get one naturally.
    There’s nothing that can make the same effect on women as far as I know, and I think what this failed study shows is that it’s awfully sketchy to be looking for a physiological cause.
    It would be more productive, I think, to address what I think is the general repression of sexual desire in people – not just women. But in women this repression is devastating. Think about all the factors in life that can kill desire and get in the way of letting emotions flow naturally. I think that is the problem, not something wrong with a woman’s body. In that sense this study reinforces hundreds of years of discrimination by trying to highlight a physical problem in women rather than address an emotional reaction.
    Of course this solution is much more difficult to address because it involves changing big patterns in our whole f*cked up society, what people do and expect of themselves.
    I like how you bring up desire, which is a big interest to me because it takes many shapes. Desire can be specifically for a person, for an experience in general, for a kind of experience. It can be sexual or not and is conjured up by various kinds of emotional experiences. If I introspect, I can say I experience some kind of desire dozens of times a day. And if someone is not feeling any desire for anything, then there is no chance that they will act on the urges desire brings, and there is no chance for satisfaction.
    One can imagine a scenario involving Viagra, where a man will take it because of the expectations and pressures of having to perform an obligation. Desire could not be involved at all, and men’s emotional lives are generally glossed over in favour of the physical reaction, which is so easy and quantifiable.

  14. Maybe someone should ask single women (not in a relationship), who masturbate and feel perfectly OK and happy about doing so, how often they need to do it, on average, and what makes them want it more or less.
    Perhaps only that could give some sort of “raw” data about desire for sex/orgasm/release of sexual tension (not a particular man, a cuddle, a baby etc), because in relationships that’s quite a complex thing and sexual desire or the lack of it might be influenced by a huge number of partly or completely nonsexual factors (a lot of them being subconscious).
    I guess the main market for flibanserin sort of drugs would be women experiencing a complete loss of libido while on oral contraceptives. It’s a massive problem for a lot of women. Sometimes they spend months to adjust to the hormones in the pill, considered by many the best method for contraception and what they get is zero desire for sex.

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