Pepper Schwartz is professor of sociology at the University of Washington and the author of many books, the latest of which is " The Normal Bar. " She is the love and relationship ambassador for AARP and writes the Naked Truth column for AARP.org. She is also a senior fellow at the Council on Contemporary Families , a nonprofit organization that gathers research on American families. The opinions in this commentary are solely those of the author.

(CNN) Does she really have a headache? And if not, could a little pink pill help?

For the most part, we know that for many women, the only "headache" that is causing her to avoid sex is fatigue or relationship issues. (If it were George Clooney asking for sex, that headache might miraculously disappear.)

But I don't believe that being tired or out of sorts are the only reasons women lose desire.

Which is why the Food and Drug Administration announcing its approval this week of a "female Viagra" is intriguing -- and appealing: the idea that a pill could restore libido in women, just the way Viagra has improved the hydraulics for millions of men.

The move came after an organization recently launched a pressure campaign , backed in part by the drug's developer, to push the FDA for approval, saying gender bias has kept such a pill from women.

It's a complicated issue, no question. But some women are genuinely upset about their loss of libido. They are searching for help and deserve to have it.

In so many sexuality and relationship workshops I have conducted with women, I have heard the following lament: "I love my husband. I used to crave making love with him. But now I feel nothing. I wish I could reclaim my sexual desire and sexual pleasure." In these cases I don't think it's the relationship that's the issue, or having a partner who is sexually inept, or the effect of memories from earlier sexual trauma. No, something else is going on.

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That said, it is not clear what will help a woman who lacks desire and has little ability to be aroused. Consider: Early clinical trials for Viagra to see if it would stimulate women's sexual desire didn't do so well. One study by psychologists Andrea Bradford and Cindy Meston found that if women thought they were taking a sexual arousal drug but were instead taking a placebo, they still reported a rise in libido. These authors found an almost uniform rise in libido, particularly if the women were in a long relationship.

The "placebo effect" is powerful -- so powerful that it is difficult to get the FDA to pass any drug because, quite reasonably, a new medication needs to be more effective than the results that occur in the placebo control group. This was initially believed to be the case with flibanserin, the desire drug that will be sold as Addyi.

Furthermore, even some of the people on the FDA advisory committee who voted in June to recommend the drug's approval were worried that the results were small and side effects worrisome, although not huge (mostly nausea and fainting). Dr. Julia Heiman, a respected psychologist and past head of the Kinsey Institute, once joked with me that she sometimes wished it was possible to sell a placebo as the real thing because then you could get the same results for a lot of people without any side effects.

But the fierce fight between advocates of a desire drug and doctors and psychologists who believe that the approval of flibanserin creates a pathological condition where none exists is no laughing matter. One side hopes for a pill to help solve desire problems; the other looks to natural attenuation of desire or to psychological and relationship issues.

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The fact remains that there is medical evidence that not all desire is impeded by interpersonal or intrapersonal issues. We know, for example, that "stress hormones" make sexual desire unlikely. We also know that many modern medications, for example anti-depression drugs or drugs used to treat heart disease, cancer and diabetes, will affect desire and sexual ability -- so why is it unthinkable that some women's current physiological functioning impedes sexual response? And could be helped with medicine?

I know this has become a feminist issue. But interestingly enough, there are feminists on both sides of the debate: Some support the idea of a pill, and believe that women deserve a desire drug, and others feel this is just another plot to label women as dysfunctional when there is evidence that losing sexual desire over the life cycle may be a natural consequence of hormonal change that doesn't need to be fixed.

I get both sides, but I have landed on the former. Even if loss of sexual desire is normal in some women, it is not optimal. I am not, for example, as physically strong as I used to be, but I know if I work out I can be stronger than if I don't. Am I rejecting nature? Correct: I am. Nature may take us some places we don't want to go -- and if an exercise regimen, a pill or even a tummy tuck (not done yet, but I would consider it!) help us resist changes we do not want to accept, I'm all for it.

Up to a point. Any new regimen has to be safe and effective.

I presume that the FDA decided that the benefits were high enough, and the side effects low enough, to approve the drug. The "pill" has to work better than a placebo, and the side effects have to be reasonable and unlikely. I understand that there are some side effects, but let's face it, nothing is cost-free and most women who yearn for their lost desire would likely be happy to take on moderate costs to jump-start their sex lives.

For myself, the capacity for sexual desire is an important part of my identity and my pleasure in life. If it were ever to go away spontaneously, I will be first in line for that little pill.