Lots of pharmaceutical companies want to make drugs targeting women who have low sex drives or trouble becoming aroused. And now, the Food and Drug Administration has new guidelines these companies should follow.

The new draft guidelines come a year after the administration approved the so-called “female Viagra”: a drug called Addyi that promised to make women want sex more. The decision was controversial, and many opponents said that side effects like dizziness and nausea outweighed the benefits. Women had to take the drug every day and couldn’t drink while taking it — and after all that, only 13 percent (at most) experienced the benefit of 0.5 more "sexually satisfying" events a month. (FDA spokesperson Andrea Fischer said that the administration’s decision on Addyi has not changed and that it still believes that Addyi’s benefits outweigh its risks.)

Future drugmakers targeting female desire now know what the FDA wants in the trials, and what results in the last of three phases of testing are likely to get their drug approved. These guidelines replace earlier ones that used now-outdated diagnostic information and didn’t include comments from a meeting the administration held two years ago about female sexual issues.

Sexual problems can’t be because of relationship issues

Female sexual dysfunction is a complicated topic because it’s caused by a combination of physical, psychological, and social issues — from stress to guilt about sex to hormonal imbalance. It’s very hard to say that dysfunction is caused only by one of these factors, says Kyle Stephenson, a psychologist who runs the Sexuality and Relationships Lab at Willamette University. So treating the dysfunction is more complicated than just taking a pill for it. “You can intervene in different ways — with a pill, in therapy, couples counseling — and many of those can eventually affect all of the factors,” he adds. “If you intervene with couples therapy, that should affect biology. If you intervene with a pill, that should affect psychology. It’s all interconnected.”

The new guidelines specify that subjects in clinical trials can’t present sexual problems caused by another medical condition, medicines taken for another condition, or problems within the relationship. This last point is one that many activists and scholars that study this issue find important. They argue that it’s perfectly reasonable to believe that women might have a low sex drive not because there’s something wrong with them, but because they’re in a bad relationship — and so it’s important to make sure we’re not using drugs to fix an interpersonal problem.

Measuring sex drive is very complicated

Some people are very wary of using drugs because a low sex drive can possibly be fixed with things like counseling. Mamta Mamik, a professor of gynecology at Mount Sinai Hospital, disagrees. “If you just medicate and don’t treat the other problems, it’ll be back to square one, but I disagree that medication should just be put under the rug,” she says. “We can’t say it’s always ‘just a psychological problem,’ it could be a real problem with a real solution and feel those women deserve chance to get treatment.” The discussion is similar to that around depression, she adds. Depression is another problem that many people think should be treated only with counseling and not anti-depressants.

Right now, one of the most common ways to measure sexual dysfunction is the Female Sexual Function Index (FSFI). It’s a survey that asks 19 questions, including “How often did you feel sexual desire?” and “How would you rate your level of sexual desire?” Though both Stephenson and Mamik say that the FSFI is probably the best scale we have, the FDA has doubts about whether it should be used by pharma companies.

First, the FDA is worried that some questions can lead to misleading scores. If someone taking a drug reports that they have more sexual fantasies than before, but don’t actually want more sex, their score will improve. But it probably won’t solve the problem they came in for. Another worry is that the survey will be inaccurate because it asks people to think back over the past month. Instead, the FDA recommends that women record their symptoms every day.

No scale is perfect because measuring sex drive is very complicated. It can be hard to separate subjective experience with physical indicators. One question on the FSFI asks how often a woman becomes “lubricated” during sex. Thing is, women with sexual dysfunction are often not very aware of their bodies, and so their self-report might be inaccurately low and lead to a focus on physical problems instead of encouraging women to notice their bodies more, says Stephenson.

“We need to develop a better scale. You need to look at everything, look at childhood events, individual factors, anything that may have happened in a relationship, physical factors,” says Mamik at Mount Sinai. “It should include a holistic perspective of a person, it should include all the causes that may cause problems, including guilt or anxiety — a lot of women feel guilty about sex and that’s a problem in causing arousal.”

There is already at least one other drug in the works to treat low sex drive

When it comes to outcomes, the guidelines say that success from a drug is measured by how much more sex, arousal, or “sexually satisfying events” (or how much less distress) a woman had compared to before. In the past, a lot of focus has been on the number of “sexually satisfying events,” but research suggests that it’s not a good measure because the frequency of sex can depend on so many external factors that don’t have to do with desire or distress, says Stephenson. “The real question for most of the researchers I’m familiar with, and certainly for me, is two primary points: level of desire and level of distress,” he says. If someone is happy with their subjective experience, even if they’re not necessarily feeling more sexual desire, then the job is done.

Finally, the drug should be tested in at least two trials that show it to be effective. People in the trial should be sexually active women over the age of 18, including menopausal women, who are in a stable relationship. The last factor makes it less likely that any improvement is because of the relationship itself improving, or because of a better partner.

Whether there’s an actual market for these drugs remains mostly conjecture. Very few people bought Addyi, which is made by Valeant, but other pharmaceutical companies remain interested in developing drugs that fix women’s sex drives. The FDA won’t comment on drugs until they are approved, but there is already at least one other drug in the works, called Palatin.

The public is welcome to comment on the new guidelines until December.

Rachel Becker contributed to this report.