Photo by Aiony Haust

Introduction to the Market

In 2013, the drug was re-introduced and rejected again, as randomized clinical trials demonstrated its effects were no better than placebo and could potentially pose serious safety concerns.

Finally, in 2015, Addyi was approved after the company Sprout took over and convinced the FDA to allow changes in the way Addyi’s effectiveness was measured. The drug for women faced flurries of condemnation from both consumers and those in the medical community.

Clinically known as "flibanserin," Addyi was created with the intent to treat women suffering with HSDD (hypoactive sexual desire disorder), which is a condition in which a woman experiences a low libido.

The Effects

Unlike Viagra, however, which dilates blood vessels and increases blood flow to the penis so that men can keep an erection long enough to enjoy sex, Addyi alters brain chemistry. With a daily dose, the drug targets the brain's neuroreceptors to enhance serotonin release and dopamine levels in the brain.

Unfortunately, that's not all it does. Common side effects described among the 2,997 women who were treated with flibeanserin in clinical trials included dizziness, headaches, fatigue, somnolence, and nausea.

Taken in high doses or with alcohol, the sedative effects also caused dangerously low blood pressure. It was later recommended that women taking it should not drink alcohol, which poses an issue given that women expecting to benefit from the drug must take it daily. Implementing Addyi is, thus, a lifestyle commitment.

The Studies

A follow-up study on the use of alcohol in combination with flibanserin found that having two to four drinks (defined as 1.5 ounces of alcohol) caused unconsciousness and even concussions, in addition to the previously noted drop in blood pressure.

The study was conducted on 23 men and only two women. This, as noted by Yale School of Medicine, "makes very little sense, given that the drug is specifically designed for use by women. The study results are particularly problematic, since women absorb more alcohol in their blood when they drink the same amount as men, and so experience alcohol's effects faster than men."

The issues with pre-market evaluations don't end there.

Photo by Hanna Postova

Many, including the National Women's Health Network (NWHN), took issue with exclusion criteria of the three primary drug trials as they didn't provide an accurate assessment of female desire on the whole.

Reports from clinical trials assessing the efficacy of the drug noted that "women [tested] were required to be in a monogamous heterosexual relationship of at least one year." Exclusion criteria also included diagnoses of sexual dysfunction other than HSDD, psychiatric disorders, major depressive disorders, and psychological therapy.

Not all women are in heterosexual, long-term relationships. Not all women are mentally stable without medications nor can they afford to abandon such medications in pursuit of sexual desire. Adding insult to injury, the results of pre-market trials revealed 10% effectiveness.

Among that 10% of women who responded positively to the drug, an average increase of between .5 and .7 "sexually satisfying events" per month was reported.

For a drug that requires daily intake, mandates sobriety, causes significant side effects, and reportedly requires eight weeks to take effect, one must question whether an extra .5 to .7 sexual experiences per month is worth the cost.

A Complex Issue

Science will continue to investigate new ways to treat HSDD, but lack of libido, especially in women, is a complex topic. The Yale School of Medicine wrote to this effect, explaining "many experts believe that a women's libido reacts got social, emotional, biological, and psychological conditions rather than representing a regular baseline of sexual arousal."

In its FDA application, Sprout admitted they did not know the exact mechanism by which the drug might work.

The pharmaceutical industry, however, continues striving to medicalize women’s loss of libido, branding it a health-related dysfunction that needs to be fixed with a pill, rather than lifestyle changes that address greater underlying issues.

In addition to Addyi, there is a new pre-menopausal drug for patients with low libido called Vyleesi. The injectable medication, like Addyi, is meant to treat people with hypoactive sexual desire disorder (HSDD). 

Addyi Versus Vyleesi

As noted, Vyleesi is administered via injection into the thigh or abdomen. Addyi, on the other hand, is a daily oral pill.

Vyleesi trials noted that most patients used the drug two to three times per month and no more than once a week. It's intended to be taken 45 minutes before intercourse and has not demonstrated dangerous side effects when taken with alcohol.

The results of trials were consistent with findings in Addyi trials in terms of effectiveness. Vyleesi did not yield significant change in libido in women tested. Listed side effects included sleepiness and fainting.

In a clinical trial, forty percent of the participants experienced nausea—a burden that may put a damper on physical intimacy. Participants of the study also had darkened spots on their gums and skin, which did not go away.

It's evident that Vyleesi isn't the final solution for Addyi's failings. The drug's entrance into public dialogue may, however, lead to further research and more optimal options for those struggling with low libido. 

Photo by Sabina Tone

Two decades ago, medical professionals helped men overcome their sexual disorders while women faced issues of decreased libido in silence. But the question remains: is increased sex drive merely a matter of blood flow?

All signs point to "no."

For now, the fight for female equality wages on, so too does the pursuit of equally-effective libido treatment methods—regardless of whether the person medicating has a penis or a cervix.

Drugs like Vyleesi and Addyi are just more names on a roster of ways big pharma promotes solutions to something that doesn’t have one simple answer.