Consumer Health Info

Top 10 Things to Know About Today’s Sex Drive Drugs

Publication Date: October 15, 2015

By: Rachel Grimsley, (RN, BSN, MSN) Volunteer Health Officer

Learn about Addyi (flibanserin) and Vyleesi (bremelanotide), FDA-approved drugs designed to treat hypoactive sexual desire disorder (HSDD) in premenopausal women to improve sex drive.

1. Neither of These Drugs Is a “Viagra for Women.”

Though both medications have taken their turns being dubbed the “female Viagra” in media reports, they are very different from the little blue pill. Viagra helps men who already want to have sex but are not able to physiologically. It is taken on an as-needed basis to help increase blood flow to the penis.

In contrast, Addyi works on the brain in women to help them want to have sex and it must be taken every day. Vyleesi, while taken on an as-needed basis, is an injection that targets brain hormones to try and increase a woman’s sexual desire.

2. Addyi and Vyleesi Were Tested in Narrow Subsets of Women.

The participants who enrolled in the initial clinical trials for Addyi were premenopausal, heterosexual, and generally healthy women. In four of the trials, an overwhelming majority of these participants identified as White (89%). In three trials, 78% were married, 74% of participants had never smoked. For Vyleesi, 86% of participants were White, and those taking common blood pressure or depression medications were excluded from the study. Given the general exclusion criteria and demographic information for the trials, the extent to which the results can be generalized to the public is limited.

3. The Affects Are Minimal for Most Women

After adjusting for placebo, an FDA review found only 8-13% of women in clinical trials benefited-and minimally-from taking Addyi. For this small subset of women, the minimal benefits of taking Addyi were felt by about eight weeks. This means women shouldn’t keep taking Addyi beyond eight weeks if they do not experience an improvement in sexual desire by that point.

Similarly, in clinical trials for Vyleesi, 8% of women experienced an increase in sexual desire as a result of the drug.

4. Addyi May Cause Sudden Prolonged Unconsciousness. Vyleesi May Cause Severe Nausea.

Addyi can depress the central nervous system. During clinical trials, women who used Addyi were more likely to experience dangerously low blood pressure, dizziness, and loss of consciousness than women taking placebo. These studies also revealed a higher incidence of accidental injury in women taking Addyi, especially if alcohol was consumed within two hour of taking it.

For women taking Vyleesi, nausea was the most common adverse effect. Thirteen percent (13%) needed medications for the treatment of nausea. Other effects include facial, gum, or breast darkening. Vyleesi can also raise someone’s blood pressure but lower their heart rate.

5. Alcohol Should Be Largely Avoided When Taking Addyi, but a Few Drinks May Be Safe When Taking Vyleesi.

Women may experience fatigue, low blood pressure, and fainting when using Addyi, which may be exacerbated when drinking alcohol. As of April 2019, the FDA advises women to stop drinking alcohol two hours before their daily bedtime dose of Addyi and to not consume alcohol until 8-10 hours later based on post-marketing studies run by the company. The FDA considers this risk important enough to mandate a black box warning about potentially dangerous low blood pressure and fainting, especially when taken with alcohol.

In a small study, taking Vyleesi at the same time as drinking alcohol (the equivalent of 3 glasses of wine) didn’t cause any ill effects.

6. Hormonal Contraceptives May Interfere With Addyi and Vyleesi.

Using Addyi while on hormonal contraceptives may cause additional side effects. Some adverse events, including sleepiness, dizziness and fatigue, were reported more often in women who used hormonal contraceptives. Hormonal contraceptives are known to affect a certain enzyme (CYP3A4), which may increase Addyi exposure by 40%.

Women taking hormonal contraceptives together with Vyleesi didn’t see a statistically meaningful rise in sexual desire. However, when taking Vyleesi, women’s bodies still absorbed common contraceptive hormones in a typical way.

7. Addyi and Vyleesi May Interfere With Other Common, Everyday Medications.

Many commonplace medications are CYP3A4 inhibitors and may significantly increase a body’s exposure to Addyi. This could lead to poor tolerability of the drug, as well as increases in low blood pressure and fainting for women using Addyi. These medications include antiepileptic drugs, benzodiazepines, antidepressants, antipsychotics, mood stabilizers, narcotics, vaginal lubricants, and even St. John’s wort, all of which were excluded from initial studies.

Vyleesi interacts with everyday treatments for those struggling with substance use disorder (e.g. naltrexone), and may slow down the absorption of other drugs, making them ineffective (e.g. antibiotics, pain medications).

8. Neither Drug Is Designed to Address Ability to Orgasm or Quality of Sex.

These two drugs belong to a class of drugs that has sedative properties, known as serotonin 1A receptor agonists and serotonin 2A receptor antagonists that affect brain chemistry to increase the desire for sex, or libido, in premenopausal women. Neither is designed to make achieving orgasm easier nor do they necessarily make sex more enjoyable for either partner. Addyi was not developed to enhance sexual performance or help all women have a better sex life. It is only licensed for premenopausal women who are diagnosed with Hypoactive Sexual Desire Disorder.

9. the FDA Recommends Some Changes for Companies Developing Sex Drive Drugs, but Misses the Larger Question: Is This the Best Way to Help Women?

In 2016, the FDA published soft-ball draft guidance for companies developing sex drugs for women. The guidelines recommend that companies test different doses, justify each distinct drug component, create interpretable study results, and complete adequate safety assessments. The FDA no longer requires companies to show that their sex drugs for women result in more sex – perhaps because no drug reviewed by the FDA has been able to pass that test.

The FDA does not challenge or discuss whether sexual dysfunction is as widespread as manufacturers claim and whether a drug is the best way to address low libido in women.

10. Alternatives to Sex Drive Drugs

While Addyi is advertised as “the female Viagra,” clearly it is not. Women must be premenopausal and diagnosed with HSDD to be prescribed most medications that are available to help with sexual desire.  

The safest place to start looking for alternatives to Addyi is with your doctor. Start the conversation by stating what the problem is. There could be another medical condition that your doctor can help diagnose and treat, or they may recommend a local therapist with glowing reviews. So, if you are experiencing trouble in the bedroom, start by discussing it with a professional. They might recommend:  

  • Talking to a sex therapist for counseling. 
  • Cognitive-behavioral therapy, mindfulness meditation therapy, and couples therapy.  
  • Reading books like Come as You Are by Dr. Emily Nagoski takes a neuroscience lens to libido and understanding one’s relationship to one’s body and sexual experiences.  

Help consumers! Report problems with sex drive drugs.

If you experience a problem, side effect, or other adverse reaction after taking Addyi or Vyleesi, consider reporting it at MedWatch, the FDA’s reporting system for drugs and medical device adverse events.

Report a Problem

Edited 11/30/2023 by Rachel Grimsley, RN, BSN, MSN, Nurse Writer

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