Addyi (Flibanserin): Uses, dosage, side effects, warnings & patient reviews

What is Addyi (Flibanserin)?

Addyi is a daily prescription tablet containing the active ingredient flibanserin. It is classified as a multifunctional serotonin receptor agonist and antagonist. Unlike medications for erectile dysfunction that affect blood flow, Addyi acts on neurotransmitters in the brain to help increase sexual desire in women diagnosed with HSDD (Hypoactive Sexual Desire Disorder).

Addyi was originally studied as an antidepressant before its application for low sexual desire was discovered. For more on how medications can affect brain chemistry, you can read this guide to antidepressants. The medication is intended for use only by premenopausal women and requires a careful assessment by a healthcare provider to confirm the diagnosis of HSDD.

It is important to understand that Addyi is not a hormone therapy and does not work immediately. It is taken daily at bedtime, and it may take several weeks of consistent use to notice an effect.

How to Take Addyi

Addyi has a specific administration protocol designed to maximize safety and effectiveness. Strict adherence to these instructions is crucial.

Dosage and Timing

The standard Addyi dosage is 100 mg, taken orally once daily at bedtime. Taking it at bedtime is critical to help reduce the impact of its most common side effects—drowsiness and dizziness. Do not take more than one tablet in 24 hours.

Course of Treatment

Addyi must be taken consistently every day to be effective. It is not an “as-needed” medication. Clinical studies show that some women may begin to notice an improvement in sexual desire after 4 weeks of daily use, with further improvement potentially occurring at 8 weeks and beyond. Do not stop taking Addyi without consulting your doctor.

Important Precautions

• Bedtime Dosing: Always take Addyi at bedtime to minimize the risk of injury from dizziness or fainting.
• Consistency: Take it at approximately the same time each night to maintain steady levels in your system.
• Assessment: Your doctor should reassess your condition after 8 weeks of treatment to determine if Addyi is providing benefit.

Side Effects of Addyi

The side effects of Addyi are primarily related to its action on the central nervous system. Most are mild to moderate, but some can be serious.

For a broader understanding of how medications can cause drowsiness and affect safety, see our resource on medicines and drowsiness.

What is Addyi Used For?

Addyi has one primary, FDA-approved indication.

Treatment of Hypoactive Sexual Desire Disorder (HSDD)

Addyi uses are focused on treating acquired, generalized Hypoactive Sexual Desire Disorder in premenopausal women.

• Acquired means the low desire developed in a woman who previously had a normal level of sexual desire.
• Generalized means the low desire is not limited to a specific situation, partner, or type of sexual activity.

The condition must also cause personal distress. Addyi is intended to help increase the number of satisfying sexual events (SSEs) and boost sexual desire as measured by a daily diary.

Important Limitations

• Not for Men or Postmenopausal Women: Addyi is not approved for use in men or in women who have gone through menopause.
• Not for Sexual Dysfunction Due to Other Factors: It is not intended to treat low sexual desire that is due to a co-existing medical or psychiatric condition, relationship problems, or the side effects of another medication.
• Not an “On-Demand” Medication: Addyi is fundamentally different from drugs like sildenafil (Viagra). It is not taken before sexual activity and does not enhance physiological arousal or orgasm. For information on “as-needed” treatments for women, you can learn about Female Viagra or read about the differences between these treatments.

Important Safety Concerns and Considerations

Risk of Hypotension and Syncope

The most serious safety concern with Addyi is its potential to cause severely low blood pressure (hypotension) and fainting (syncope). This risk is significantly increased by concomitant use of alcohol or moderate/strong CYP3A4 inhibitors. Symptoms can include dizziness, lightheadedness, and loss of consciousness. This is why strict avoidance of alcohol and careful medication review are non-negotiable requirements for treatment.

Central Nervous System Depression

Addyi acts on the central nervous system and can cause sedation and somnolence. When combined with other CNS depressants (e.g., certain benzodiazepines, opioids, sleep aids), the depressive effects can be additive, leading to dangerous levels of sedation, respiratory depression, or coma.

Liver Enzyme Interactions

Flibanserin is primarily metabolized by the liver enzyme CYP3A4 and to a lesser extent by CYP2C19. This makes its blood levels highly susceptible to interactions with other drugs that induce or inhibit these pathways. Co-administration with strong CYP3A4 inhibitors is contraindicated.

Use in Patients with Liver Impairment

Addyi is not recommended for use in patients with hepatic impairment (Child-Pugh Class B or C). The drug’s metabolism is reduced, leading to higher exposure and an increased risk of adverse effects, including hypotension and syncope.

Critical Warnings for Addyi Use

Alcohol Contraindication

Addyi must never be taken with alcohol. This is an absolute contraindication. The interaction can lead to profound hypotension, syncope, and CNS depression, which may result in injury. Patients must be alcohol-free before starting Addyi and must commit to complete abstinence during treatment.

Hypotension and Syncope Warning

Addyi can cause hypotension and syncope even in the absence of alcohol. The risk is increased in patients taking other medications that lower blood pressure. Patients should be advised to rise slowly from a sitting or lying position to minimize symptoms of orthostatic hypotension.

CNS Depression Warning

Addyi can cause significant somnolence. Patients should be cautious about engaging in activities requiring full mental alertness, such as driving, for at least 6 hours after each dose or until they know how the drug affects them. Concurrent use with other CNS depressants increases this risk.

Drug Interaction Warning

Concomitant use of Addyi with strong or moderate CYP3A4 inhibitors is contraindicated. This includes common medications like fluconazole (Diflucan), certain antibiotics (e.g., clarithromycin), and some HIV and hepatitis C medications. Concomitant use with CYP3A4 inducers may reduce flibanserin efficacy.

Addyi Dosage Information

The dosage of Addyi is fixed and must be followed precisely as prescribed.

Important Administration Notes

• Missed Dose: If you miss a dose at bedtime, skip it. Do not take two tablets the next day to make up for the missed dose. Resume your regular schedule the following night.
• Assessment of Benefit: Your doctor will evaluate whether Addyi is working for you after 8 weeks of daily use. Do not continue the medication if no benefit is seen after this period, unless advised by your doctor.
• Discontinuation: There is no need to taper the dose when stopping Addyi. However, you should always consult your doctor before discontinuing any prescription medication.

Drug Interactions with Addyi

Addyi has numerous potentially serious drug interactions due to its metabolism via the CYP3A4 pathway and its CNS effects.

Additional Information

Storage and Handling

Store Addyi tablets at room temperature between 20°C to 25°C (68°F to 77°F), in a tightly closed container, away from light, excess heat, and moisture. Keep all medications out of the reach of children and pets.

Obtaining Addyi Safely

Addyi is a prescription-only medication available through certified pharmacies. Due to its serious risks (especially the Addyi alcohol interaction), it is only available through a restricted program called the Addyi REMS Program. Doctors and pharmacies must be certified in this program to prescribe and dispense the drug. Patients must also be counseled on the risks and sign an acknowledgment form. Purchasing Addyi from unverified online sources is extremely dangerous. For guidelines on safe purchasing, see our article on buying medicines online safely.

Reporting Side Effects

You are encouraged to report negative side effects of prescription drugs to the relevant national health authority (e.g., the FDA in the United States). Reporting helps health authorities monitor drug safety and identify new risks.

References and Medical Sources

The information on this page is compiled from reputable medical sources and prescribing information.

1. U.S. Food and Drug Administration (FDA). Addyi (flibanserin) Prescribing Information, including Boxed Warning. [Updated 2015]. https://www.accessdata.fda.gov/drugsatfda_docs/label/2015/022526lbl.pdf
2. MedlinePlus. Flibanserin. U.S. National Library of Medicine; [Updated 2020]. https://medlineplus.gov/druginfo/meds/a615045.html
3. American College of Obstetricians and Gynecologists (ACOG). Clinical Practice Guideline: Female Sexual Dysfunction. [Published 2022].
4. Drugs.com. Flibanserin Professional Monograph. Drugs.com; [Updated 2024]. https://www.drugs.com/monograph/flibanserin.html

Disclaimer: The information on this site is provided for informational purposes only and is not medical advice. It does not replace professional medical consultation, diagnosis, or treatment. Do not self-medicate based on the information presented on this site. Always consult with a doctor or other qualified healthcare professional before making any decisions about your health.