Short answer: In the label's trials in premenopausal women, the most common Addyi side effects were dizziness (11.4% vs 2.2% on placebo), sleepiness (11.2% vs 2.9%), nausea (10.4% vs 3.9%) and fatigue (9.2% vs 5.5%), mostly starting in the first 14 days. Addyi has a boxed warning: severe low blood pressure and fainting with alcohol close in time, some medicines, or liver problems.
What Addyi is approved for: Addyi is approved for women under 65 with acquired, generalized hypoactive sexual desire disorder (HSDD): low sexual desire that causes marked distress or relationship difficulty, began after a time without such problems, and is not due to another medical or mental health condition, relationship problems, or a medicine or drug (section 1). It is not for men and not for enhancing sexual performance.
Source
ADDYI (flibanserin) tablets, for oral use, prescribing information and Medication Guide. Sprout Pharmaceuticals. DailyMed, version published December 23, 2025. DailyMed setid 3819daf3-e935-2c53-c527-e1d57922f394
WARNING: HYPOTENSION and SYNCOPE IN CERTAIN SETTINGS
Taking Addyi and alcohol close together raises the risk of severe low blood pressure and fainting. The label says to wait at least two hours after one or two standard drinks before the bedtime dose, or to skip that night's dose after three or more drinks. Moderate or strong CYP3A4 inhibitors raise flibanserin levels and can cause severe low blood pressure and fainting, so they are contraindicated with Addyi. Addyi is also contraindicated with any liver impairment for the same reason.
These are the label's own numbers from the Adverse Reactions section. Where the label compares with placebo (a dummy treatment), both columns are shown, so you can see how much more often a reaction happened on Addyi.
| Adverse reaction | Premenopausal Placebo (N=1556) | Premenopausal ADDYI (N=1543) | Postmenopausal Placebo (N=797) | Postmenopausal ADDYI (N=801) |
|---|---|---|---|---|
| Dizziness | 2.2% | 11.4% | 3.3% | 7.9% |
| Somnolence | 2.9% | 11.2% | 1.8% | 7.7% |
| Nausea | 3.9% | 10.4% | 3.9% | 6.6% |
| Fatigue | 5.5% | 9.2% | 3.9% | 3.0% |
| Insomnia | 2.8% | 4.9% | 3.4% | 5.7% |
| Dry mouth | 1.0% | 2.4% | 1.3% | 2.4% |
| Urinary tract infection | 2.4% | 2.3% | 3.0% | 3.2% |
| Anxiety | 1.0% | 1.8% | 1.6% | 2.6% |
| Sinusitis | 3.5% | 2.9% | 2.1% | 2.5% |
| Constipation | 0.4% | 1.6% | 1.8% | 2.5% |
Reactions in at least 2% on Addyi 100 mg at bedtime and more often than on placebo. Premenopausal trials were Studies 1 to 4 (24 weeks); postmenopausal trials were Studies 6 and 7, in women under 65. Most began within the first 14 days.
| Adverse reaction | Premenopausal Placebo (N=1556) | Premenopausal ADDYI (N=1543) | Postmenopausal Placebo (N=797) | Postmenopausal ADDYI (N=801) |
|---|---|---|---|---|
| Overall | 6% | 13% | 5% | 9% |
| Dizziness | 0.1% | 1.7% | 0.3% | 0.9% |
| Nausea | 0.1% | 1.2% | 0.3% | 0.5% |
| Insomnia | 0.2% | 1.1% | 0.5% | 1.4% |
| Somnolence | 0.3% | 1.1% | 0.1% | 0.6% |
| Anxiety | 0.3% | 1% | 0.6% | 1.2% |
Reactions that led more than 1% of women on Addyi 100 mg at bedtime to stop, and more often than on placebo, in the pooled trials.
Sleepiness, sedation or fatigue together: 21% on Addyi vs 8% on placebo in premenopausal women, and 10% vs 6% in postmenopausal women under 65.
Without alcohol or interacting medicines, in premenopausal trials low blood pressure was 0.2% vs under 0.1% on placebo, and fainting 0.4% vs 0.2%.
In a study of 100 mg Addyi taken at the same time as alcohol equal to about two drinks, 4 of 23 healthy people (17%) had low blood pressure or fainting needing treatment, with systolic drops of 28 to 54 mmHg.
With fluconazole (a moderate CYP3A4 inhibitor), 3 of 15 healthy people (20%) had low blood pressure or fainting, and one became unresponsive at 64/41 mm Hg; flibanserin exposure rose 7-fold and the study was stopped.
Women using hormonal birth control had more dizziness (13.4% vs 9.9%), sleepiness (12.3% vs 10.6%) and fatigue (11.4% vs 7.5%) on Addyi than non-users. Appendicitis was reported in 0.2% on flibanserin and none on placebo.
Reported after approval: allergic reactions including anaphylaxis and swelling, vomiting, weakness, feeling drunk or abnormal, headache, near-fainting, unsteady walking, blurred vision and brain fog.
The Warnings and Precautions part of the label lists these. Each line gives the label's heading and what it means in plain words.
Low blood pressure and fainting with alcohol. Taking Addyi within two hours after drinking raises the risk of severe low blood pressure and fainting. The label says to wait at least two hours after one or two standard drinks before the bedtime dose, skip the dose after three or more drinks that evening, and not drink after taking Addyi until the next day. One standard drink is 14 g of alcohol.
CYP3A4 inhibitors. Moderate or strong CYP3A4 inhibitors (such as ketoconazole, fluconazole, ritonavir, clarithromycin, diltiazem, verapamil and grapefruit juice) sharply raise flibanserin levels and are contraindicated. Several weak inhibitors together, including ginkgo, resveratrol or cimetidine, may also raise levels.
Sleepiness and sedation. Addyi can cause sleepiness, more so if taken while awake or with alcohol, other sedating drugs or CYP3A4 inhibitors. The label says to avoid driving or operating machinery until at least 6 hours after a dose and until people know how Addyi affects them.
Low blood pressure and fainting with Addyi alone. Addyi alone can cause low blood pressure and fainting, more so if taken while awake or above the recommended dose. Someone who feels faint should lie down right away and get help if it does not pass.
Liver impairment. Any degree of liver impairment raises flibanserin levels about 4.5-fold, so Addyi is contraindicated in liver impairment.
Allergic reactions. Anaphylaxis, angioedema-type swelling of the face, lips and mouth, itching and hives have been reported. Addyi is stopped at once if a reaction occurs.
Mammary tumors in female mice. A 2-year study found more malignant breast tumors in female mice at 3 and 10 times the clinical exposure, but not in male mice or rats. The clinical significance is unknown.
From the Medication Guide that comes with Addyi:
Dose Track has a side-effect log. Each entry records the symptom, a severity (none, mild, moderate, severe or life-threatening), the date and an optional note, and can be tied to a specific dose or logged on its own. The history screen shows what you logged over time, which makes it easier to tell your prescriber when a reaction started and whether it is easing. The app records what you enter; it does not judge whether a symptom is serious. For anything on the label's call-your-doctor list, call your doctor.
This page is what the FDA label says, in plain words. It is not medical advice. Follow your prescriber, and ask them or your pharmacist about anything here.