Flibanserin: what it treats, how to take it, side effects
Last updated September 3, 2026.
Flibanserin (brand name Addyi) is a daily bedtime pill for acquired, generalized hypoactive sexual desire disorder (HSDD) in women under 65. It works on brain chemistry rather than blood flow, and it carries a boxed warning about low blood pressure and fainting, especially around alcohol.
What does it treat?
It treats HSDD: low sexual desire that causes real distress or relationship strain, is not explained by another medical or psychiatric condition, relationship problems, or another drug, and has been acquired (there was a time desire was normal). It is not indicated for men and not a performance enhancer. Set expectations honestly: the average benefit in trials was modest, some users notice no change, and the label says to stop if 8 weeks bring no improvement.
How do you take it?
One 100 mg tablet at bedtime, every day. Bedtime dosing is a safety feature: taken during waking hours it raises the risk of low blood pressure, fainting, and sedation. The alcohol rules are specific. Wait at least 2 hours after 1 or 2 standard drinks before taking your bedtime dose; if you have had 3 or more drinks that evening, skip the dose; and after a dose, no alcohol until the next day. If you miss the bedtime dose, skip it; never take it in the morning or double up. Avoid driving or machinery for at least 6 hours after a dose until you know how it affects you.
Side effects to know
- Common: dizziness, sleepiness, nausea, fatigue, insomnia, dry mouth, constipation, anxiety, and sinus or urinary infections, each in at least 2% of users.
- Serious: hypotension and fainting, the boxed-warning risk, worst with alcohol, with certain drug interactions, or with liver problems. If you feel faint, lie down flat right away and seek medical help if it does not resolve quickly.
Who should not take it?
Do not combine flibanserin with moderate or strong CYP3A4 inhibitors (certain antifungals, antibiotics, and others) or take it with any liver impairment; both are contraindications. It is not recommended while breastfeeding. Oral contraceptives and other weak CYP3A4 inhibitors raise flibanserin levels and side effects, so your prescriber needs your full list, including supplements. Heavy alcohol use is effectively incompatible with this drug.
When is it an emergency?
Call 911 for fainting that does not resolve quickly when lying flat, or for signs of anaphylaxis: hives with swelling of the face or throat or trouble breathing. Lightheadedness that resolves on lying down still deserves a same-day call to your prescriber. Pymander's escalation routing is built and tested specifically for this class of decision; see the safety architecture working paper.
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Common questions
How well does flibanserin actually work?
Modestly, on average, and it is fair to know that up front. In the approval trials, users gained on the order of one additional satisfying sexual event per month over placebo, with some responding well and others not at all. The label itself says to stop if 8 weeks of nightly use bring no improvement.
Why is it called "female Viagra," and is that accurate?
The nickname is catchy but wrong. Viagra affects blood flow and is taken as needed before sex. Flibanserin adjusts brain neurotransmitters (serotonin, dopamine, norepinephrine) and is taken daily for weeks before any effect shows. It targets desire, not arousal mechanics.
What are the exact alcohol rules?
From the label: wait at least 2 hours after 1 or 2 standard drinks before your bedtime dose; if you have had 3 or more drinks that evening, skip the dose entirely; and after taking it, no alcohol until the next day. Ignoring these raises the risk of severe low blood pressure and fainting.
Why must it be taken at bedtime?
Because its main dangers, low blood pressure, fainting, and sedation, are worst in the hours after a dose. Sleeping through that window is the safety plan. Taking it in the morning is not a workaround for a missed dose; the label says skip and take the next dose the following night.
Who is flibanserin NOT for?
Men, anyone whose low desire traces to a medication (some antidepressants do this), relationship problems, or another medical condition, and anyone with liver impairment or on strong CYP3A4-inhibiting drugs. It is also not recommended while breastfeeding. Sorting the cause of low desire comes first.
Can I take it with my antidepressant or birth control?
Both need a prescriber's review, not a yes from the internet. Oral contraceptives raise flibanserin levels and side effects, and if low desire began with an SSRI, the drug is not indicated for that situation. Bring the full list, including supplements, to the visit.