Multifunctional serotonin agonist/antagonist (HSDD)
Flibanserin and grapefruit: a real interaction?
Grapefruit is famous as the juice that interacts with medications, and the warning is real for a number of drugs. Whether it matters specifically for Flibanserin (Flibanserin) at 100mg depends on whether the active ingredient Flibanserin is metabolised by CYP3A4 in the gut wall and how much that pathway contributes to first-pass metabolism.
The CYP3A4 mechanism
Grapefruit (and its juice) inhibits CYP3A4 enzymes in the gut wall, increasing the absorbed dose of medications metabolised by that enzyme. For drugs in the Multifunctional serotonin agonist/antagonist (HSDD) class that go through CYP3A4 first-pass metabolism, regular grapefruit consumption can raise plasma levels of Flibanserin by a clinically meaningful margin and amplify side effects.
What to do with Flibanserin
According to the prescribing information for Flibanserin, if grapefruit is flagged as an interaction, the safest practice is to avoid grapefruit entirely or to discuss timing with the prescriber. Flibanserin acts as a serotonin 5-HT1A receptor agonist and 5-HT2A receptor antagonist, with additional effects on dopamine and norepinephrine signalling. A small occasional serving may be tolerable; daily large servings around the time of Flibanserin dosing are not recommended at 100mg.
Frequently asked questions
Can I eat grapefruit while on Flibanserin? ▾
For some Multifunctional serotonin agonist/antagonist (HSDD) medications, grapefruit is best avoided or limited because of CYP3A4 inhibition. Whether Flibanserin specifically is affected depends on Flibanserin; the prescribing information lists this. When in doubt, ask the pharmacist or check the patient leaflet.
How much grapefruit is too much with Flibanserin? ▾
For drugs where the interaction matters, even modest daily grapefruit intake (one whole grapefruit or one large glass of juice) can shift drug levels noticeably. For Flibanserin at 100mg, individual tolerance varies; the cautious choice is to avoid grapefruit if any interaction is mentioned.
Products containing Flibanserin
More on Flibanserin
- With alcoholFlibanserin and alcohol — is it safe to drink?
- With foodShould Flibanserin be taken with food?
- Side effectsFlibanserin side effects: common, rare and warning signs
- Dosage guideFlibanserin dosage guide: how much to take and when
- OnsetHow fast does Flibanserin start working?
- DurationHow long does Flibanserin last?
The information on this website is provided for reference and educational purposes only. It does not replace consultation with a qualified healthcare professional.