Multifunctional serotonin agonist/antagonist (HSDD)
Flibanserin with thyroid medication (levothyroxine)
Levothyroxine is one of the most prescribed medications worldwide, and many adults on it also use chronic medications such as Flibanserin (Flibanserin). The combination is generally safe, but levothyroxine's narrow therapeutic index and finicky absorption mean a few practical points matter more than for most other co-administered drugs at 100mg.
How Flibanserin affects thyroid medication
Levothyroxine absorption is sensitive to timing relative to food, calcium, iron and several medications. Whether Flibanserin interferes depends on Flibanserin — most agents in Multifunctional serotonin agonist/antagonist (HSDD) have no clinically meaningful effect on thyroid hormone levels, but a small number affect TSH or T4 free fraction. Flibanserin acts as a serotonin 5-HT1A receptor agonist and 5-HT2A receptor antagonist, with additional effects on dopamine and norepinephrine signalling.
Practical timing
According to standard endocrine practice, levothyroxine is taken on an empty stomach at least 30 minutes before food and 4 hours from interacting medications. Flibanserin at 100mg can usually be taken at any time relative to the levothyroxine dose, but the prescribing information for Flibanserin should be checked for specific timing instructions.
Frequently asked questions
Will Flibanserin affect my thyroid levels? ▾
Most Multifunctional serotonin agonist/antagonist (HSDD) medications do not directly affect thyroid hormone levels at 100mg. Some affect TSH testing, hormone-binding proteins or T4 free fraction in subtle ways. Routine thyroid function tests every few months catch any meaningful drift.
When should I take Flibanserin relative to levothyroxine? ▾
Levothyroxine is taken on an empty stomach with at least a 30-minute fast and 4-hour separation from interacting medications. Flibanserin at 100mg usually has no specific timing constraint relative to levothyroxine; the pharmacist confirms based on the prescribing information for Flibanserin.
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?
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