Qsymia
A phentermine-topiramate combination capsule — the strongest pre-GLP-1 oral, averaging around 10% loss at top dose.
Qsymia combines low-dose phentermine with extended-release topiramate, an anticonvulsant with appetite-suppressing side effects. The pairing was the most effective oral regimen of its era: top-dose trials averaged near 10% body-weight loss, approaching injectable territory.
Its constraints are pharmacologic: controlled-substance scheduling via phentermine, cognitive side effects ("word-finding" complaints) and tingling from topiramate, and strict pregnancy prevention requirements because topiramate causes birth defects. Qsymia persists as the serious oral alternative for patients who decline injections and tolerate its profile — though the arrival of high-dose oral semaglutide has crowded that lane considerably.
This glossary entry is general information, not medical advice, and is written to be consistent with FDA prescribing information and primary trial publications as of its last review. Always consult a licensed healthcare provider for personal medical decisions.
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