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Qsymia

How to take Qsymia

One capsule, once a day, in the morning

Last reviewed: September 2026

Qsymia (phentermine and topiramate extended-release) is one capsule taken by mouth once daily in the morning, with or without food. The FDA label specifically says to avoid taking it in the evening because of the possibility of insomnia. Before you start, the label asks for blood tests and — for anyone who can become pregnant — a negative pregnancy test.

Taking Qsymia

The label has one timing rule and it is about the morning, not about meals.

1
Take it in the morning

The label says to take Qsymia orally once daily in the morning, and to avoid taking it in the evening because of the possibility of insomnia. Pick a morning anchor that is easy to keep.

2
With or without food

The label sets no meal requirement. The capsule can be taken with breakfast or on an empty stomach — whichever is easiest to keep up.

3
Start on the diet and exercise programme

The Medication Guide says your healthcare provider should start you on a diet and exercise programme when you start Qsymia, and that you stay on that programme while you are taking it.

4
Keep to the dose you were given

The Medication Guide says not to change your dose without talking to your healthcare provider. The step up from 3.75 mg/23 mg to 7.5 mg/46 mg, and beyond, follows the schedule in the label.

5
Drink plenty of fluids

The Medication Guide says to drink plenty of fluids while taking Qsymia to help decrease the chance of kidney stones, and to call your provider if you get severe side or back pain, or blood in your urine.

Why the rule exists

Qsymia is an extended-release capsule that pairs phentermine with topiramate. The morning timing in the label exists because of insomnia risk. Topiramate is also why the label attaches monitoring to the drug: a negative pregnancy test before starting and monthly during therapy for anyone who can become pregnant, and a blood chemistry profile including bicarbonate, creatinine and potassium before starting and periodically afterwards.

Pill storage

Where to keep it

Room temperature, 68–77°F (20–25°C)

Container

Keep it tightly closed

Avoid

Moisture — keep Qsymia dry

If you miss a pill
1
You miss a morning dose
Wait until the next morning and take your usual dose then.
2
Never
Double your dose to make up for a missed one.
3
Thinking of stopping
The 15 mg/92 mg dose is tapered to every other day for at least a week first — talk to your prescriber.

Common questions

Written and maintained by one person · Built with agentic AI tools · Every number checked against the cited trial · Not medical advice

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Keep reading

Full Phentermine / Topiramate ER overview →Dosage guide →Storage guide →Drug interactions →

Next step most people take

See the dosage guideWhat the label says about each doseIf you miss a doseThe label instruction, step by step

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Medical disclaimer: This website is for informational purposes only and does not constitute medical advice. Always consult a qualified healthcare provider before starting, stopping, or changing any treatment. Prices shown are United States self-pay or list prices and vary by insurance and country.