Kathy asked
Can you tell me the best time to take metformin?
At a glance
- Metformin should always be taken with food. Immediate-release products should be taken in divided doses with meals while extended-release products should be taken with the evening meal.
Answer
When to take metformin depends on which product you are taking as there are several different ones. They are:
- Immediate-release tablets
- Extended-release tablets (which includes Glucophage XR, Glumetza and Fortamet)
- Solution
In the next sections, I discuss when it is recommended to take metformin based on which product you are taking.
Immediate-Release
Immediate-release metformin tablets should be taken with meals.
Per the prescribing information for metformin:[1]
GLUCOPHAGE [immediate-release metformin] should be given in divided doses with meals.
Extended-Release
There are three different extended-release metformin products:
- Glucophage XR
- Glumetza
- Fortamet
All 3 products utilize different mechanisms that release metformin slowly over time, but they are all recommended to be taken the same way, once-daily with the evening meal.
From the prescribing information for Glumetza:[2]
GLUMETZA therapy should generally be initiated with 1000 mg daily which should be taken with food preferably in the evening.
Similarly, from the prescribing information for Fortamet:[3]
FORTAMET® should be taken with a full glass of water once daily with the evening meal.
Lastly, from the prescribing information for Glucophage XR:[4]
GLUCOPHAGE XR should generally be given once daily with the evening meal.
Solution
In addition to the solid dosage forms for metformin, it is also available as a solution (Riomet). Each dose should be given with meals:[5]
RIOMET should be given in divided doses with meals.
Final Words
The dosing recommendations for metformin is pretty clear cut, take with food.
If you are taking more than one dose per day (which is typical with the immediate-release tablets and solution), try to separate them evenly. For example, if you take metformin twice a day, breakfast and dinner would be the best options.