Short answer: Usually, yes. Metformin extended-release labels say the inactive parts of the tablet may pass in the stool as a soft mass that looks like the tablet, and the Glumetza and generic ER leaflets say this is normal and does not change how the medicine works. The Janumet XR label adds that seeing tablets in the stool repeatedly should be reported to a clinician.
Extended-release tablets are built to release metformin slowly over the day so they can be taken once daily, usually with the evening meal (Glumetza and generic ER labels, section 2.1). The medicine leaves the tablet as it moves through the gut, and the parts that do not dissolve can come out looking like a whole tablet. See extended-release.
The generic metformin ER label (section 17) says the inactive ingredients may occasionally be eliminated in the feces as a soft mass that may resemble the original tablet. Even the plain metformin leaflet notes you may sometimes pass a soft mass that looks like the tablet. The generic ER label starts at 500 mg once daily with the evening meal and goes up to 2,000 mg once daily (section 2.1).
| Product | What the label says |
|---|---|
| Metformin ER (generic) | May pass a soft mass that looks like the tablet; not harmful and will not affect how the medicine works (Patient Information) |
| Glumetza | May pass a soft mass that looks like the tablet; this is normal and will not affect how Glumetza works (Patient Information) |
| Metformin immediate-release | May sometimes pass a soft mass in the stool that looks like the tablet (Patient Information) |
| Janumet XR (sitagliptin and metformin ER) | Incompletely dissolved tablets may be eliminated in the feces; repeated sightings should be reported, and blood sugar control checked (section 17) |
The Janumet XR wording is the most cautious: it calls them incompletely dissolved tablets and asks clinicians to check whether blood sugar is still controlled when a person sees them often.
Every extended-release label says to swallow the tablet whole and never crush, cut or chew it, which keeps the slow release intact. Janumet XR adds that people taking two tablets should take them together.
An occasional soft tablet shape with steady blood sugar matches what the labels describe. It is worth asking the prescriber or pharmacist if it happens often, if the shape looks hard and unchanged, if diarrhea is moving things through quickly, or if glucose or A1C readings have risen. They may check whether the medicine is being absorbed or suggest another form. Dose Track can log each dose with a note on what you saw, next to your glucose readings, which makes the pattern easy to show.
Read more on Dose Track: Extended-release · Metformin side effects · Metformin dosing schedule · Januvia vs Janumet