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Can metformin raise bg?

Lizzypier

Lizzypier

Active Member
Messages
26
Type of diabetes
Type 2
Treatment type
Diet only
Quick question 3 weeks into new regime
New to metformin. One 500mg at breakfast. Low carb less than 40g per day.
According to cgm
Waking 8.9
Before breakfast 8.6 (12g carbs)
2 hours later 8.8
5 hours later 6.3
And it remains between 5.9 and 7.4 until t next morning.

So the metformin meal has the biggest spike daily.

Is this normal when starting on meds?
 
Lizzypier said:
Quick question 3 weeks into new regime
New to metformin. One 500mg at breakfast. Low carb less than 40g per day.
According to cgm
Waking 8.9
Before breakfast 8.6 (12g carbs)
2 hours later 8.8
5 hours later 6.3
And it remains between 5.9 and 7.4 until t next morning.

So the metformin meal has the biggest spike daily.

Is this normal when starting on meds?
Click to expand...
The odds are you're not seeing a rise due to the metformin, but it's Dawn Phenomenon at work. It's the liver releasing more glucose than you need, to help you start the day. Just happens to occur in the morning, when you take the metformin as well. (And after a while, metformin should keep you from spiking so much from a liver dump). If you ate the exact same meal at dinner, you wouldn't see the same rise, and if you had the same meal in the evening with metformin, it likely wouldn't happen either.

Can't be 100% certain of course, but... I see something similar happening on the Libre I'm wearing for a bit. I'm not on metformin, but I do low carb, and if I have breakfast, I see a quick rise: dawn phenomenon at work while the 7,5 grams of carbs I have in the morning is at work as well. I rise up into the nines and then it drops like a stone soon after. Unless I'm stressed about something, then my bloods rise again. All in all though... There's more at work than medication and food... Dawn Phenomenon is a thing, so are stress spikes, or due to a cold, or.... Give it a little time, see what happens eh.
Good luck,
Jo
 
@Lizzypier Metformin doesn't directly reduce BG and is a long lasting medication which takes time to build up within your body. So it's unlikely you will see any effect from Metformin for a week or so.

In any case, the effect of Metformin is on the liver in reducing the amount of glucose that the liver produces when you wake or exercise - it has no effect on the digestion of your meal (the sugars and starches) into glucose, so even when working it won't show up on your mealtime glucose rises.
 
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