Synthyroid and Metformin

[care610]

I was just prescribed Metformin for PCOS. I have been on Synthyroid since may but now I was recently prescribe Metformin. I forgot to ask if it safe to take Metformin with Synthyroid at the same time. Does anyone if it would be ok?

[care610]

Thanks I will be working myself up to 500 mg of Metformin TID. I will continue to take my Synthyroid at 5 AM then first dose at 9am When I work myself up.

[Barb135]

Synthroid should be taken on an empty stomach with a full glass of water, then eat or drink nothing else for at least 30-60 minutes.  

It's also recommended that you not take most vitamin/mineral supplements within 4 hours of taking synthroid (levothyroxine).  

I did a quick search for drug interaction and came up with the possibility that synthroid may inhibit the absorption of metformin, thereby causing hyperglycemia or glucose intolerance.  You might want to talk with your doctor about separating the 2 medications for a few hours.  

I don't know the dosing instructions for the metformin, but maybe if you take your synthroid at, say 7:00 am, you could take the metformin around noon....... Talk to your doctor to be sure.