I hope that you get this reply. I had (yes had) both type 2 diabetes and tinnitus. I'm not sure if the metformin caused the tinnitus but I didn't have it until about a month after taking the drug. I know how terrible that ringing can be and I read up on everything I could find about it. The more I read the more discouraged I got until I found a few facts about tinnitus and metformin. Metformin can drop your B12 levels and a symptom of dropping B12 can be tinnitus. Zinc, CoQ10 and ginko biloba are also things that I learned that could treat the problem. I'm not a doctor so I can't say for sure how much of these supplements is too much on a daily basis but what I did was take 5000mg of B12 (spread out through the day, not all at once) and doubled the suggested daily dosage of the other 3 supplements. Last and most important I believe is that I prayed (a lot) and told myself that I was healed and resisted the thoughts that I would have this problem for the rest of my life. In about 3 days I started to notice that the ringing was starting to be more sporadic instead of constant. In five days it was gone and has been ever since. I've cut down on the intake of those supplements and have thanked God every day since. I hope and pray that you and anyone else that suffers from tinnitus reads this and that this works for them as well as it did for me. Don't give up if it doesn't go away as fast as mine did, keep trying this or searching for something else that will work for you. There is a way to cure your problem, believe it.
As for the diabetes I suggest you try the system that I did. it's a bit extreme but it's free and it helped me. I no longer take meds for blood sugar and I've lost significant weight. The system is called Reboot with Joe......google it and stick with a plan....I pray that this is an answer for your blood sugar issues as well. (I forgot to mention above that I was checking my blood sugar during the diet plan and stopped taking metformin once I noticed my sugar levels were under control. I started the supplements right around when I stopped the metformin. This also may have been a factor in the tinnitus going away but i'm not sure since I was doing everything pretty much at the same time. Do not cause yourself any damage by dropping your meds....this is just what worked for me.....if what I did is a healthy choice for you I hope that it works for you too.)
