There's really no reason to NOT start the metformin. In your case, you are insulin resistant (most likely....goes along with pcos). And the diet doesn't necessarily cure this issue. I am now at a very healthy weight, my triglycerides are silly low, my a1c is 5.0....but my fasting glucose is always around 100 and my insulin levels are high. Recent research has shown that high insulin levels, and therefore insulin resistance is just as harmful to your body in the long run as high glucose levels....and left untreated, your pancreas eventually says enough already and stops producing insulin altogether. Most do fine with metformin while on hcg. You mentioned your a1c was high....all the more reason to start the metformin. Just watch your glucose levels and report any dizziness or signs of low glucose to your doctor.