Glyco is an antisecretory so it's purpose is to prevent your body from secreting any fluids, including saliva, mucus, eye fluid and of course, sweat. I stopped using it because of these side effects. I guess they're not really side effects as the glyco is doing what it is supposed to do. But I was getting massive headaches and my guess is that the fluid that surrounds the brain was being effected by the glyco in the same way as other fluids in the body so I felt like using glyco longterm will have negative and possibly permanent effect on the body/brain. Luckily, iontophoresis worked for me so I had another option. I would not use glyco long term if you have another option. I never found a way around the effects of glyco other than always carrying water on me so my throat wouldnt get too dry and even putting some drops in my eyes when they dry out.
