HI Stuart, strange symptoms are typical of mercury. I used to get a feeling of mouth constriction. My mouth felt too small and my cheeks felt they were being pulled inwards. This was with or without chelation.

I have heard of chelation doing similar though, literally causing a pulling sensation. As though it's somehow pulling mercury out of those areas. Someone described the sense at the back of their head (base near the neck) as though something was pulling mercury out of that area. They would literally feel it happen.

6.5 mg of DMSA every 4 hours is the right dose to start and good to test yourself on. If you do ok on this dose and don't notice much, later you'd be able to increase. But I would not increase until you have done a few rounds first. Symptoms can catch up to a person.