I agree with Eric, as long as the chelator is used *safely*.
This is all quite complex. DMSA & ALA don't do exactly the same things. If you are trying to get rid of lead, DMSA is the preferred chelator; however if mercury is the problem, you'll need to use ALA to get it out of your brain.
Beware that incorrect use of ALA will often result in an *increase* of mercury in the brain! Cutler explains briefly in this discussion of a double blind study with mice. http://onibasu.com/archives/am/74605.html