Hi Glancia, Andy has always stated ALA must be taken every 3-4 hours around the clock, just like DMSA (preferably every 3 hours). It's in his book, on everything bit of info I have read.. DMPS however does not have to be taken every 3-4 hours, but instead about every 6-8 hours. But if you use it with the ALA, that changes things apparently. Here is a link that outlines Andy's protocol.
http://home.earthlink.net/~moriam/Andy_dose_sched.html

That link explains it. The only thing I am wondering is, I cannot see why DMPS has to be taken on every ALA dose. I wonder if someone can take it like this -
e.g. DMPS and ALA at 4 pm, then ALA alone at 7 pm, then DMPS and ALA together at 10 pm, then ALA alone at 1 am, then DMPS and ALA together at 4 am etc etc. That way you are taking them both as they should be taken, but not unnecessarily wasting the DMPS in the process. Not sure why on that link it says you must dose DMPS the same as ALA if taken together. It does not make sense, as DMPS will still be remaining in the blood after 6-8 hours, so I dont believe it needs to be taken on every ALA dose.

That's just my opinion though.