I felt very sick after using ALA alone for a few weeks. I can tolerate ALA much better when it is taken with DMSA. Can you buy DMSA from abroad, or is it illegal to do so? DMSA is also called Chemet, Succimer, or Captomer(or perhaps other names as well?) Try asking for it under those names. In the US ALA is available in doses of from 25 mg to 600 mg, although just a few places have the 25 mg. 50 mg is sold in the US by a few different brands. Source Naturals, Country Life, Vitamin Shoppe,
Natrol, and perhaps others as well?

25 mg a dose(200 mg a day) ALA is a good starting dosage. ALA is probably stable enough that you could dissolve a 200 mg from a capsule in 8 ounces of water, then drink one ounce each 3 hours(keep the liquid in the fridge in a sealed container, and shake it well before each use). Don't do this with DMSA as it is very unstable when mixed with water. It is not a good idea to keep dissolved DMDA for more than 6 hours or so, even refrigerated in a sealed container filled to the top. I only keep the dissolved DMSA for around 3 hours(I dissolve the contents of a 100 mg capsule to get two 50 mg doses).