First of all, have you had all your amalgam fillings replaced? Before starting on ALA, it is a good idea to take DMSA alone(every 4 hours 3 days on 4 days off) for a few months. If you don't plan to use DMSA, then at least wait a few months after amalgam removal before starting ALA. A good starting dosage for ALA is 25 mg every 3 hours for days, then take 4 days off. After doing this for 2 weeks with minimal side effects, you could raise the dsage to 50 mg,

If someone who is mercury toxic starts with a 300mg ALA dose, they will probably feel very sick.