I removed my last filling two weeks ago.
I intended to follow the Cutler protocol and I started my first round with 6 mg DMSA. However even with this low dose my stomach cannot tolerate it and I get gastritis.

I'm not sure how to proceed. I suppose that both DMPS an ALA will give the same type of problem since they also contain two sulphur atoms.

I could of course try chlorella and cilantro but it is not according to the protocol.

Any suggestions how I should proceed?

What happens when you take DMSA? Do you get gas, bloating, or diarrhea? How bad are the side effects? Everyone who is mercury toxic gets at least some adverse reaction to DMSA and ALA.

Before trying DMSA again, I suggest that you do a one month parasite cleanse if you haven't done one recently. You should also go on a low carb diet and eliminate sugar and alcohol completely, as these feed candida. If your body is toxic from parasites and/or candida overgrowth, then you will have a hard time tolerating the chelation side effects.

Are you sensitive to perfumes, chemicals, and sulphites? If so, then perhaps you may be deficient in molybdenum.

What JK98 has said above I could only confirm by my experience with bad candida. I was not tolerating chelation and my gut was terrible. Pain, bloating, everytime I tried to chelate. I would suggest the same - stop the chelation and treat possible candida with a low carb, no sugar, no yeast, no wheat/gluten diet and see if things improve for you and try the DMSA again later as you feel stronger.

If you find the DMSA continues causing these problems, regardless of what efforts you've make, and in spite of reducing possible candida levels, it may not be for you.

You do not have to take DMSA. It is optional, but it can help your body remove mercury and often helps with side effects. Alpha lipoic acid is apparently essential according to cutler. So you could wait out this time (first 3 months) and not chelate at all and simply start ALA on its own once the 3 months are over and use it as a single chelator.

Chlorella is high in sulfur by the way. Cilantro is a brain chelator and there is not a protocol in place to make sure of its safety in chelating mercury.

I'd personally try the diet if you haven't already and go from there and then give DMSA another go in case this is candida related. I could not tolerate DMSA chelation until I dealt with my gut candida. It really had gotten that bad, but I had not noticed it. I thought I was already on a pretty good diet, but it was not enough. There has to be a complete removal of sugar/gluten/yeast from the diet and a reduction in high carbohydrates even in healthy/natural foods if the candida is bad enough. You may get away with a few high carb natural foods, but that will depend on how bad the yeast problem is and how your body responds.

Thank you for your answers.
I get a burning sensation in the stomach immediately after taking DMSA and later pain. Since the reaction is so immediate, I guess it is caused when the DMSA is absorbed in the stomach. Same thing if I try to eat raw onion.

When I take the DMSA, I open the gelatin capsules in order to control the dose. Will the capsule somehow affect the absorption?
For example where it is absorbed.

I have been on a low carb diet for a long time (9 months) but perhaps I can try to impove it further.
I will try molbdenium to see if it helps.

Are you taking the DMSA with plenty of water? As long as you are opening the capsule, you could try emptying the capsule into an 8 ounce cup of water and stirring it well then drinking it soon after.

Perhaps you might be having a reaction to whatever else is in the capsule(filler) besides DMSA? The lower the dosage size of the capsule the greater amount of filler it will tend to have.
DMSA should also be taken on an empty stomach, otherwise absorption is decreased.