In Amy Yasko's protocol, she recommends starting with some TMG, and then after the B12 and folate have been built up some, to add DMG, which will inhibit the BHMT reaction by product inhibition, and that will push more of the homocysteine through the methionine synthase reaction. It's important to get this enzyme going, because it is linked to the folate metabolism, which is needed to make new DNA and RNA, and also because it regulates the entire sulfur metabolism. TMG will promote production of SAMe, but it can shunt flow away from the methionine synthase enzyme, which is partially blocked in ME/CFS. However, note that TMG stimulates the alternative BHMT pathway from homocysteine to methionine in the liver and kidneys. Yes, if you take betaine HCl, you will also have the benefit of TMG. Betaine HCl has a hydrochloric acid molecule bound to it.
