In the information from heartfixer and yasko etc.. mention is often made of those with COMT + status and their probable inability to handle methyl donors. In such cases they often advise that the patient would have difficulty tolerating methyl B-12 and would do better on hydroxy B-12. But, I have not found any mention of difficulty tolerating methylfolate. Wouldn't it make sense that if (in this theory) you can't tolerate methyl donors, and then can't tolerate methyl b-12, a patient would also have difficulty tolerating methylfolate, and therefore folinic acid may be a better option for that patient ? I admit, I don't have a thorough understanding of the methyl cycle or the interplay of all the various genetic SNP expressions, but this was just an idea that occurred to me, as I seem to have a very difficult, if not impossible time tolerating either MB12 or methylfolate, but hydroxy b12 seems ok. I am undecided on the the folinic acid, as I have never taken it without also being on methylfolate. I wondered if anyone else had a similar experience ?