FranzFan, I agree with Valentijn - it seems that Rich advocated starting out with hydroxocobalamin first, and only switching to methyl after a few months if it didn't seem to work. To check out some good summaries of what Rich's protocol is, and learn other methylation information, see the link that is indicated in my signature line below (and make sure to read the post at the very end of the thread - it's got more detail than the first post) --> You should be taking the multi-vitamin - your body needs all the other nutrients in order to be able to utilize the B12 and folate you are taking. Most say to start with the multi and have that going for a little while before starting the methylation-specific supps. You don't have to take Yasko's multi particularly - you can approximate it by looking at the ingredients list - and not everything in it is totally necessary - but you should be taking the larger array of the B vitamins, the other vitamins, and the minerals at the very least. You can do the 23andme genetic testing from the UK. They ship internationally. The basic price is still $99 (which would be 60 or so pounds). It's worth it, in my opinion, and you find out so much more than just your methylation mutations.