I understand that Merk has the patent on the best stuff. I am understanding (?) that there are some brands out there that say they have 5 methyl THF that do not have this particular Merk form.. or do all products that claim to contain 5 methyl THF have the Merk product? I am using Thorne's Bs and 5 methyl THF. I called them to ask if this is metafolin from Merk and they would not tell me. They said I had to be a practioner for them to release that info, but they would tell me it was from Merk. I really don't appreciate having this info withheld from me since I am the one purchsing the stuff and basically my life depends on it being the right stuff, but there you go. Since I cant get a straight answer from Thorne, I am hoping someone can help shed some light on this for me. I like using this product because it is already powdered in capsules and has no fillers. Thank you!