What are the active ingredients in Active B12 with L-5-MTHF lozenge derived from? Ceylon Keeslar October 31, 2019 17:22 Updated Follow Vitamin B12 as adenosylcobalamin is from fermentation. Vitamin B12 as methylcobalamin and folate are synthetic. Related articles Does Active B12 with L-5MTHF lozenge contain gluten, soy, or grains? Comments 0 comments Article is closed for comments.