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 What is the reasoning for each ingredient in Active B12 with L-5MTHF lozenge? What are the ingredients in Optimal Prenatal capsule derived from? Who is Optimal GI capsules intended for? What is Adeno B12 derived from? Comments 0 comments Article is closed for comments.