THORNE RESEARCH Methyl-Guard Plus (5-MTHF) 90 Capsules

Supports heart, blood vessel, brain, and bone health by enhancing healthy methylation.
Methyl-Guard Plus provides 5-MTHF (active folate) and the active, tissue-ready forms of vitamins B2, B6, and B12 to support healthy methylation for cardiovascular, cognitive, and bone health.


Methylation is key to keeping homocysteine levels in check, as well as for facilitating multiple biochemical processes involving neurotransmitter synthesis, detoxification, cardiovascular health, eye health, muscle health, bone health, and redox balance. Maintaining a desirable level of homocysteine in the blood has joined healthy cholesterol and triglyceride levels as leading biomarkers for the maintenance of good cardiovascular health. Preventing an undesirable homocysteine level is also associated with the maintenance of bone, female reproductive, cognitive, and neurological health.* Methyl-Guard Plus supports methylation and promotes healthy homocysteine levels with betaine (trimethylglycine), 5-MTHF (the active form of folate), riboflavin 5'-phosphate (the active form of vitamin B2), pyridoxal 5'-phosphate (the active form of vitamin B6), and methylcobalamin (an active form of vitamin B12).


Methylation – the addition of a methyl group (one carbon atom attached to three hydrogen atoms) to another molecule – is an essential and vital biochemical process that is involved in multiple biochemical pathways involving neurotransmitter synthesis, detoxification, cardiovascular health, eye health, muscle health, bone health, and redox balance. A number of specific nutrients are necessary for methylation processes to occur normally.* Maintaining a normal homocysteine level in the blood is important for good cognitive health.* A deficiency in the cofactors that metabolize homocysteine is commonly observed in the elderly, which results in increasing homocysteine levels with advancing age. These elevated levels of homocysteine associated with aging, as well as low levels of folic acid and vitamins B6 and B12, can result in the decreased methylation of numerous substances, including DNA and proteins, which can diminish the integrity of vascular structures and neurons. Therefore, providing nutritional cofactors for homocysteine metabolism provides support for a healthy brain.


A number of biochemical imbalances that can raise homocysteine levels can be addressed by supplementing with the appropriate nutrient cofactors. These include folic acid (as L-5-methyltetrahydrofolate), vitamin B12 (as methylcobalamin), and betaine (trimethylglycine), which promote the recycling of homocysteine to the amino acid methionine. In addition, the breakdown of homocysteine into beneficial amino acids cysteine and taurine can be facilitated by pyridoxal 5'-phosphate (the active form of vitamin B6). Studies have shown these nutrients help maintain normal homocysteine levels in the blood.