Metanx consists of three ingredients: folic acid, vitamin B6 and vitamin B12. It is not a medication, but a "medical food," so it is not available as brand name or generic drug. The vitamins in Metanx may be taken individually or in combination products such as Folax, states eMedTV.
Metanx helps people with diabetic neuropathy, a complication of diabetes that causes loss of sensation and pain, notes Monthly Prescribing Reference. Doctors also prescribe it to treat hyperhomocysteinemia, states Drugs.com. Side effects include sleepiness, upset stomach, abdominal pain and headache. Metanx is not recommended for children or people who are taking certain medicines or those with pernicious anemia, Monthly Prescribing Reference reports.