Welcome to NeuroTalk. Metanx has been discussed quite a bit on
our forums.

This most recently:
http://neurotalk.psychcentral.com/sh...ghlight=metanx

Brand name Metanx has activated vitamins helpful for neuropathy and for people with MTHFR genetic failures, who cannot activate vitamins from supplements.

If you search Metanx you will get all the threads that discuss it.
example:
http://neurotalk.psychcentral.com/se...chquery=metanx
41 threads on PN alone.

Be advised that generic versions of this product are problematic.
You can buy the ingredients separately OTC for less than the RX costs if your insurance doesn't cover it.

I would keep the folate low if you do it yourself, because folate has not shown major benefits for PN and has been under scrutiny for possibly enabling colon cancer in some people.
The last post on that first link I gave you has a doctor's opinion on the folate research that is going on right now. Metanx is pretty high in folate, and if you take 2 a day, you will be in the dose range that is being investigated.

Methylcobalamin oral is quite inexpensive and can be purchased for pennies a day.