Here is a blog written by a doctor who uses high dose methylB12 for autistic patients.

It explains the glutathione issue: His opinion:
http://www.generationrescue.org/dr-j...d-vitamin-b12/

Most people as they age develop LOW glutathione. So the emphasis is on keeping adequate glutathione levels for good health.

Here is a pretty good explanation from Dr. Mercola about glutathione:
http://articles.mercola.com/sites/ar...pplements.aspx

The amount of whey in a protein bar is quite low. Whey protein is a provider of amino acids just like a steak would be, only they are in a form that does not require digestion. Poor digestion of protein can come from using acid blocking drugs too much, or not eating animal sourced foods, which have the sulfur rich amino acids in them.

When whey is used by the scoop in smoothies, more is typically consumed that way.

I saw glutathione mentioned in Dr. Jay Cohen's website, in relation to reversing a PN that was caused by Levaquin in one patient. This is an anecdotal report, where the patient received IV glutathione and the PN improved. (PN from antibiotics like Levaquin is thought to be irreversible, but glutathione helped that one patient).

Here is a paper from a pain management seminar that discusses using glutathione (along with other supplements) to treat neuropathy:
https://docs.google.com/viewer?a=v&q...F891DwtcwaL3Aw

Some people don't like NAC, and it can cause itching or burning of the skin in some. Here is a good explanation of NAC and also some of the side effects reported:
http://www.webmd.com/vitamins-supple...TYL%20CYSTEINE

I think the subject of B12 with glutathione is very complicated and perhaps too biochemical to really understand for most people except biochemists. But I have never seen comments about too much glutathione!

http://www.immune-health-solutions-f...e-effects.html

To illustrate how complicated it can be here is a pathway chart of how glutathione is metabolized and created:
http://www.genome.jp/kegg-bin/show_pathway?map00480

Each box with a number in it represents an enzyme involved.
And there are several pathways involving several amino acids too, glycine, proline, taurine, cysteine, methionine, etc.

Glutathione itself is not well absorbed orally. There are new products out that make a liposomal suspension of glutathione, so it will be absorbed orally, so IV is not necessary. This type of suspension is tiny spheres of glutathione with a phosolipid membrane in nano size dimensions, and this delivers the glutathione to the liver adequately.

Using NAC only provides the cysteine for the complicated pathway in the link I showed you. You can see it is a very small contribution compared to everything else that can happen. And just because you take it, doesn't mean it gets used where YOU want it. The body's chemistry and enzymes determine that.

This is very complex...so go slowly reading and you may have to read several times to get the gist of it all.

Swallowing a sublingual works as well as oral in studies for B12. But you have to do this on an empty stomach for best results.