IV would be the preferred way of getting glutathione into the system... Oral routes are tricky b/c the stomach acids are going to break the tri=peptide apart rendering it useless. I have used the Readisorb product with success, but I found out the hard way when I used too much that it was releasing toxins out of the liver into the intestinal tract via hepatobilary tree and those toxins were feeding my infection.
So I backed off and went back to a 1/8 to 1/4 teaspoon and have gradually worked up.