glp 1 drugs metformin does have Metformin: Is it a drug for all reasons and diseases? Metformin vs. GLP-1 Receptor Agonists:

Most people feel results for up to a week or more

Other Glutathione-Sparing Compounds Several nutrients help maintain glutathione levels by reducing its consumption or supporting its recycling: Vitamin C (ascorbic acid): Spares glutathione by scavenging reactive oxygen species directly, reducing the demand for glutathione as an antioxidant

Mol Interv 7:313324 Woodward W, Fischer JH, Johnson JE (2016) Evolution of oxygenic photosynthesis

So the "you must never combine them" rule overstates a real but small concern

The role of the injection is typically to provide sufficient pain relief to allow a return to everyday activities and to make progress in physical therapy