I don't think IV glutathione is available without a prescription. But the precursors are supplements that can be purchased online or in a health food store. I think N-Acetyl-Cystein (NAC) is one of them, Alpha-Lipoic Acid may be another (going from memory here...).
Also there are herbs that help to support the liver, kidneys and bowels that could aid with toxin removal.
Milk Thistle is excellent for the liver. Dandelion root is good for both liver and kidneys. Fresh squeezed lemon juice with a little olive oil (I don't remember the exact recipe -- some use apple cider vinegar instead) is good for flushing toxins out through the gallbladder (via bile) -- if you don't have gallbladder disease/gallstones.
Fiber supplements, such as flaxseed meal, pectin, psyllium husk, etc., can help bind toxins to help eliminate them from the body. Charcoal tablets absorb toxins as well (sometimes given to people who overdose on chemicals or medications). There are also edible clay supplements that do similar things to the charcoal tablets.
Coffee enemas also are good for detox.
Mucilagenous herbs (such as Slippery Elm, Marshmallow Root, Licorice Root, etc.) help protect the mucosal barrier in the gastrointestinal tract, thus reducing leaky gut issues and preventing autointoxication (re-absorption of toxins).
Digestive enzymes can improve digestion and break down toxin accumulations in the gut, making the digestive system more efficient and effective as a means of toxin elimination. Probiotics (Acidophilus, S. Boulardii, soil-based organisms) also help clean up the gut.
Drinking plenty of non-sugary liquids is very, very important as well - especially if using fiber supplements, charcoal, and/or clay supplements to pull toxins out through the bowels.
Dairy and gluten grains (wheat/rye/barley) are known to hang around a long time in the gut (approx. 6 weeks) and longer in the brain (up to a year). In those who have difficulty processing the proteins from dairy and gluten grains, these proteins can block detoxification and cause a lot of other problems. Also, gluten and dairy proteins are known to promote inflammation in the body. Inflammation increases the toxic burden that the body's immune system has to deal with. So some find they need to avoid dairy and gluten grains to achieve the healing they are seeking.
I hope this helps - good luck,
Chronic Lyme Disease, Gluten & Sulfite Sensitivity, Many Food/Inhalant/Medication/Chemical Allergies & Intolerances, Asthma, Gut issues (dysmotility, non-specific inflammation), UCTD ("Secondary Lupus-Like Syndrome"), Osteoporosis, chronic Lymphopenia, intermittant pancytopenia, chronic malabsorption/malnutrition, etc.; G-Tube; Currently TPN-dependent.
Meds: Pulmicort, IV Ceftazidime, Heparin (to flush PICC line), Claritin, Domperidone, Colloidal Silver (used topically), probiotics, homeopathy.