The adverse effects of intravenous glutathione speculatively arise from the direct delivery of huge amounts of the molecule in the blood circulation
(PubMed) Han B, Li X, Yu T
While corticosteroid injections can reduce pain in some cases, repeated use may not always be ideal for tendon health
If you are taking glutathione to brighten your skin but spending hours in the sun without protection, you are essentially pulling your body in two different directions
There is also some research showing that citric acid with regular use (think three months and 20% concentration) can help sun-damaged skin, increase skin thickness and some nice hydrating things called glycosaminoglycans in the skin
Add a well-formulated glutathione serum to your routine, pair it with Vitamin C and SPF, and give your skin the patience it deserves, and the results will show up.