I take C1000mg with my pre workout stack containing: Collagen powder , gelatin powder , creatine, bcaa , pre workout -> fish oil, multi vitamin, vitamin C1000 and magnesium. Also eat a lot of broccoli which contains high amounts of vitamin C. Any excessive amount of vitamin C will be excluded via urinating so you can’t and too high amount anyway. This works wonders for my tendon injury. Also diary products and sugars are VERY bad for inflammation. Besides that any amount of testosteron above a TRT dose will heavily reduce collagen type-1 synthesis hence make your tendons weaker and definitely don’t improve them.