First, I don't know how old your husband is, but if he needs this in order to hike the way hunters hike, he's probably too unfit to do much of anything. Hunters don't do a lot of exercise. They get to a spot and then sit there and shoot the breeze all day and if they see something they try to kill it. Unless he's also doing the skinning and all that. But even then, there's so much rest time in hunting that he shouldn't need any supplement to do it. As to its effect on the drug, the drug is a very stimulating antidepressant because of its effect on norepinephrine, which is adrenaline. The C4 contains things that will increase adrenaline as well. The B6 is very high, and that has an independent risk for some people of causing a form of irreversible neuropathy. It's loaded with caffeine. It has nutrients in it that affect nitric oxide and testosterone, which if his depression comes along with anxiety can make it worse, but then, so can the drug he's on so that may not be a problem for him. It won't counteract the drug, if that's what you mean, but he doesn't need it, he can accomplish that better by practicing hiking to build up his endurance than taking this stuff. The only people who really use this stuff are bodybuilders, who will take absolutely anything to get bigger muscles and make their workouts last longer. But for hunting? Won't help. Might make him very nervous if he's prone to that.