There is no advantage to IV'ing sub. I did this for five years. It gives you a fuzzy feeling for like 30 seconds, and you feel like you have to dose more frequently. 4 to 5 times a day over 5 years, figure that number of injections. I have no veins left. Last time I had blood drawn I had to do it myself because the doctor couldn't. I can even hit the tiniest little spider vein in my shin. I've also drawn blood about 10,000 times from people and animals.
Anyways you should not shoot tablets. The strips you can, but it also has naloxone which causes peripheral edema in some. Over time this causes pigment to occur on your calves and ankles. Should you miss a vein you get a painful, fibrous reaction as well as scarring and pigment. I can't go to the beach.
Look, if you must shoot, shoot H, and take sublingual subs in between (yes H can kill you and the subs probably wont). Oh and if your dose is too concentrated in your diluent you can wreck a vein in 1 or two injections. I would shoot about .75mg in .5 to 1mL of saline. But still, don't do it.
Yes it fucks up your veins and when I'm old and dying of cancer this will be a problem. I still have a left AC vein and vein in my right forearm and won't ever touch those. I used to bodybuild and looked like one of those veinous freaks, not anymore.