Maybe it's just me, but I don't understand this point. I'm not sure a comparison can be drawn between the inside of veins and arteries and that of epidermal wounds. There are so many substances that run through various people's blood vessels, from illicit drugs like heroin and cocaine, to a diabetic's insulin, to countless antibiotics and other medications, to chemotherapy medications for those with cancer. I think the lining of blood vessels in much tougher than most realize. Even if SN damages the lining of blood vessels, it is certainly not instantaneous. And after all, the entire objective of taking the SN in the first place is to CTB. I'm pretty certain that an intravenous injection of enough SN into a blood vessel is going to result in death much more quickly than taking it orally. That's just my two cents.