More specifically, the methylcobalamin form of B12 is recommended, as it has been shown to be the most effective. Taking B12 gives you a huge boost of energy while training, and more importantly, greatly helps your recovery.
I aftually just did alot of research and it turns out tren can cause tren cough from just having tren in your system, you dont even need to hit a vein. Kinda like having a non drowsy non shitty feeling bronchitis. Coughing from hitting a vein with ANY gear is actually totaly normal. When you hit a vein with gear, i read it creates a thickening of blood in your veins and creates fluid to be pulsed to the lungs. This causes respiratory distress, heavy chest feeling, wheezing, heavy breathing, coughing, dry throat, feelings of burning in the lungs, and more. I guess i answered my own question lol. So tren cough is definitely real, it causes a minor fluid backup in the lungs for the length of your cycle whether you hit a vein or not, and any gear injected straight into a vein will cause severe respiratory distress and possible failure (in large amounts like 5 to 10 ml straight iv) and makes it hard to breath. Upon accidental injection of minor amounts of gear into your vein, try to sit down, relax, drink water, try to take slow medium deep breaths, cough, and let it pass.