Clen isn't considered a very toxic drug. It isn't used in the body the same way that oral steroids are. Whether injecting it sub q or taking it orally, I wouldn't expect a healthy individual to have issues with their organs. You may find that the injectable is stronger mg for mg and the yohimbine HCL may intensify side effects such as anxiety. Too much clen can lead to low BP so pay attention to that. If you find that shortly after your injection, you feel light headed, weak, sleepy or have irregular heart beat, your BP may be low. Yohimbine HCL can also be taken orally, if you decide to go the oral route. It is a great addition for a fat loss stack, especially for females. It will more specifically target estrogen related fat (which both men and women can have). 

With anything new, I start my dosing low to see how I respnd. As I mentioned, you may find the injectable strong, so even if you have used oral clen, I would still back off on the dose, between .25 to .5cc ED, taken sub Q, with an insulin pin, shot directly into the fat that you want to target. Be sure to rotate your site injecting one side one day, the the other side the next. When you go back to the first side, move the injection site by about 2 inches away from the first. Basically, avoid shooting it directly in the same spot every time. As you progress, I would move on to 1cc per day directly into the fat that you want to eliminate. If you can tollerate more, I would work up to no more than 2cc per day