Why are animals tested on when there are perfectly good human tissues?
This is because the body of a human and any other animal is a lot more complex than a mere tissue. The physiology of the whole body is extremely complex. Many things can go wrong when a drug is introduced into an organism. Of course only drugs which are rendered as “safe” when tested on a tissue will go on to further experiments on animals, but sometimes, the presence of other natural body components which had not been taken into account might somehow make the drug potentially dangerous. If the drug was to be tested straight on humans, you can see that companies would have huge lawsuits, and lots of lives would be lost. Testing animals first prevents this, and it’s the reason it is done.
