Is there actually any facts on to why people are against animal testing? Almost everywhere I go, I see opinions like " Animal testing is cruel and makes animals suffer" but is there actual facts on that? The only actual fact I've seen is that ten percent of the animals tested are not given pain killers. P. S- I'm kind of in the middle of going against it and supporting it so please don't scold me for being a messed up person for thinking I am supporting it. Well, I have your answer. I am against animal testing on both moral and scientific grounds. Morally, animal testing is often extremely cruel and completely unnecessary. For example, I once saw any undercover footage from a laboratory in which dogs were being force-fed weedkiller. Allegedly, this was to see how toxic said weedkiller was. However, it had already been tested on humans, and the dogs were being given 50 times what had been established as a dangerous dose for humans – what possible reason could there have been for this? It is nothing short of torture, just like pouring shampoo into an animal's eyes just to see what happens, or infecting it with horrific diseases like cancer just to see if a potential cure works. I find these sorts of things utterly repugnant. Scientifically, testing products meant for humans on animals is unreliable and potentially dangerous. Animals react differently to humans to many substances, rendering many tests pointless. For example, a contraceptive called Tamoxifen was once developed which was tested on rats. It worked as intended, and was given to humans. However, it had the opposite effect on women, actually increasing their fertility. There are many other examples, any of which had much more harmful consequences. You may remember Thalidomide, a drug given to pregnant women to prevent morning sickness. It had been tested on animals and declared safe for humans, but it caused severe deformities in many of the babies born after their mothers had taken it. A couple of years ago a drug called TGN1412 was tested on any human volunteers, and very nearly killed them – they were on life support for any time, and were left with permanent health problems. Prior to being given to these people, this drug had already been tested on monkeys at a dose 500 times stronger than that which was given to the humans, without causing the monkeys any ill effects. Aspirin causes birth defects in cats. Penicillin kills guinea pigs. 6-azauridine, a cancer drug which can be used in humans for long periods, will kill dogs in a few days in even small doses. The list goes on. My personal view is that products meant for humans should be tested on humans. It's the only way to know if they will work as intended, and we have the choice of whether or not to volunteer for testing – animals are given no choice, they are simply used and discarded like objects. They have as much right to live as we do, and the right to live that life free of pain and misery. As noted philosopher Jeremy Bentham put it, the central question is not "Can they reason?" nor "Can they talk?", but "Can they suffer?" And must have they can. Our greater intelligence gives us a responsibility to protect other species, not the right to use and abuse them in any way we see fit – that should be abhorrent to any sentient, compassionate being.