Yes. When we create a new product we need to test it to make sure it's safe and has no serious side affects. How else would we figure out if a new medicine works if we don't test it on a living organism? Yet we can't test humans because unlike most animals we have a family, friends, etc. Besides would you rather have a mouse tested on and killed or a man with a wife and children be tested, and eventually die from a failed drug?

Yes, but I completely disagree with cosmetics being tested on animals, as well as things like soap and shampoo. These are non-essential and it's not going to be hugely dangerous to test them on volunteers (since most cosmetics, soaps etc. use similar ingredients).

When it comes to medicines, I am happy for animals to be used if an alternative is not available, as long as some ethical guidelines are followed.

Animals should be used as sparingly as possible. They should be subjected to unnecessary suffering for minimal periods of time. Furthermore, lower level animals should be used more often than animals with a greater capacity for suffering, and when animals are optional, they should not be used.

This being said I would vastly prefer for animals to suffer the effects of a medicine before it's used on humans.

It's not like the majority of humans don't eat animals, some of which have been reared in appallingly inhumane conditions.