GCSE's Results required for a Doctor?

It's fine. Some unis ask for all A's other B's. But tbh gcse's won't have much of an affect, As long A's you do well enough to get at 5 B's. It's mainly about getting an A in chemistry and biology at college and an A/B in maths or physics. Then there's the ukcat ( uk clinical aptitude test, I'll be taking this soon or next year if I decide on having a gap year before university), if you score really high on it they might be a little more lenient with your A level results and gcse results. You'll also need a lot of work experience, so volunteer at a hospital/hospice.