As previously, biochemistry is fundamental to medicine but runs alongside physiology, anatomy, pathology, clinical skills, and a little bit of history, sociology, law, ethics, etc.
I studied both (BSc and MBChB) and preferred medicine simply because it has so much breadth - it truly is the study of how people work and malfunction!
I would stop worrying about what degree interests you and focus on the job it will lead to. If you're pretty sure you want to be a laboratory research scientist then go straight for the science degree. If you want to be a doctor, medicine it is… You will only be a student for 3-6 years but the rest of your life will (hopefully!) be a lot longer.
The bottom line is that this decision doesn't matter as much as you think it does. You can study medicine as a graduate on an accelerated course post-BSc if you decide you want to be a doctor. And, if you study medicine but don't love the clinical part, then you can move in to science afterwards. Lots of medical doctors do PhDs and work part- or full-time as research scientists. Many medical schools will also let you intercalate and do a BSc (e.g. biochemistry) in one year during your medical degree.
You can go into most graduate jobs from a biochemistry degree, although often with some additional training - from research to law to marketing to investment banking. How much you earn is only determined by how much you work and what you choose to do. Medicine is unusual in that its graduates typically earn more than those from other disciplines but they also study (unpaid) for longer. The difference is not so great that it should determine your choices at this stage.