Do I need work experience to study Medicine?

This is a definite yes. It's not always a requirement from the medical schools but given that most candidates will at least have some, it becomes essential, even in getting an interview. If you do not have any, I would recommend going to see a careers officer or even a local GP. Most practices will be happy to help and are used to having students and therefore understand what you will need from it too.

Candidates with work experience have an advantage for a few reasons.

For many, these work experience placements will be their first exposure to a clinical environment, from the caring point of view. To go out and organise it in your own time shows the medical school an interest in the subject and a willingness to work hard. Also if you are continuing with your application after this exposure, it starts to show an affinity to a career in medicine and that its what you want to pursue in the future.

Perhaps the most important, or the most useful, reason to the candidate is its benefit in the interview. Most interviewers will ask about work experience, and assuming you haven't lied about any of it, it's a great chance to show yourself off and come across well. You can talk about what you did?, how you organised it?, what you learnt? and how it helped you personally?. Answering all of these questions will provide you with a complete answer and there's no need to memorise an answer before going in. Talking from memory of the experience will come across much more naturally and will engage the interviewer far better. It is useful to take detailed notes or perhaps make a diary while on work experience to reflect upon if you feel you will need it for an interview.

Ultimately work experience is essential for getting into medical school. Maybe it'll turn out to not be what you were expecting and help you in making a choice for the future. Maybe you'll want to do medicine even more, in which case having that work experience will be crucial for the application process. Either way it's a greatly rewarding thing to do with many benefits, so go out and get some!