IGCSE Human Biology???

Hi, I've recently discovered that I can take extra GCSEs at a local independent school - the one which stuck out most was IGCSE Human Biology. I feel it might be helpful towards my uni application to show my dedication as well as passion towards the science and I hope to work as a doctor in the future. I am fairly intelligent with target grades of 10 9s and 1 8 as well as additional maths. I am fully prepared to teach myself the whole specification with help from youtube videos, textbooks and others. I'm just wondering for anyone who's currently taking the qualification, or has taken it, is it worth it? And how would you suggest I revise for it? Any recommended revision guides. I intent to take it in Summer 2021 so I have plenty of time to self-teach. Mainly, this is to make me stick out from other applicants and I truly enjoy science. Please any help would be appreciated or any advice you have.

I haven't taken iGCSE Human Biology, but I am a current medical student. If you have 10 or more A levels where your mostly predicted 8s and 9s, then I don't really see the point of adding that GCSE. By the time you apply to uni, they won't really care very much which GCSEs you took, they just care about the grades you got. I'd recommend putting more time into volunteering, work experience and maybe medicine related online courses that would take significantly less time but something still worthy to write about in your personal statement. But if you feel really passionate about taking iGCSE Human Biology, do so by all means, it definitely wouldn't make your application worse as long as it doesn't take too much time from your other GCSEs.

i’m going to volunteer at st. john’s ambulance as part of my dofe silver and my school does work experience later in the year hopefully i’ll be in a hospital/gp.
is there any other volunteering/qualifications that might boost my application bearing in mind i’m only 14