No. Some medical schools don't even score GCSEs and just require minimum grades in maths and English language (e.g. UCL and Imperial). Some score a fixed number of GCSEs in various ways (e.g. Birmingham) others score all of them (e.g. Oxford).
You can't make sweeping generalisations about medical school admissions. Every medical school will have their own unique and specific admissions and shortlisting criteria, and it's up to you as the applicant to research what these are and find the four which you have the best profile for. So if you have weaker GCSEs avoid GCSE heavy medical schools; if you have a weaker UCAT avoid UCAT heavy medical schools; etc, etc.