Hey,
My GCSEs were poor compared to most candidates:
1 A*, 8 As and 2 Bs
But Barts only want you to have 8 As and above. They don't compare students on GCSEs. Their assessment is primarily using UKCAT and UCAS Tariff combo.
Work experience wise it was pretty average as well:
1 week shadowing consultants at hospitals
1 week volunteering at care home
3 months volunteering on hospital ward
4 years at local charity shop
Remember it is the quality not quantity!
Extra-curricular:
Football team
Badminton
DofE
Few other things, but list is not very exhaustive
I presume you are in AS?
Where else are you thinking of applying?