I took it last year through UCSD extension! It was challenging but completely manageable while working full time. I had Dr. Copp as the instructor. biochem was a hard course for me and this was my third attempt! I finally understood the way the material was being explained and finished with an A!
University of New England has a bunch of online, self paced science courses!
This is the link to their biochem one: Medical Biochemistry
I hope this helps 🙂
I used UCLA Extension. CHEM XL 153A and 153B cover all schools I've looked at. Courses are 11 weeks and the workload isn't too bad. I did mine while working full time.