As a person who wanted to be premed in the past and researched it quite a bit, I’ll take a shot at your question.
In terms of medical prestige, Johns Hopkins wins. However, in terms of medical school preparation I’d say the two universities are pretty comparable. They both have great premedical advising and science classes. Research is also very big on both campuses.
I’d say the only noticeable difference between the two (besides prestige) would be the atmospheres of each school. JHU is notorious for being “cutthroat.” Wash. U., however, is known to be very collaborative and friendly.
Now, please note that JHU’s reputation as “cutthroat” has to be taken with a grain of salt. A lot of information/news tends to be skewed on the internet and there’s no doubt that the intensity of JHU has been exaggerated to a degree. A lot of the “JHU ruined my life” threads are most likely from disgruntled individuals. If I were you, I’d check out the student blogs that JHU has on their admissions website. They’re really helpful in getting to know more about JHU and getting the feel for the place.
This is a bit biased, but, I’d strongly consider Wash. U. I visited and it was honestly the most welcoming campus I’ve been on yet and I’ve visited Santa Clara, UCSD, UCLA, UC Berkeley, UC Santa Cruz, and Stanford so far! The students there are extremely intelligent, but also really down to earth. So Wash. U. (IMO) beats out JHU in terms of general atmosphere.
Other misc. things you need to consider are:
Academic Rigor:
Will Your GPA Suffer? I know WUSTL has a tendency for grade deflation and I’ve heard JHU does too, but I don’t know the extent of it at either school.
Competition:
Pre-med is tough. People are trying to get As and to do that you often have to step over people (figuratively) in the academic sense. Which school provides more internships/research?
Professors:
Will the professors be more focused on their own research? Are they accessible? It’s really important to maintain good relations with anybody you learn something from because they might be the person to ask for your letter of rec.
Objective Stats:
If you REALLY want to see which one is “better” just by numbers. Just google the top undergraduate feeder schools to the medical school that you want to go to.
I think both schools are great places for pre-med and you would be blessed to go to either one for premed. What you would really need to consider is which one is a better fit for you!
Disclaimer: I’m not hundred percent concrete on all these suggestions/information. Please don’t just take my word for it. Visit and research these schools too!
Best of luck!