wtf? for real? wow this sucks... only have 50 hours of volunteering and 0 shadowing and no ECs. didn't think I needed to be super strong in this area since I'm applying MD/PhD...
You need to have enough experience where you can point to something in it to backup your assertion that you need the MD and that it's right for you. So there's no hard amount of hours you need, but to get that kind of experience is most likely going to require a not-trivial amount of hours. Basically, you need to have some experience you can point to when answering the question "why do you want to be a doctor?" So if you want to give the "I want to help people" answer, you're not going to be very convincing if you have 50 hours of volunteering, especially if those 50 hours were earned in a few months. If you want to say something about being a leader in the community and you have no leadership experience and/or little to no volunteering, once again you're not going to convince anyone. And all of this becomes much harder if all your experience was recent (ie after you took the MCAT) because at that point you had obviously made up your mind to become a doctor, so you can't use any of that experience to convincingly explained that that was what made you want to be a doctor. And sure, you can come up with some nebulous motivation that got you interested in the first place, but then you'll have to explain why you weren't do anything clinically or service related during all that time.
The application process is like a storytelling competition. Whoever has the best stories wins. You need to tell a story about why you want to be a scientist and how good of a scientist you already are. You need to tell a story about why you want to be a doctor and why you want to help people. You need to tell a story about how you've been involved in the community and have shown leadership potential. Most important of all, you need to tell at least one story that (almost) no one else can tell.
Also, I can't state enough how important the uniqueness factor is. The majority of secondaries will ask you to state what makes you unique, and you'll be asked that same question in a number of ways at every single interview you do. At most interviews that's actually the very first question you'll be asked, often before the actual interviewing has even started (it'll come in the form of "Let's go around the room and have you guys introduce yourselves. Tell us your name, what school you're from, and a fun fact about yourself").
How many interviews did you get? What quality programs did you apply to?
6 interviews; 1 at a top 10, 1 at a top 20, 3 in the 20-40 range, and 1 non-MSTP (which was the only non-MSTP I applied to; probably would have gotten in somewhere had I applied to more non-MSTPs, but I wasn't impressed with any that I looked at). My school list was, in hindsight, too top-heavy, but not terribly so; I made a point of including a mix of schools, including a bunch that I was convinced were as close to safeties as I was gonna get because my stats were so much higher than their average stats. It's funny, but the schools that gave me interviews were mostly the ones I thought would be the least likely to give me interviews, whereas I was rejected pre-interview by most of my "safeties". Even weirder, the only MD/PhD program to not outright reject me was that top 10 (still waitlisted).
Another view of difficulty gaining admissions for otherwise qualified MD/PhD applicants:
If a person is odd, arrogant, quirky, awkward, not sociable, extremely geeky, has not demonstrated social activities, etc., can all be red flags or could preclude admission. A lack of life experiences, meaning non-academic experiences, can be taken to mean that you do not have a balanced life and that you are solely focused on academics, which at the undergraduate stage is not good. You are entering medicine- you need to have demonstrated social experiences. If the interviewer thinks that they would not want you as a doctor, you will have difficulty gaining admission. At things being equal, the sociable candidate will win.
I'd agree with this. Unfortunately for me a lot of that could describe me, and I wouldn't be at all surprised if it was why I got rejected outright after 5/6 of my interviews. That said, There were still 12 schools that rejected me without an interview, so there was obviously something wrong with my primary/secondaries as well.