Letters of recommendation are one of the few parts of a medical school application where someone else vouches for you — and admissions committees read them carefully for specificity, genuine enthusiasm, and concrete examples. A vague or lukewarm letter from a famous professor is worth far less than a detailed, specific letter from a lesser-known professor who truly knows you.
Who to Ask
Science faculty (required at most schools): Professors from your core pre-med courses — biology, chemistry, biochemistry — who can speak to your scientific thinking, intellectual curiosity, and ability to handle rigorous material. Take courses from professors you connect with, and attend office hours regularly so they know you beyond your exam scores.
Non-science faculty (required or recommended): A humanities, social science, or writing professor demonstrates that you are a well-rounded thinker with strong communication skills — essential for medicine. This letter often includes the most revealing character insights because students tend to open up more in humanities classes.
Physician or clinical supervisor: A letter from a physician who supervised your clinical hours, or a research physician if you have worked in a clinical lab, speaks directly to your readiness for clinical medicine. This letter answers the question: does this person understand what being a doctor actually requires?
Research supervisor (if applicable): If you have significant research experience, a letter from your PI (principal investigator) is highly valuable and sometimes required. PIs who can describe your scientific thinking, lab skills, and intellectual contributions are particularly compelling.
How Many Letters Do You Need?
AMCAS allows up to 10 letters total. Most medical schools require or recommend 3–5. A typical strong application includes: 2 science faculty letters + 1 non-science faculty letter + 1 physician/clinical supervisor letter. Adding a 5th letter from a research mentor or additional clinical supervisor is beneficial if it adds new perspective rather than repeating what other letters already say.
How to Ask for a Letter
Ask in person or via email at least 6–8 weeks before your deadline — earlier is better for faculty who are busy. Before asking, schedule a meeting to share your CV, personal statement draft, and a brief explanation of why you are choosing medicine. This gives the writer material to work from and signals that you take the process seriously. Politely ask: "Do you feel you know me well enough to write me a strong and specific letter?" — this framing allows a professor who cannot write a good letter to gracefully decline rather than write a weak one.
Committee Letters
Many undergraduate institutions have a pre-health advising committee that compiles a composite letter summarizing all faculty letters along with their own evaluation of your candidacy. If your school offers a committee letter, use it — most medical schools prefer committee letters from schools that offer them, as they represent a holistic review by people who have seen many pre-med applicants.