Before You Email a PhD Supervisor: What Students Wish They Had Known
I remember sitting in my Boston apartment at 2 AM, staring at a blank email draft addressed to a potential supervisor. I'd spent weeks reading their papers, drafting what I thought was the perfect pitch. What I didn't understand — what no one had told me — was that the person behind the lab website mattered infinitely more than the project description on it. And that the email I was about to send would tell them a lot about whether I'd understood that.
Most students approach the cold email as a performance: how smart can I sound, how enthusiastic can I come across, how do I signal that I read their work? Those things matter some. But what experienced PIs actually screen for is different — and understanding that changes the email entirely.
What They're Actually Looking For
You're not the first person to email this PI saying you found their work "fascinating" and your background is "a strong fit." They receive dozens of these. What they're looking for — consciously or not — is evidence that you understand what a PhD actually involves and that you've thought concretely about how your work might connect to theirs.
This means specificity is worth more than enthusiasm. "I read your 2023 paper on X and I'm curious whether approach Y you used in section 3 could be extended to Z" is more useful than three sentences about how much you admire the lab. It's not just name-dropping the paper — it's showing you read it closely enough to have a question.
It also means being honest about what you're looking for. If you want to understand their mentorship style before committing to an application, say so. Most PIs respect that directness. The ones who don't — who want you fully committed before they answer basic questions about how the lab works — are telling you something relevant about how they operate.
Before You Write Anything
The email itself should be the last step, not the first. Do the research before you reach out:
- Read their recent publications — not just the abstracts. What questions are they currently asking? Where does the work seem to be heading?
- Check their lab website for current members and alumni. Where did former students go? How long were they in the lab?
- Look at their grants (NIH RePORTER, NSF Award Search) to understand current funding and whether it's stable.
- Search for anonymous reviews from former students. Patterns across multiple reviews — not single complaints — are meaningful data.
A 2018 study in Nature Biotechnology found that the advisor relationship quality was among the strongest predictors of PhD student mental health outcomes. The time you spend researching a potential supervisor before reaching out is time invested in protecting yourself from the most avoidable PhD mistakes.
What the Email Should Actually Do
Keep it short. Three to four paragraphs is enough. A long email doesn't signal more interest — it signals that you don't know how to prioritize.
The structure that works: who you are and where you're applying from; the specific reason you're interested in this lab (not just this field); one concrete question or observation that shows you've engaged with their actual work; and a clear ask — whether that's a brief call, a meeting during a campus visit, or just a response to confirm whether they're taking students.
Don't ask what projects are available. That's fine later, but it opens a meeting too broadly and puts the burden on them to orient you from scratch. Come with something specific, even if it's just "I'd be interested in understanding more about the direction you're taking the work in your 2024 paper — is that something you'd want to discuss with a prospective student?"
After You Send It
If you get a meeting, treat it as mutual evaluation. You're deciding whether this person is the right supervisor for five to six years of your professional life — not just presenting yourself as a candidate. Prepare questions about mentorship style, feedback process, and how the PI has supported students whose career goals differ from academia. Ask to speak with current lab members. Watch how they respond to that request.
If you get no response, wait two weeks and follow up once. After that, move on. A PI who doesn't respond to a well-written inquiry from a prospective student is telling you something about their relationship to communication, which is itself relevant information.
The email is the beginning of a due diligence process, not the end of it. Use it to start a conversation, then use that conversation to find out what you actually need to know.