I don't even enter med school until the fall, but I am a nerd and my family knows it, so I've been asked this sort of thing since I was in high school. Unless they ask about something that I've read a lot about, I feel obliged to include a disclaimer (it depends on the situation whether my disclaimer is " "I have no idea but I can google that if you want, and so could you; let me know if you have any questions about what you find" or "I don't know, go to a doctor"). But I still feel obligated to at least explain what I do understand to them. The truth is, most people, even intelligent people, are naive about many medical topics, can't tell a good study from a biased one, can't tell an advertisement from a medical journal, and can't understand (at a safe level) things like the Side Effects, Interactions and Precautions sheet they get from the pharmacist with their prescription, even if the pharmacist has tried to explain some of it to them. Let alone the little inadequate warning labels put on OTC packages. If, in the middle of the night, they need to know whether or not they can take a Vicodin, Tylenol, and a Nyquil at the same time, they need to hear that it would be likely be hard on their liver to consume three acetaminophen-laced products at the same time. Most people have no idea what is in Nyquil, they just take it. If they have a bladder infection, they need to know that that leftover Z-pack in the cabinet is not going to help, nor is the cranberry juice likely to clear it up by itself. If they have nausea on the airplane and can't find any Dramamine, they need to hear that diphenhydramine (or most any of the old-school antihistamines) can serve that role admirably in a pinch. I'm certainly not going to say, "I am not trained in anti-emetic administration, here's a paper bag, try not to wretch on my travel pillow." And "No, Gramma, just because you're taking fish oil doesn't mean you can go off your beta-blockers." I could go on and on, but it comes down to the fact that having a scientific mind and even a few years of scientific curiosity still puts us in a position in which we have something to add to other people's knowledge base when they're sick, and, in my opinion, we have an obligation to do so to the extent that we can, and to be honest about the extent that we can't.