Does Your Doctor *Really* Need to Know if You Smoke Weed (or Use Other Drugs)?

Sure, you’re an adult, capably managing your grown-up responsibilities (most of the time), but certain questions from your doctor can still make you time-travel back to childhood and fudge your answer—or even downright lie.

Case in point: questions about substance use. This includes the legal stuff, of course, like alcohol and cigarettes. But when your doc poses this query, they’re also wondering about dietary supplements (think: vitamins, herbal supplements, probiotics), semi-legal drugs like marijuana, and illegal substances, too, such as cocaine, LSD, and other drugs.

It also includes prescription medications that weren’t prescribed to you directly and supplements aimed at boosting your sexual or workout performance.

When we polled readers about their biggest health questions for our Real Talk Rx series, we found many of you wonder whether you should tell your doctor you smoke weed or otherwise be totally honest about your substance use. Here’s what our panel of MDs had to say.

So, should you tell your doctor you smoke weed? And what about other substances?

“What I always tell folks is that physicians went to medical school. We have a specialized medical knowledge that we ultimately use to keep you healthy. So sometimes there are things you may not perceive as impacting your health, but your physician may actually have some information to offer or some counseling to provide.

So I encourage people to tell their doctors about every substance. And by that I mean not just medications that are prescribed to you, but sometimes people use medications from friends or family and don’t have a prescription for it. Make sure you share that with your doctor as well.

You want to share any supplements you take. Nutritional supplements, how much caffeine and alcohol you consume, and other drugs. There are some that people may not think to share. For example there are drugs that folks use to enhance their sexual performance that they may not associate with being an actual drug or substance.”

I’m not the police, I’m your doctor. We’re not here to admonish people. There’s no judgment. We’re here to help you. —Divesh Goel, MD

“You should tell your doctor everything!

I tell patients, ‘I’m not the police, I’m your doctor.’ It usually works because I’m pretty casual, and they feel like they can tell me everything: Drug use, non-prescribed [medication] use, herbs, supplements, even if it’s a multivitamin, even if it’s folate or post- or pre-workout supplements.

Everybody can Google things or read articles, but doctors study it. We’re not here to admonish people. There’s no judgment. Our point of view is really to consult for you. We’re here to help you.”

“An open conversation with your physician is vital to help your doctor understand you as a person. And to help them understand how to best make recommendations.

If you smoked pot in college, but you haven’t done it in 30 years, that may not be as important of a discussion. Could you still tell them that you tried it once? You can, but if you’re not regularly using it or haven’t used it in the last five to 10 years, it’s probably not a huge issue.

With other substances like LSD, cocaine, and heroin, though, maybe you need to have that conversation because of the long-term effects and complications those substances could have on you in the future. Knowing that you’ve [used these] substances in the past can be really helpful for me as a doctor to make recommendations, or determine if any health complications are from heavy use in the past.

I would always recommend to share with your doctors what supplements you are taking. Many times those supplements could have interactions with prescription medications. Knowing what herbs or supplements you’re taking can also help your doctor make recommendations on whether you should stop taking them because of potential side effects with other medications.”

The takeaway

When it comes to substances—whether it’s marijuana or multivitamins—experts agree: The best policy is honesty.

Doctors have good reasons for quizzing you on your substance use—and no, it’s not just nosiness. (Nor do they generally care about the legality of what you’re using. In nearly all cases, what you tell your doctor will be protected by physician-patient confidentiality, according to The Ohio State University Wexner Medical Center, unless you’re at serious risk of hurting yourself or others.)

Rather, doctors ask because many substances have health implications. Take vitamins, for example: Some can interact with prescribed meds, according to the Mayo Clinic. Regular marijuana use may mean you’ll need more anesthesia during surgery, according to UCHealth, while using cocaine can lead to immediate side effects and potentially lasting changes to heart health, per the American Heart Association.

In other words, taking substances may directly affect your health, in the short or long term, and if you’re open with your doctor, it can help them know what to look for and better understand your overall health.

‌Confused about your health? Get answers to more common questions in our Real Talk Rx series.

—reviewed by Jennifer Gilbert, MD, MPH