Why You Must Tell Your Doctor About Every Supplement and Herb You Take

Every year, millions of Americans take supplements-vitamins, fish oil, turmeric, garlic pills, St. John’s wort, ashwagandha, and more. Many believe these are harmless because they’re ‘natural.’ But here’s the truth: supplements can be just as powerful-and just as dangerous-as prescription drugs. And if your doctor doesn’t know you’re taking them, you’re playing Russian roulette with your health.

Most People Don’t Tell Their Doctors, Even When They Should

A 2018 study found that only 33% of people who take herbal or dietary supplements actually tell their doctors. That number hasn’t budged much in over a decade. Even among people with chronic conditions like diabetes, heart disease, or high blood pressure-those who are on multiple medications-less than half disclose their supplement use.

Why? Because most patients assume their doctor doesn’t care. Or worse, they think their doctor will judge them. One patient on Reddit shared: “I took garlic pills for years to lower my blood pressure. Never mentioned it. Then I almost bled out during a minor surgery.” Turns out, garlic thins the blood. Same as warfarin. And when you combine them? Risk of internal bleeding spikes.

Another common myth: “It’s just a supplement, not medicine.” But St. John’s wort? It’s used to treat depression. Turmeric? It affects liver enzymes. Ashwagandha? Can lower blood pressure and blood sugar. These aren’t harmless teas. They’re bioactive compounds with measurable effects on your body.

What Happens When You Don’t Disclose

The risks aren’t theoretical. They’re documented in peer-reviewed journals and emergency room reports.

- St. John’s wort cuts the effectiveness of birth control pills by up to 60%. Women have gotten pregnant while on the pill-because they were also taking this “natural mood booster.” - Ginkgo biloba and garlic both interfere with blood thinners like warfarin. Patients have ended up in the ER with brain bleeds after minor falls. - Green tea extract has been linked to liver damage in people taking statins. - Calcium supplements can block absorption of thyroid medication if taken at the same time. - Iron supplements make antibiotics like ciprofloxacin useless. The FDA doesn’t test supplements for safety or effectiveness before they hit shelves. That’s because of the 1994 Dietary Supplement Health and Education Act (DSHEA). The burden is on the FDA to prove something is dangerous after it’s already sold. That’s like letting a car roll off the assembly line without brakes-and only pulling it back if someone crashes.

Doctors Aren’t Always Asking-But They Should Be

Here’s the uncomfortable truth: most doctors don’t ask about supplements. A 2021 survey found only 27% of physicians felt adequately trained to discuss them. Many assume patients will volunteer the info. But patients rarely do.

One study showed that when doctors simply asked: “Do you take any vitamins, herbs, or supplements?”-disclosure jumped from 33% to 78%. That’s not magic. That’s just asking.

The problem isn’t just ignorance. It’s time. A typical doctor’s visit lasts 15 to 20 minutes. Blood pressure, cholesterol, new symptoms-those get priority. Supplements? They’re an afterthought. Unless you bring them up.

How to Talk to Your Provider-Without Getting Judged

You don’t need to be an expert. You don’t need to defend your choices. Just be honest and prepared.

• Bring the actual bottles. Don’t rely on memory. Labels list exact ingredients and dosages. Your doctor can’t guess what’s in that unlabeled capsule.
• Use simple language: “I take this for X. I didn’t think it mattered. Can you tell me if it’s safe with my other meds?”
• Don’t say “I’m taking this because my friend says it works.” Say: “I’ve been taking this for six months. I want to make sure it’s not hurting me.”
• If your provider dismisses you, ask: “Is there any research showing this interacts with my medications?”

You’re not asking for permission. You’re asking for safety.

What Your Provider Needs to Know

It’s not just about pills. It’s about everything:

• Herbs: turmeric, ginger, echinacea, milk thistle, ginseng
• Minerals: magnesium, zinc, calcium, iron
• Vitamins: D3, B12, C, E
• Probiotics and prebiotics
• Protein powders and amino acids
• Essential oils taken internally
• Teas labeled as “medicinal” (like dandelion root tea for liver support)

Even “common” things like vitamin C or fish oil can interfere with chemotherapy, blood thinners, or blood pressure meds. And if you’re on Medicare? Over 67% of beneficiaries take supplements. That’s not a small group. That’s your neighbor, your parent, your sibling.

What’s Changing-and What You Can Do Now

The tide is turning. The American Medical Association now requires medical schools to teach supplement interactions. The FDA added 70 new ingredients to its safety watchlist between 2020 and 2023. Apps like MyMedList help patients track everything they take-and share it with providers in one click.

But none of this matters if you stay silent.

Your provider isn’t trying to shut down your wellness habits. They’re trying to keep you alive. If you’re taking something to feel better, why risk making yourself sicker?

Next Steps: What to Do Before Your Next Appointment

1. Take inventory. Open your medicine cabinet. Write down every supplement, herb, and tea you take daily or weekly.

2. Check labels. Note the exact name, dose, and manufacturer. Many products hide ingredients under “proprietary blends.”

3. Bring the bottles. Don’t rely on memory. Photos of labels aren’t enough-your doctor needs to see the actual product.

4. Ask directly. At the start of your visit: “I’d like to talk about what I’m taking outside of prescriptions. Is that okay?”

5. Follow up. If your provider says “It’s fine,” ask: “Is there any reason I should stop or change it?”

You don’t need to stop your supplements. You just need to know if they’re safe with your current health situation.

Frequently Asked Questions