People turn to natural remedies and supplements hoping to ease side effects from medications-whether it’s nausea from chemotherapy, hot flashes from hormone therapy, or anxiety from antidepressants. It makes sense: if something is natural, it must be safer, right? But that’s a dangerous myth. The truth is, many herbal supplements can cause their own side effects, interact dangerously with prescription drugs, or even damage your liver. And most of them aren’t tested the way pharmaceuticals are.
Why ‘Natural’ Doesn’t Mean Safe
Just because a product comes from a plant doesn’t mean it’s harmless. Think of it like this: poison ivy is natural. Deadly nightshade is natural. Both can kill you. The same goes for supplements like black cohosh, St. John’s wort, or echinacea. These aren’t harmless teas-they’re potent biological substances that affect your body’s chemistry.
The FDA doesn’t require herbal supplements to prove they’re safe or effective before they hit the shelves. Under the Dietary Supplement Health and Education Act of 1994, companies can sell these products without clinical trials. That means what’s on the label isn’t always what’s inside. A 2015 study found that up to 70% of herbal products tested contained contaminants-heavy metals, pesticides, or even prescription drugs like steroids or erectile dysfunction pills. One batch of “echinacea” was found to contain a completely different plant, and another had lead levels 20 times higher than safe limits.
Supplements That Might Help-But With Big Risks
Some natural products have shown promise in managing side effects, but only under specific conditions-and only if you know the risks.
Black Cohosh for Hot Flashes
Many women use black cohosh to reduce menopausal hot flashes. The Natural Medicines Database says only certain branded forms, like Remifemin®, are “possibly effective.” But even then, it’s not risk-free. There have been rare reports of liver damage linked to black cohosh. Experts still debate whether the herb itself is to blame or if it’s contamination. If you have a history of liver problems or are on medications that affect your liver, talk to your doctor before using it. And don’t take it long-term-most studies only looked at use for 6 months or less.
Echinacea for Cold Symptoms
Echinacea is popular for trying to shorten colds or reduce symptoms. Some small studies suggest it might help a little, but the evidence is weak. More importantly, if you’re allergic to ragweed, daisies, marigolds, or chrysanthemums, you could have a serious reaction-rashes, swelling, or even trouble breathing. It’s also not safe if you have autoimmune diseases like lupus or multiple sclerosis. Your immune system is already overactive; echinacea can make it worse.
St. John’s Wort for Low Mood
St. John’s wort is one of the most studied herbal antidepressants. Some trials show it works as well as low-dose SSRIs for mild to moderate depression. But here’s the catch: it interacts with dozens of medications. It can make birth control pills fail-by up to 24%, according to a 2000 study. It can reduce the effectiveness of antidepressants, HIV meds, blood thinners, and even chemotherapy drugs. It triggers a chemical reaction in your liver that speeds up how fast your body breaks down other drugs. That means you could be taking the right dose of your medication, but your body is flushing it out before it can work.
Ginkgo Biloba and Blood Thinners
Ginkgo is often taken for memory or circulation. But if you’re on warfarin, aspirin, or clopidogrel, it can increase your risk of bleeding. You might not notice until you bruise easily, have nosebleeds, or worse-internal bleeding. A 2019 case report described a 72-year-old man who had a brain bleed after taking ginkgo with aspirin for months. He didn’t know the two could interact.
Cranberry for UTI Prevention
Cranberry juice or pills are often used to prevent urinary tract infections. While they might help a little, they’re not a substitute for antibiotics when you have an active infection. And if you’re on blood thinners, cranberry can amplify their effect, raising bleeding risk. It’s not just juice-concentrated supplements are even more potent.
The Hidden Dangers: Interactions and Overdose
Most people don’t realize how easily supplements can clash with their medications. You might be taking a statin for cholesterol, an antidepressant, and a painkiller-all while sipping on turmeric tea and popping ashwagandha capsules. Each one could be changing how the others work.
St. John’s wort isn’t the only offender. Licorice root-common in Asian herbal formulas-can cause high blood pressure, low potassium, swelling, and even seizures in up to 3% of regular users. Bupleurum root, used in traditional Chinese medicine, has been linked to urinary bleeding and painful urination. And then there’s ephedra. Banned in the U.S. since 2004 for causing heart attacks and strokes, it still shows up in weight-loss and energy supplements sold online. The FDA received over 800 reports of serious reactions to ephedra between 1995 and 1999, including deaths in people under 40.
Even “safe” herbs can be toxic in high doses. Radix Bupleuri Chinensis, used for fever and inflammation, has a toxic dose 20 times higher than the normal clinical dose. But people don’t stop at the recommended amount. They take more because they think “more is better.” That’s when liver or kidney damage happens.
Who’s at Highest Risk?
Older adults are especially vulnerable. As we age, our liver and kidneys don’t process substances as efficiently. That means herbal compounds stick around longer in your system, building up to dangerous levels. A 70-year-old woman taking a daily supplement might have twice the concentration in her blood compared to a 30-year-old.
People with chronic conditions-liver disease, kidney failure, heart problems, or autoimmune disorders-are also at higher risk. And if you’re pregnant, breastfeeding, or undergoing cancer treatment, you should avoid most herbal supplements unless your doctor specifically approves them.
What the Evidence Really Says
Here’s the hard truth: for most herbal supplements, the evidence for reducing side effects is weak, inconsistent, or missing entirely. The Journal of the American Medical Association reviewed hundreds of studies and found that many claims about herbal remedies are based on small, poorly designed trials. Only a handful have been tested in large, randomized, placebo-controlled studies-the gold standard.
And even when a supplement shows promise, it’s often only for a specific brand or extract. Black cohosh works in one form, but not another. Ginkgo might help memory in one study, but not in another because the dosage or source was different. That’s why you can’t just say “ginkgo helps memory”-you have to know exactly which product, dose, and formulation was used.
How to Use Natural Remedies Safely
If you’re considering a supplement to manage a side effect, here’s what to do:
- Talk to your doctor or pharmacist first. Don’t assume they know what you’re taking. Bring the bottle or a photo of the label. Many doctors don’t ask about supplements because they assume patients won’t tell them.
- Check for interactions. Use a trusted tool like the Natural Medicines Database or ask your pharmacist to run a drug interaction check. Don’t rely on Google or YouTube.
- Choose reputable brands. Look for third-party testing seals like USP, NSF, or ConsumerLab. These don’t guarantee effectiveness, but they do verify what’s in the bottle matches the label.
- Start low and go slow. Even if it’s “natural,” begin with the lowest dose. Give your body time to adjust.
- Watch for new symptoms. If you start feeling dizzy, nauseous, or unusually tired after beginning a supplement, stop it. That could be the supplement-not your illness or medication.
- Report side effects. If you have a bad reaction, report it to the FDA’s Safety Reporting Portal. Your report helps protect others.
When to Avoid Natural Remedies Altogether
Don’t use herbal supplements if you:
- Are taking blood thinners, antidepressants, birth control, or chemotherapy
- Have liver or kidney disease
- Are pregnant or breastfeeding
- Have an autoimmune disorder
- Are allergic to plants in the daisy family
- Are under 18 or over 70 without medical supervision
The bottom line: natural doesn’t mean gentle. It means unregulated. And in medicine, unregulated means unpredictable.
What’s the Alternative?
Instead of guessing with herbs, work with your healthcare team to find evidence-based solutions. For nausea, there are FDA-approved anti-nausea drugs. For hot flashes, low-dose estrogen or non-hormonal options like gabapentin have solid data. For anxiety, cognitive behavioral therapy (CBT) is as effective as many supplements-with no risk of liver damage.
There’s nothing wrong with wanting to feel better. But the safest way to do it isn’t by reaching for a bottle labeled “100% natural.” It’s by asking the right questions, getting professional advice, and choosing treatments that have been tested-not just marketed.
