Are Dietary Supplements Really Safe?
What you need to know before popping that "healthy" pill or powder—straight from a doctor.
Photos: Classen Rafael / EyeEm / Getty Images
Thinking about taking an herbal supplement to enhance your wellness routine? While a ginger tea or reishi mushroom coconut drink here and there is a solid healthy choice, taking high doses of...well, anything, is another matter entirely.
Yes, there can be too much of a good thing (even the healthiest things). And there are some serious considerations when it comes to supplementation-especially if you have an underlying condition or take a prescription medication. (See: How Your "Healthy" Dietary Supplement Could Be Messing with Your Prescription Meds)
"Always talk to your doctor first," says Jena Sussex-Pizula, M.D., a doctor at the University of Southern California. "Taking supplements prior to a full diagnosis and discussion with your doctor can be dangerous, potentially delay needed care, and interfere with other more appropriate medications."
It's not all bad: Using supplements properly can actually be helpful. "There are so many different healing modalities available," says Dr. Sussex-Pizula. "As a primary care doctor, you get the unique chance to evaluate the entire patient, their symptoms, their medical conditions, and their medications. If after analyzing all of that, there is research data suggesting a supplement can be helpful, I discuss it with my patients." (Next read: Why This Dietitian Changed Her Mind About Supplementation)
That being said, there are some legit concerns you should take into account before popping a new pill or powder. Here's what you need to know about the safety and effectiveness of supplements.
They're not regulated.
Yes, really: The Food and Drug Administration (FDA) isn't authorized to review dietary supplement products for safety and effectiveness before they are marketed.
"Herbal supplements are actually very diverse and, unfortunately, not regulated," says Dr. Sussex-Pizula. "They're largely interpreted by patients as safe, but there are significant side effects, even toxicity of many supplements."
FYI, that means that products don't have to be proven safe. They don't have to be proven effective. They don't even have to contain the supplement they claim to be, Dr. Sussex-Pizula says. "These companies are under no obligation to do any post-market safety testing either, and they don't have to monitor for its effects on its customers." Eek.
Supplement brands can use false marketing.
Because of the lack of regulation, labels can be misleading. Technically, the FDA prohibits supplements from being marketed for the purpose of treating, diagnosing, preventing, or curing diseases-so an herbal tincture or pill can't say "lowers cholesterol" or "treats heart disease." They can, however, still make claims like "promotes a healthy response to stress" or "supports immune function."
"Supplements are often poorly labeled and confusing to patients," says Dr. Sussex-Pizula. "For example, several over-the-counter products simply labeled 'thyroid supplement' actually contain ground-up cow thyroid hormones!"
They could be contaminated.
There's also a risk of contamination, says Dr. Sussex-Pizula. "Independent congressional investigations in the United States have found high levels of pesticides, heavy metals, and undeclared other drugs/pharmaceuticals in a variety of herbal supplements."
Recent studies have found high levels of contamination in protein powders and even hidden drugs (such as Viagra and steroids) in hundreds of supplements. This all comes back to lack of regulation.
Some can have fatal consequences.
Not to scare you, but... taking the wrong supplement in the wrong circumstances could in rare cases even be fatal. "Supplements can be outright dangerous," she says. "There are multiple documented cases of patients with fulminant liver failure after taking dietary supplements. (The ones studied here include kava, ma-huang, LipoKinetix, skullcap, and bai-fang herbs). Several of these patients, unfortunately, died while awaiting a liver transplant."
Natural doesn't always mean safe.
Yes, St. John's wort, gingko, and ephedra are natural compounds, but as, Dr. Sussex-Pizula points out, so are "morphine, cocaine, box jellyfish, venom, arsenic, and ricin." Needless to say, these aren't things you want in your body.
"Plus, while the desired compound may be beneficial, the exact amounts and additional compounds in the supplement are often unknown," she says. (FYI, your protein powder may be contaminated too.)
There can be too much of a good thing.
Even something as innocuous as kale can have side effects. Yes, really: "For example, eating too much kale can be dangerous for patients on blood thinners, as it can inactivate their medication, putting them at risk for blood clots," says Dr. Sussex-Pizula. "Some otherwise safe ingredients and products can be harmful when consumed in high amounts or when taken for a long time." (Related: Can You Eat Too Much Fiber?)
The "safest" herbal supplement? Simply eating a whole foods diet, rich in micronutrients. Dr. Sussex-Pizula suggests you get your supplements "directly from the plant, fruit, or vegetable itself" to avoid any of the safety issues with supplements.