Kava, kratom, St. John's Wort, and green tea extract present health concerns

Supplements often have issues with impurities, toxins, and inaccurate labels

Consumer Reports' tests of more than 20 supplement powders and shakes in 2025 found that more than two-thirds of them contain unsafe levels of lead. Some contained 10 times the amount of lead that's considered acceptable to ingest in a day. The levels they found, in some cases, were even higher than when they tested the products 15 years earlier.

See this searchable resource about herbal therapies, including evidence and drug interactions

Memorial Sloan Kettering Cancer Center has created this searchable resource of herbal supplements to inform the public about the purported uses of herbal therapies, the existing evidence about them, their mechanism of action, and any concerns about potential herbal supplement and drug interactions.

Reporting if supplements make you ill helps FDA know what products to investigate

The US Food and Drug Administration regulates supplements like foods and can only take action about a supplement if they learn that there are problems with it after it's on the market. This website allows consumers, industry, and others to file a complaint about a product that made them ill or raised other concerns.

ConsumerLab is a watchdog site reviewing supplements for quality and recalls

The group purchases supplements and tests them for accuracy. When it tested 26 popular B vitamin supplements, it found five failed their tests because they provide either significantly less or much more of the ingredients than listed. This type of product-label mismatch can occur because the FDA does not regulate these products as it would a drug.

Supplement sales soared during the pandemic, alongside growing distrust of the health establishment, amplifying a trend that endures—even when some of the products don't even work.

Dietary supplements are regulated like foods

This hour-long 2016 documentary from Frontline, the Canadian Broadcasting Corporation, and The New York Times examined the safety of dietary supplements. It noted that this then-$30B industry (it's at least doubled since then) suffers from irregularities and impurities. It warned that many Americans are unaware of the lack of regulatory oversight over these products.

The FDA does not approve dietary supplements before they go to market

The US Food and Drug Administration does not regulate products including vitamins, probiotics, and herbal mixes as drugs due to the Dietary Supplement Health and Education Act of 1994, which amended the Federal Food, Drug, and Cosmetic Act. Because dietary supplements are regulated as a subcategory of foods, inspectors do not assess whether dietary supplements work as advertised before sale.

Read this analysis indicating which traditional stevia medical uses have scientific evidence

This research paper investigates the various uses of Stevia rebaudiana leaves and their extracts and concludes that the substances do hold significant potential for improving cardiovascular health and inflammatory disorders in adults, among several other potential applications. Its authors suggest that further research should examine safe dosage questions and chronic disease management approaches.

Artificial sweeteners are considered safe for most people, but researchers are investigating their effects on gut microbiome health.

The health benefits of matcha tea

Matcha tea has skyrocketed in popularity in recent years. Very likely due to its bright green color, which is conducive to social media post aesthetics. The tea is a powdered form of green tea, and its benefits are touted everywhere. This article examines the evidence for such health claims, finding the tea's key nutrients of theanine, chlorophyll, and caffeine did have small observable effects on study participants. Learn more here.

The US FDA issued a 2025 warning about BPC-157 and other popular peptides that are marketed for various regenerative properties.

Explore a database of generic drugs to trace their origins and identify any safety concerns.

Search this citation-heavy database of nutrition and supplement research

Explore a reference site that aggregates and summarizes peer-reviewed studies on hundreds of supplements and dietary interventions. It is ad-free and funded by subscriptions, making it a health resource without a financial stake in what you buy.

How to avoid a 'bad trip' advice includes relaxing your mind if you experience scary things and not fighting the feeling

In this video, Michael Pollan, author of "This Is Your Mind On Plants," underscores the gaps in existing understanding about the substances and recommends only taking guided experiences, for safety and help. He tackles how psychedelics work, explains microdosing and psychedelic risks, how the substances could be used to treat addiction, and the history of psychedelic stigma.

See preferred supplements across different countries in 2025, by generation

Millennials and Gen Z typically took more supplements than other age groups across vitamins, proteins, minerals, and herbal supplements, according to 2025 data from a Global Consumer Insights Survey conducted in 55 countries. Roughly two-thirds of Gen Z respondents stated they'd taken vitamins in the past 12 months. (Some users may experience a paywall.)

The dietary market is worth more than $60B

Listen to this question and answer session with the US Food and Drug Administration about dietary supplements—vitamins, minerals, probiotics and similar products people may buy in liquid, pill, or powder form. They are categorized legally as a category of food and can be legally brought to market without the FDA even knowing about it, though consumers can tell FDA about issues with the products and FDA can take action to remove dangerous or unlawful items after they're available.

The term 'superfood' is a marketing construct with no scientific or medical definition

Encompassing at least 136 plants and animals, the concept has been criticized by nutritionists for its scientific value, which has been exploited by the wellness industry for profit. Although the label has encouraged the consumption of fruits and vegetables, food variety and minimal processing remain key to a healthy diet.

Do you need a multivitamin?

In 2013, several researchers declared multivitamins dead, stating that so-called supplements had no clear benefits and might be harmful. But the science isn't so clear-cut. This article explores the question of who would benefit from...

Up to 400 milligrams of caffeine a day is considered safe

Small, frequent doses can be more effective than large amounts, though caffeine can raise blood pressure and heart rate, especially in people with hypertension. While low doses of caffeine may help with depression by stimulating dopamine, excessive caffeine, particularly from energy drinks, can lead to anxiety and heart issues.

Yes, you can take too many vitamins and they can make you sick

Too much of vitamins A, D, E, and K (which are fat-soluble) can build up in the body and cause serious health problems, including liver damage, kidney stones, and blood clotting irregularities. Excess iron and calcium can also make it harder for the body to absorb other needed nutrients.

FDA has removed black box warnings from hormone replacement therapy for menopause.

Fake sugars may disrupt metabolic health.

Supplements are only typically recommended for those with a proven deficiency

Blood tests and other dietary screening tools by clinicians and nutritionists can indicate whether someone is deficient in needed vitamins or minerals, and those results can then lead to a personalized care plan that may include supplements. Supplements can negatively interact with certain medications, so it's important to speak with your doctor about supplements before taking them.

Coffee is, generally, good for your health

While overconsumption certainly has its drawbacks—hello, not sleeping until the sun rises—on the whole, coffee is fine, even beneficial, for your health. It can even help prevent serious health conditions, like heart attacks and liver cancer.

86 commonly used drugs, including certain antidepressants, painkillers, and immunosuppressants, have different results for men and women, according to recent research.

Stevia is a plant-derived sweetener but the plant isn't approved for eating

Steviol glycosides, the sweet-tasting stuff in the plant leaves, are purified and highly processed before they end up in the food or drinks sold in stores. The US Food and Drug Administration does not allow the use of stevia leaf or crude stevia extracts in food, and the agency also bars them from being imported into the US for use as sweeteners.

Within months of a landmark 2002 study that indicated HRT harms, sales dropped by about half

In the early 2000s, Women's Health Initiative studies indicated HRT increased risk of breast cancer, heart disease, and stroke in some women—so many physicians stopped prescribing it to help with menopause symptoms. But further research has concluded that much of the elevated risk was overblown and that it was also disproportionately seen in women in their 70s who had been taking an older HRT formulation.

The American Heart Association says adults can safely drink up to five cups of coffee per day and regular consumption may improve cardiovascular health.

Ibogaine is being investigated for treating mental health issues and substance abuse

This compound, which is illegal to use in the US, has had promising results for patients who have tried it in other countries for substance abuse and mental health concerns. This psychoactive substance is not without risks, however; this TED talk points out it's also caused fatal cardiac arrhythmias and shouldn't be taken without medical supervision.

Can microdosing improve mental health?

Animal studies involving microdoses of psilocybin, the psychoactive component in magic mushrooms and ketamine, found it helped to alleviate anxiety and inflammation, an immune response that can cause damage when chronically active. Human studies are ongoing. In at least one double-blind study, where researchers and patients don't know who got a placebo versus the real thing, about half of the participants incorrectly guessed they had been given placebos.

How four types of psychedelics affect the brain

Brain imaging shows that ayahuasca, MDMA, DMT, and psilocybin profoundly affect neural activity, giving rise to higher states of introspection and consciousness. This article details exactly how each of these drugs physically affects the brain and what that means for mental health treatment. Some of these drugs quiet the brain or trigger the release of neurochemicals associated with mood regulation and learning.

Emerging research suggests that cannabis, used by about 9% of American adults as a sleep aid, may suppress rapid eye movement and lead to worse quality sleep and fewer remembered dreams.

Veterans reported single dose of ibogaine improved TBI, PTSD, anxiety, and depression

Research published in 2024 on the Central African plant-derived drug included 30 male combat vets who received ibogaine treatment in Mexico. It reported significant reductions in multiple mental health conditions and no serious side effects. Other work, however, has shown the substance can cause fatal cardiac arrhythmias, killing at least 19 people between 1990 and 2008. (Some users may encounter a paywall.)

Can you overdose on vitamins?

Many people pop a multivitamin supplement each day thinking that any excess nutrients won't hurt them. This article explains how chronic excess of any vitamin can cause toxic levels in the body. This condition is known as hypervitaminosis, and symptoms vary depending on what vitamins have achieved toxic levels of accumulation. According to this article, dietary supplements in the US are not required to submit to the FDA documentation supporting their efficacy or safety.

Oregon voters in 2020 greenlit adult use of psilocybin—the active ingredient in magic mushrooms—in state-licensed centers, and a 2026 analysis indicates the program has good safety and satisfaction data.

Mental health applications of psychedelics

Scientists are investigating psilocybin, ketamine, LSD, and MDMA (also known as ecstasy) as potential treatments for mental health issues. These drugs enable an altered state of consciousness, which can have beneficial or harmful impacts depending on the nature of the experience. Research suggests these drugs can be effective in treating substance use disorders, mental health conditions, including depression and anxiety, and psychiatric disorders, including schizophrenia.

A 49-year-old American died at an ibogaine clinic in Mexico, underscoring its risks

The man had sought out the drug to help him overcome his substance abuse disorder. Though anecdotal reports indicate potential promise, there's been no large-scale clinical trials on ibogaine's safety and efficacy. The plant is derived from a root bark named iboga and has been used for centuries by indigenous communities in Gabon, but first entered scientific consciousness in 1901 after its alkaloid was isolated from Iboga.

Vitamin D supplement pills are linked to rising cases of vitamin D toxicity in the US

Vitamin D deficiency is common. But taking Vitamin D supplements in doses exceeding 4,000 IU/day (a measurement of vitamin biological activity) for prolonged periods can raise bodily concentrations of this vitamin to dangerous values. US National Poison Data indicates that the annual average of vitamin D poisonings from 2000-05 was 196, but this rose by 1,600% to 4,535 per year for the period of 2005-11.

FDA removed its cardiovascular risk warning on testosterone products in 2025

The change came a decade after the FDA added the label. Recent work, including a gold-standard randomized trial, found that men receiving the products had similar cardiovascular risk levels as men taking placebo products. Testosterone, however, may hold other health risks, including infertility.

Two festival-goers were hospitalized after receiving trendy peptide injections, raising safety questions that may extend beyond the event.

Sugar alcohols, a type of carbohydrate used as a sweetener, may elevate risk of heart attacks and strokes.

The WHO labeled aspartame as 'possibly carcinogenic' but US regulators consider it safe

The International Agency for Research on Cancer, an arm of the World Health Organization, labeled aspartame—the artificial sweetener in Diet Coke—as one of several hundred possible cancer-causing substances in 2023. The determination was based on animal and human studies and "limited" evidence linking it to liver cancer. The WHO and US Food and Drug Administration both say the substance is safe at moderate levels. The FDA says a person weighing about 132 pounds would need to have 75 packets daily to reach an unsafe level.

Investigation finds 'influencer' dietitians paid to promote sugar, supplements on social media

A joint investigation by The Examiner and The Washington Post found that food, beverage, and supplement corporations and groups have paid registered dietitians on social media to promote content that goes against decades of scientific evidence on...

Psychedelic side effects, including worsening mental health for some patients, give pause

This article explores whether the therapeutic potential of psychedelic drug use is really as good as current research suggests. Scientists are exploring its applications for conditions ranging from the existential crisis that can accompany terminal diagnoses to chronic mental health conditions, including anxiety and PTSD.

Xylitol, a sugar alcohol, is sometimes added to foods at 1,000 times the level seen naturally in foods

This article covers the latest research in sugar alcohols and heart health. Some work indicates that after consuming sugar alcohols erythritol or xylitol people are at an elevated risk of developing blood clots, which can cause heart attacks and strokes. Both substances occur in low levels naturally in fruits and vegetables and are also produced by the human body, but as sweeteners in foods they are present at exponentially higher levels.

The spread of fraudulent stem cell treatments

All the coverage of research into promising (but often unproven) medical treatments involving stem cells has created conditions allowing some people to engage in activities regulators describe as scams. As this news article explains, attorneys general in at least seven states have taken legal action against businesses that promised (costly) stem cell treatments but allegedly engaged in fraud.

Probiotics, which are living bacteria and yeasts, are not recommended for most patients.

Natural toxins produced on plants or consumed by animals may cause food poisoning

When humans eat plants with certain natural toxins on them—including a family of toxins called aflatoxins that fungi produce on crops like peanuts and corn— they can become ill with food poisoning. Toxins can still harm humans even if animals or plants appear fine to the human eye. The World Health Organization advises that we should throw away moldy or discolored foods, refrain from eating wild plants or mushrooms that aren’t definitively nonpoisonous, and remember that just because something is “natural” it’s not always safe to eat.

Mycotoxins are toxic compounds produced by fungi—some show up in food

About a quarter of the world’s agricultural products are contaminated with mycotoxins. Some of these compounds can cause serious health problems, including cancer, so the US government has set up monitoring programs to detect them in our food and in animal feed. Humans can become ill if they eat contaminated food, but also if they ingest products from animals that had previously consumed these toxic compounds, such as milk from a cow that ate contaminated corn.

Most adults don't need a daily vitamin, and it won't extend your life

A 20-year study by the National Cancer Institute involving almost 400,000 people found that daily multivitamins did not help people live longer. In some cases, these vitamins also increased the risk of death. Although some subpopulations—such as those with documented vitamin deficiencies and pregnant individuals—should take vitamins, daily multivitamins should not be taken uniformly by adults. Instead, patients should discuss vitamins with their clinicians and consider baseline vitamin testing before starting vitamin regimens.