Ranking
Most Dangerous Supplements 2026
The 15 lowest-scoring supplements we cover, most dangerous first. Several are not lawful supplements at all but drugs sold as if they were, and others are ordinary ingredients that turn risky in high doses or concentrated extracts. Each score weighs harm at usual doses, liver, kidney and heart reports, drug interactions, product quality and regulatory action.
Updated · Scores update with each page
The ranking
Tianeptine
Tianeptine is a foreign prescription antidepressant sold in US gas stations and online as a supplement. The FDA says it is not a lawful dietary ingredient, poison centre cases rose about 1,400% from 2015 to 2023, US products hold many times the foreign dose, and the DEA has proposed Schedule I control.
Score 19, grade FDMAA
DMAA (1,3-dimethylamylamine) is a synthetic stimulant once sold in pre-workouts and fat burners as "geranium extract". The FDA says products containing it are illegal, courts agreed, and it is banned in sport and in Australia, Canada and the UK. It still turns up, often as its relative 1,4-DMAA.
Score 23, grade FPhenibut
Phenibut is a Soviet-era anti-anxiety drug sold online as a nootropic. The FDA says it is not a dietary ingredient. It sedates like alcohol, tolerance builds fast, withdrawal can cause delirium and psychosis, and products range from 21 mg to over 1,100 mg a serving.
Score 25, grade FKratom
Kratom is sold like a supplement but the FDA says it cannot lawfully be one. Its alkaloids act on opioid receptors, regular use can lead to dependence and withdrawal, it has been involved in overdose deaths alongside other drugs, and products have been contaminated or spiked with concentrated 7-OH.
Score 29, grade FAmanita muscaria
Amanita muscaria, the red-and-white fly agaric, is sold as gummies, chocolates and capsules marketed as legal psychedelics. The FDA says it is not generally recognised as safe and treats foods containing it as adulterated. Products often contain other drugs or none of the active compounds.
Score 31, grade FYohimbine
Yohimbine is a stimulant drug from African tree bark, sold in US fat burners and sex-enhancement supplements. It raises heart rate and blood pressure at usual doses, most labels misstate the amount, the EU bans yohimbe in food and Canada treats yohimbine as a prescription drug.
Score 34, grade FRed yeast rice
Red yeast rice works, when it works, because it contains a statin. That brings statin side effects and interactions without a prescription, a dose you cannot know, frequent contamination with the kidney toxin citrinin, and a European ban on the way.
Score 36, grade FBitter orange
Bitter orange extract is a stimulant sold in fat burners and pre-workouts, usually with caffeine. Trials show small rises in blood pressure and heart rate, case reports include heart attacks and strokes, labels are often wrong, and Canada requires warning labels while Germany advises a low daily limit.
Score 37, grade FKava
Kava's calming effect is real, but so is its record of severe liver injury, including at least ten liver transplants in the early 2000s. It is still banned in UK food, adds to the effects of alcohol and sedatives, and product quality varies with plant variety and extraction method.
Score 43, grade DCBD
CBD does not make you high and serious harm at shop doses looks rare. But it raises liver enzymes in some healthy adults, interacts with several medicines, and products often contain more or less CBD than the label says. UK regulators advise no more than 10 mg a day.
Score 49, grade DNiacin (vitamin B3)
The niacin in a multivitamin is harmless. High-dose nicotinic acid tablets are a drug in all but name, with flushing at 30 mg, liver injury that can be severe with slow-release forms, and raised blood sugar. Two large trials found no heart benefit on top of a statin.
Score 51, grade DPre-workout
A simple pre-workout with a stated caffeine dose is about as safe as a strong coffee for healthy adults. The category as a whole scores lower because of hidden doses, stacked stimulants and a long record of products spiked with banned amphetamine-like compounds.
Score 51, grade DGreen tea extract
Green tea as a drink is safe. Concentrated extracts are another matter. High doses of the catechin EGCG cause liver enzyme rises in a measurable share of users and, rarely, severe liver injury, so the EU now caps daily intake and requires warnings.
Score 54, grade DTongkat Ali
Tongkat ali (Eurycoma longifolia) is a Southeast Asian root sold to raise testosterone. Small trials report few side effects, but EFSA found a DNA-damage signal and would not call it safe, Malaysian tests found mercury and lead, and some "male enhancement" blends hid prescription drugs.
Score 56, grade CBerberine
Berberine behaves more like a medicine than a food. Short-term trials at about 1 to 1.5 g a day show mostly stomach side effects, but it changes how the body handles several drugs, product strength is unreliable, and European regulators could not set a safe daily intake.
Score 57, grade C
How we rank supplements
Every supplement we cover has its own page with five scored factors. Safety at usual doses counts for 25%: harm at the doses people normally take and the gap to the upper intake limit. Organ toxicity reports, such as liver, kidney or heart injury, count for 20%, drug interactions for 20%, product quality in independent testing for 20%, and bans, warnings and recalls by regulators for 15%. The rubric for each is on how we score supplements.
This list shows the 15 lowest scores, most dangerous first. The order is not chosen by hand: it is the supplement scores sorted from the lowest up, and it changes when we update a page after a new warning, ban or study. That is why the text does not quote scores.
Drugs sold as supplements
Several entries near the top are not supplements in any legal sense. Tianeptine is a prescription antidepressant in other countries, sold in US petrol stations and online. Phenibut is a Soviet-era anti-anxiety drug sold as a nootropic. DMAA is a synthetic stimulant, and the active compound in red yeast rice is a statin, lovastatin, at a dose the label does not tell you. Regulators in the US, EU, UK, Canada and Australia have acted against many of these, but they are still easy to buy.
These products tend to score low on every factor at once. Doses vary widely between brands, the effects resemble those of medicines, interactions follow, and testing often finds more, less or different drugs than the label says.
Risky ingredients, not just risky products
Other entries are lawful ingredients whose risk lies in the dose or the form. Kava has a record of severe Drug-induced liver injuryLiver damage caused by a medicine, herbal product or supplement. It is usually rare and unpredictable, but it can be serious.More in the glossary. Stimulants in fat burners and pre-workouts, such as yohimbine and bitter orange, raise heart rate and blood pressure and are often mislabelled. CBD raises liver enzymes in some healthy adults and interacts with several medicines.
What the ranking does not tell you
A low score means the risks are larger, more common or less predictable than for most supplements. It is not advice on whether you should take something, and a high score elsewhere does not mean you need that product. Your own risk depends on your health, your medicines and the exact product. If you take prescription drugs, are pregnant, or have liver, kidney or heart disease, talk to your doctor or pharmacist before you start any supplement on this list.
Questions
What is the most dangerous supplement?
The product at the top of this list has the lowest score we give any supplement right now. The front of the list is made up of substances regulators do not accept as dietary ingredients, such as tianeptine, phenibut and DMAA, sold in shops and online as if they were supplements. Open each page for what regulators found and why.
Are these products legal?
It depends on the product and the country. The FDA says tianeptine and phenibut are not dietary ingredients, that kratom cannot lawfully be sold as a supplement, and that products containing DMAA are illegal, yet all of them can still be bought in the US. Others on the list are legal in some places and limited elsewhere. Kava is banned in UK food, the EU caps green tea extract and requires warnings, and Canada treats yohimbine as a prescription drug.
If a supplement is sold in a shop, has someone checked it is safe?
Not in the US and many other countries. Supplements do not need regulator approval for safety before they go on sale, and checks usually happen only after reports of harm. That is why product quality and regulatory action count for over a third of each score.
Why are some common supplements on this list?
Because the dose and form matter. The niacin in a multivitamin is harmless, but high-dose nicotinic acid tablets can injure the liver. Green tea as a drink is safe, while concentrated extracts have caused rare severe Drug-induced liver injuryLiver damage caused by a medicine, herbal product or supplement. It is usually rare and unpredictable, but it can be serious.More in the glossary. A simple pre-workout with a stated caffeine dose differs from blends with hidden or banned stimulants.
I already take one of these. What should I do?
Do not stop or change a supplement abruptly if you take it daily, especially phenibut, kratom or tianeptine, which can cause withdrawal. Talk to your doctor or pharmacist, tell them everything you take, including medicines, and ask how to stop safely if that is the right step for you.
How can I lower the risk of any supplement?
Choose single-ingredient products that state the dose in milligrams, and look for Third-party testingTesting of a supplement by an independent lab to check that it contains what the label says and is free of set contaminants.More in the glossary such as a USP Verified or NSF mark. Avoid proprietary blends, products sold to raise testosterone, burn fat or improve sex, and anything that promises drug-like effects. Check interactions with a pharmacist before combining a supplement with medicines.