Bad news if you use dietary supplements: a new study has some grave words of warning for you. The study, published by Consumer Reports, claims that in many cases those dietary supplements that you think is helping you stay healthy may be doing your body tremendous harm, and you may not even be aware of it. Daily supplements is a routine for many Americans, and while most may be perfectly safe and even beneficial, there are many dangers lurking out there that are tough to spot.

The reality is that supplements are not regulated in the same way as medications, so there is a much higher risk for consumers. Producers of dietary supplements don’t have much regulation from the U.S. Food and Drug Administration or other agencies and that can allow all sorts of nasty ingredients to slip in. Supplements often have side effects that can interact with prescribed medications, and because supplements are treated as food, they don’t have to be proven safe and effective.

And labels don’t have the same requirements as medications, so what you see on the label may not be entirely accurate. As a result, a total of 23,000 go to the emergency room every year as a result of supplements that they thought were safe and turned out not to be the case.

If you want to keep yourself safe, look for the U.S Pharmacopeia (USP) label. That indicates the contents have been verified.

In addition, check with your doctor first before beginning a supplement regimen.

Consumer Reports listed 15 supplement ingredients to always avoid, as it can result in organ damage, cancer, cardiac arrest and other ailments:

Ingredient

Claimed Benefits

Risks

Aconite
Also called: Aconiti tuber, aconitum, angustifolium, monkshood, radix aconti, wolfsbane
Reduces inflammation, joint pain, gout

Nausea, vomiting, weakness, paralysis, breathing and heart problems, possibly death

Caffeine Powder
Also called: 1,3,7-trimethylxanthine

Improves attention, enhances athletic performance, weight loss

Seizures, heart arrhythmia, cardiac arrest, possibly death; particularly dangerous when combined with other stimulants

Chaparral
Also called: Creosote bush, greasewood, larrea divaricata, larrea tridentata, larreastat

Weight loss; improves inflammation; treats colds, infections, skin rashes, cancer

Kidney problems, liver damage, possibly death

Coltsfoot
Also called: Coughwort, farfarae folium leaf, foalswort, tussilago farfara

Relieves cough, sore throat, laryngitis, bronchitis, asthma

Liver damage, possible carcinogen

Comfrey
Also called: Blackwort, bruisewort, slippery root, symphytum officinale

Relieves cough, heavy menstrual periods, stomach problems, chest pain; treats cancer

Liver damage, cancer, possibly death

Germander
Also called: Teucrium chamaedrys, viscidum

Weight loss; alleviates fever, arthritis, gout, stomach problems

Liver damage, hepatitis, possibly death

Greater Celandine
Also called: Celandine, chelidonium majus, chelidonii herba

Alleviates stomachache

Liver damage

Green Tea Extract Powder
Also called: Camellia sinensis

Weight loss

Dizziness, ringing in the ears, reduced absorption of iron; exacerbates anemia and glaucoma; elevates blood pressure and heart rate; liver damage; possibly death

Kava
Also called: Ava pepper, kava kava, piper methysticum

Reduces anxiety, improves insomnia

Liver damage,exacerbates Parkinson’s and depression, impairs driving, possibly death

Lobelia
Also called: Asthma weed, lobelia inflata, vomit wort, wild tobacco

Improves respiratory problems, aids smoking cessation

Nausea, vomiting, diarrhea, tremors, rapid heartbeat, confusion, seizures, hypothermia, coma, possibly death

Methylsynephrine
Also called: Oxilofrine, p-hydroxyephedrine, oxyephedrine, 4-HMP

Weight loss, increases energy, improves athletic performance

Causes heart rate and rhythm abnormalities, cardiac arrest; particularly risky when taken with other stimulants

Pennyroyal Oil
Also called: Hedeoma pulegioides, mentha pulegium

Improves breathing problems, digestive disorders

Liver and kidney failure, nerve damage, convulsions, possibly death

Red Yeast Rice
Also called: Monascus purpureus

Lowers LDL (“bad”) cholesterol, prevents heart disease

Kidney and muscle problems, liver problems, hair loss; can magnify effect of cholesterol-lowering statin drugs, increasing the risk of side effects

Usnic Acid
Also called: Beard moss, tree moss, usnea

Weight loss, pain relief

Liver injury

Yohimbe
Also called: Johimbi, pausinystalia yohimbe, yohimbine, corynanthe johimbi

Treats low libido and erectile dysfunction, depression, obesity

Raises blood pressure; causes rapid heart rate, headaches, seizures, liver and kidney problems, heart problems, panic attacks, possibly death