From omega-3s to prenatal vitamins, supplements can provide major benefits. But a new analysis from Consumer Reports reveals many ingredients found in popular supplements could seriously compromise your health.

Unlike prescription drugs and OTC medicines like ibuprofen or aspirin, "supplements are not tested for safety and efficacy by the FDA," said Ellen Kunes, who leads the health and food team at Consumer Reports. And of the more than 15,000 supplements in the US marketplace, only a few hundred undergo spot-checking by regulatory authorities, she said. 

That's pretty scary when you consider some common supplement ingredients can cause kidney and liver damage—among many other significant health issues, Kunes said.

In particular, consumers need to watch out for diet supplements (like garcinia cambogia), said Dr. Mark Moyad, director of complementary and alternative medicine at the University of Michigan Medical Center.

"Almost anything for weight loss should be a concern because most of them work by increasing blood pressure or heart rate while also trying to increase metabolism," he explains. 

Moyad looked at the Consumer Reports no-no list, and said he agrees with "virtually all" of their inclusions and concerns. He added that the levels of heavy metals like lead, arsenic, and mercury that turn up in supplements are also a big problem.

Related: Do You Know What's In Your Supplements? A New Investigation Says Probably Not.

"There are times when people may need supplements—like if a doctor recommends or prescribes something for a condition like macular degeneration," Kunes said. But it's important to understand that supplements carry risks just like other medications.  

According to the Consumer Reports analysis, there are 15 supplement ingredients in particular that you need to watch out for. 

Here are the ones to avoid, and the types of products that are most likely to contain them. 

Yohimbe

Where You Might Find It: In supplements marketed to treat low libido and erectile dysfunction, depression, and obesity

Risks: Increased BP and heart rate, headaches, seizures, liver and kidney problems, panic attacks, and death.

"Yohimbe has countless quality control issues as well as unhealthy heart effects, Moyad  said. "Why this is still allowed on the market, I have no idea."

Aconite

Where You Might Find It: In supplements marketed for the treatment of inflammation, gout, and joint pain (Try these anti-inflammatory foods instead.)

Risks: Nausea, vomiting, weakness, paralysis, breathing problems, heart problems, and death

Caffeine powder

Where You Might Find It: In supplements marketed for the treatment of attention issues, athletic performance enhancers, and weight loss supplements

Risks: Seizures, heart arrhythmia, cardiac arrest, and death—particularly when combined with other stimulants

Chaparral

Where You Might Find It: In supplements marketed for weight loss, inflammation, infections, skin rashes, and cancer

Risks: Kidney problems, liver damage, and death

Coltsfoot

Where You Might Find It: In supplements marketed to relieve coughs, sore throat, laryngitis, bronchitis, and asthma

Risks: It's a possible carcinogen, and it may also cause liver damage.

Related: Exactly What To Eat When You Have A Cold Or Flu

Comfrey

Where You Might Find It: In supplements marketed for the relief of cough,heavy periods, stomach problems, chest pain, and cancer

Risks: It's a possible carcinogen, and it may also cause liver damage.

Germander

Where You Might Find It: In supplements marketed for weight loss, fever, arthritis, gout, and stomach problems

Risks: Liver damage, hepatitis, and possibly death

Greater celandine

Where You Might Find It: In supplements marketed to treat stomachaches

Risks: Liver damage (Here are 4 supplements that don’t mix with meds.)

Green tea extract powder

Where You Might Find It: In supplements marketed for weight loss

Risks: Dizziness, ringing in the ears, worsening glaucoma or anemia, liver damage, elevated blood pressure, and death

Kava

Where You Might Find It: In supplements marketed to reduce anxiety or insomnia

Risks: Liver damage, worsening depression or Parkinson's disease, and impaired driving

Lobelia

Where You Might Find It: In supplements marketed to reduce respiratory problems and help you quit smoking

Risks: Nausea, vomiting, diarrhea, tremors, rapid heartbeat, confusion, seizures, hypothermia, coma, and death

Methylsynephrine

Where You Might Find It: In supplements marketed for weight loss, increased energy, and improved athletic performance

Risks: Heart rate and rhythm abnormalities and cardiac arrest, especially when combined with other stimulants. This is one of those weight lossingredients Moyad said to watch out for.

Pennyroyal oil

Where You Might Find It: In supplements marketed for breathing problems or digestion issues

Risks: Liver or kidney failure, nerve damage, convulsions, and death

Red yeast rice

Where You Might Find It: In supplements marketed to lower cholesterol or prevent heart disease. However, this is the one ingredient on the Consumer Report list that Moyad doesn't agree with.

 "Red yeast rice has undergone countless clinical trials showing that it could be an option for statin-intolerant patients," he said. (Here are 12 foods that lower cholesterol naturally.)

Risks: Kidney and muscle issues, liver problems, hair loss, and heart issues

Usnic acid

Where You Might Find It: In supplements marketed for weight loss and pain relief

Risks: Liver injury

This article originally appeared on Prevention.com.