And yet, they do not need FDA approval.
In particular, there are 15 herbal products that you should avoid, according to a new study by Consumer Reports.
An independent panel of doctors analyzed the products to assess their safety levels.
It depends on your well-being, any existing medical conditions, how much you take, and how long you were exposed to it.
The dangers include liver damage, nausea, heart problems, inflammation, or even death.
From vitamins and probiotics to weight-loss and anti-anxiety boosters, these are the most dangerous products on the list.
A plant that comes in root form. People consume it orally. It can also be taken as a sugar pill developed by a homeopath.
WHAT IT'S MEANT TO DO: Reduces inflammation, joint pain, gout
DANGERS: Nausea, vomiting, weakness, paralysis, breathing and heart problems, possibly death
A teenage boy recently became headline news after fatally overdosing on caffeine powder. It is the raw substance found in drinks like coffee that give you a buzz. But it can be fatal.
WHAT IT'S MEANT TO DO: Improves attention, enhances athletic performance, weight loss
DANGERS: Seizures, heart arrhythmia, cardiac arrest, possibly death; particularly dangerous when combined with other stimulants
Chaparrals are a group of wild shrubs that grow in the arid South West as well as northern Mexico, and other dry parts of South America. It is sold as bark and can be made into a tea.
WHAT IT'S MEANT TO DO: Weight loss; improves inflammation; treats colds, infections, skin rashes, cancer
DANGERS: Kidney problems, liver damage, possibly death
Coltsfoot is a plant with fleshy green leaves, closely related to daisies.
It is particularly common in Europe and can be smoked.
WHAT IT'S MEANT TO DO: Relieves cough, sore throat, laryngitis, bronchitis, asthma
DANGERS: Liver damage, possible carcinogen
Also known as Ass Ear and Bruisewort, Comfrey is used as a herbal medicine and a plant fertilizer.
It can be sold as a tincture, herb, or cream.
WHAT IT'S MEANT TO DO: Relieves cough, heavy menstrual periods, stomach problems, chest pain; treats cancer
DANGERS: Liver damage, cancer, possibly death
Germander is a delicate-looking flower. It is consumed as a herb - often with honey - or as a tonic.
WHAT IT'S MEANT TO DO: Weight loss; alleviates fever, arthritis, gout, stomach problems
DANGERS: Liver damage, hepatitis, possibly death
A plant which can be infused in water, omitting a bright orange juice.
WHAT IT'S MEANT TO DO: Alleviates stomachache
DANGERS: Liver damage
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