You’ve seen ads for "natural" supplements that promise to make you thinner, more muscular, smarter, or superenergized.
The fact that something is natural or herbal doesn’t mean it’s safe or that it lives up to its claims.
Dietary supplements include a wide range of products, like multivitamins, minerals, amino acids, and herbs. Some come from natural sources, like plants. Others are man-made.
You can get supplements in a variety of forms, including capsules, pills, gel tablets, liquids, tinctures, extracts, and powders.
Supplement makers do not have to test their products for safety or purity before putting them on the market.