Unlike drugs, supplements are regulated after they are marketed, meaning that no regulatory body evaluates the content or safety of supplements before selling them to consumers.
Dietary supplements
are a category of products that include amino acid products, enzyme supplements, herbs, and vitamins and minerals. Herbs can include plant materials, algae, and microscopic fungi. Supplements may include minerals, vitamins, or other natural biological substances and are available in a variety of shapes and sizes, including concentrates, extracts, capsules, tablets, liquids, and powders.In addition, there is no way to know the amount of active ingredient contained in the supplement, and in fact, the FDA determined in 1998 that red yeast rice containing more than trace amounts of the active ingredient could not be marketed as a supplement. Under the Dietary Supplement Health and Education Act (DSHEA), the FDA treats supplements as foods and the DSHEA defines supplements as “products that are taken orally to supplement the diet.” Some dietary supplements may not carry many risks; however, others may not only have drug interactions, but also carry risks associated with their use, even if they contain what is stated on the label. The big difference between the two is how the Food and Drug Administration (FDA) views and manages them. Look for the USP-verified brand on the bottle to make sure it's been tested by the USP; you can also look for supplements verified by the USP on their website.
Dietary supplements may make statements related to general well-being, as well as statements related to a nutrient-deficiency illness. It's extremely risky to assume that, since a supplement is “all natural”, it doesn't cause adverse effects. If the claimed effects of the product are not incompatible with the legal rules governing the labeling of foods and dietary supplements, they may be indicated on the labeling and other product leaflets, regardless of their veracity. In accordance with current legal regulations, dietary supplements cannot declare or refer to preventive, therapeutic or curative properties.
Their duty is to prove that the supplement poses a health threat, which is difficult to achieve, which means that suspicious supplements can remain in stores for years. In the Czech Republic, dietary supplements are evaluated and authorized by the Ministry of Health of the Czech Republic. However, dietary supplements usually contain at least misleading statements, as manufacturers try to evoke the impression that the product has preventive or therapeutic properties, even if it is not explicitly stated. You should do thorough research before taking any supplement and always be careful when mixing medications and supplements.