What you need to know first about dietary supplements

Dietary supplements include things like vitamins, minerals, herbs, or products made from plants. They can also be made from animal parts, algae, seafood, yeasts, fungus, and many other food substances or extracts. They include powdered amino acids, enzymes, energy bars, and liquid food supplements.

Some dietary supplements are formulated under careful conditions in clean, controlled laboratories and labeled accurately. Others are made less carefully, and have been found to contain none of the substances listed on their labels. And many supplements contain other substances that are not listed on their labels – fillers, different herbs, or actual drugs that are known to be able to cause harm.

If you are thinking about using dietary supplements as part of your cancer treatment, you’ll want to know more before you decide what to do. The information here will help you learn more about dietary supplements so you can make a more informed decision about using them safely.

The American Cancer Society medical and editorial content team

Our team is made up of doctors and oncology certified nurses with deep knowledge of cancer care as well as journalists, editors, and translators with extensive experience in medical writing.

Last Revised: March 31, 2015

American Cancer Society medical information is copyrighted material. For reprint requests, please see our Content Usage Policy.

Dietary Supplements: What Is Safe?