1. Safety - Will it hurt you?
2. Effectiveness - Will it help you? (Does it take care of the problem it is intended to treat?)
3. What are its claims? (Does it claim to "cure"?)
4. What are the credentials of those who promote it? (Salespersons or health professions?)
5. How is it promoted? (Commercial advertisement - TV, talk show, word of mouth vs. scientific reports or medical advice)
Conventional medical treatments are the standard (mainstream) medical treatments used by most physicians. They have been scientifically tested and found to be both safe and effective. The result of such research is reported in professional journals (for physicians, scientists), which are reviewed by other doctors or scientists in the field (peer review). These conventional treatment methods have also been reviewed and approved by the federal government through the Food and Drug Administration (FDA).
Investigational treatments are still being studied in a "clinical trial," a research project that may take years to complete. Clinical trials use the scientific process to determine whether a treatment is safe and effective. A treatment may be a drug or another method of treating disease in human beings. Before it can even be tested in humans, though, a treatment is tested in the laboratory, then on animals, then, if it is determined to be safe, it is tested on humans. If it is verified to be safe, the FDA approves its use in medical care.
Alternative therapy is treatment that is promoted as a cure, yet has not been scientifically tested, or if tested, was found to be ineffective. Alternative therapies are usually promoted by those not in the medical profession. Such therapies place patients at risk because they may not be safe, and their use may keep people from using conventional treatment that could be helpful.
Complementary therapy are supportive methods used in addition to mainstream conventional therapy. These methods are not intended to cure disease but to help manage symptoms. Examples of complementary therapy include meditation, herbal teas, etc.
Quackery refers to claims of cure or prevention of diseases that have no scientific basis or are known to be false.