Which Act defines dietary supplements and excludes them from FDA regulation?

The Dietary Supplement Health and Education Act of 1994 is the correct choice because it specifically defines dietary supplements and establishes a legal framework for their regulation. This Act allows dietary supplements to be marketed without the same stringent regulations that apply to drugs, thus excluding them from prior FDA approval processes. Under this legislation, dietary supplements are defined as products taken orally that contain dietary ingredients intended to supplement the diet, such as vitamins, minerals, herbs, and amino acids.

This Act emphasizes the responsibility of the manufacturers to ensure their products are safe and labeled correctly, while the FDA's role is primarily to take action against any unsafe dietary supplements after they reach the market. This creates a significant difference in regulatory oversight when compared to pharmaceutical drugs, which must undergo rigorous testing and approval processes before sale. The other options do not specifically pertain to dietary supplements or their regulatory status in the same way as the Dietary Supplement Health and Education Act.