1. Infectious agents with the potential to be pathogenic.
2. Controlled substances, that is, drugs for which one must get a doctor’s prescription.
3. Multiple ingredients that, when used in combination, raise safety concerns due to possible interactions, synergistic effects, or additive effects of the various ingredients.
4. Ingredients that pose potential toxic effects, particularly when those ingredients are concentrated or in low dilution presentations (e.g., 1X, 2X, or 1C), or are not adequately controlled in the manufacturing process.
These broad categories suggest that the FDA is aiming at removing a significant number of currently available remedies from the market.