Which statement reflects a toxicology paradox?

• A. A little bit of poison can cure you
• B. Most poisons are harmless at any dose
• C. All natural substances are safe
• D. If something is natural, it cannot be toxic

Answer: (A)

The key idea here is that dose drives toxicity and even medicines can be toxins in the wrong amount. In toxicology, some substances that are dangerous at higher doses can have therapeutic effects when used in very small amounts. That’s the paradox: a little bit of poison can cure you because the same substance can be beneficial at the right dose, while too much becomes harmful. This ties to the axiom “the dose makes the poison,” and to the concept of a therapeutic window where the effective dose is far below the toxic dose. Real-world examples include how certain natural toxins or compounds are used as medicines in controlled, small doses. At larger doses, those same substances become dangerous. The other statements assume natural equals safe or that poisons are harmless at any dose, which isn’t true.