2,4-Dinitrophenol, often abbreviated as DNP, is a yellow crystalline solid with the chemical formula C6H4N2O5. It is a potent chemical compound that has been used for various purposes in the past, including as a pesticide and in the manufacturing of dyes and explosives. However, due to its extreme toxicity, DNP is no longer used for these purposes and is highly regulated.

DNP gained notoriety for its use as a weight loss and fat-burning supplement, although it is illegal for this purpose in many countries due to its severe health risks. It works by uncoupling oxidative phosphorylation in cells, leading to increased energy expenditure but also potentially causing overheating and organ damage. The use of DNP for any purpose other than specific chemical reactions is strongly discouraged and considered dangerous.

Handling and storage of 2,4-Dinitrophenol should be carried out with the utmost care, and it should only be used by trained professionals for legitimate chemical processes.