DNP stands for “2,4-dinitrophenol,” an industrial chemical used in diet pills in the early 20th century that is now resurfacing. Over the past several years, deaths associated with DNP in weight-loss products have been reported.

A century ago DNP was recognized as dangerous and often deadly. In fact, the first Federal Food, Drug, and Cosmetic Act in 1938 made it illegal in oral products, describing it as “extremely dangerous and not fit for human consumption.” However, it is still made for pesticides and other industrial uses.

Virtually anyone can purchase the chemical and put it into a product. It is currently being marketed on the Internet as a weight-loss product. It takes very little for a lethal oral dose (as low as 4.3 mg/kg bodyweight, or about 350mg for a 180 lb person), and even skin or respiratory exposure can be toxic. DNP leads to dehydration from sweating, severely high body temperature, and cell poisoning, resulting in organ failure. There is no specific antidote for DNP poisoning, and treatment is often unsuccessful.

If you see “DNP” or “dinitrophenol” on a product label, steer clear! DNP supplements are marketed almost exclusively online, so be careful what you buy.

Updated 29 April 2015

References

Agency for Toxic Substances and Disease Registry. (2011). Dinitrophenols. Retrieved 30 April 2019 from https://www.atsdr.cdc.gov/substances/toxsubstance.asp?toxid=132

Goldgof, M., Xiao, C., Chanturiya, T., Jou, W., Gavrilova, O., & Reitman, M. L. (2014). The chemical uncoupler 2,4-Dinitrophenol (DNP) protects against diet-induced obesity and improves energy homeostasis in mice at thermoneutrality. Journal of Biological Chemistry, 289(28), 19341–19350. doi:10.1074/jbc.M114.568204

Grundlingh, J., Dargan, P. I., El-Zanfaly, M., & Wood, D. M. (2011). 2,4-dinitrophenol (DNP): A weight loss agent with significant acute toxicity and risk of death. Journal of Medical Toxicology, 7(3), 205–212. doi:10.1007/s13181-011-0162-6

Kamour, A., George, N., Gwynnette, D., Cooper, G., Lupton, D., Eddleston, M., . . . Thomas, S. H. L. (2015). Increasing frequency of severe clinical toxicity after use of 2,4-dinitrophenol in the UK: A report from the National Poisons Information Service. Emergency Medicine Journal, 32(5), 383–386. doi:10.1136/emermed-2013-203335

Lu, Y.-q., Jiang, J.-k., & Huang, W.-d. (2011). Clinical features and treatment in patients with acute 2,4-dinitrophenol poisoning. Journal of Zhejiang University SCIENCE B, 12(3), 189–192. doi:10.1631/jzus.B1000265

National Center for Biotechnology Information. PubChem Database: 2,4-dinitrophenol, CID=1493. Retrieved 30 April 2019 from https://pubchem.ncbi.nlm.nih.gov/compound/2_4-dinitrophenol

Perez, E., Gale, M., & Abe, O. (2017). 2,4-dinitrophenol DNP: A killer weight loss supplement. Chest, 152(4), A385. doi:10.1016/j.chest.2017.08.411

Tewari, A., Ali, A., O'Donnell, A., & Butt, M. S. (2009). Weight loss and 2,4-dinitrophenol poisoning. British Journal of Anaesthesia, 102(4), 566–567. doi:10.1093/bja/aep033

U.S. Food & Drug Administration. (2018). A brief history of the Center for Drug Evaluation and Research - Slide show. Retrieved 30 April 2019 from https://www.fda.gov/about-fda/virtual-exhibits-fda-history/brief-history-center-drug-evaluation-and-research-slide-show