Science, Tech, Math › Science The Chemistry of Theobromine Theobromine Is Chocolate's Caffeine Relative Share Flipboard Email Print Jamesmcq24/Getty Images Science Chemistry Molecules Basics Chemical Laws Periodic Table Projects & Experiments Scientific Method Biochemistry Physical Chemistry Medical Chemistry Chemistry In Everyday Life Famous Chemists Activities for Kids Abbreviations & Acronyms Biology Physics Geology Astronomy Weather & Climate By Anne Marie Helmenstine, Ph.D. Chemistry Expert Ph.D., Biomedical Sciences, University of Tennessee at Knoxville B.A., Physics and Mathematics, Hastings College Dr. Helmenstine holds a Ph.D. in biomedical sciences and is a science writer, educator, and consultant. She has taught science courses at the high school, college, and graduate levels. our editorial process Facebook Facebook Twitter Twitter Anne Marie Helmenstine, Ph.D. Updated March 14, 2019 Theobromine belongs to a class of alkaloid molecules known as methylxanthines, which naturally occur in as many as 60 different plant species and include caffeine (the primary methylxanthine in coffee) and theophylline (the primary methylxanthine in tea). Theobromine is the primary methylxanthine found in products of the cocoa tree, theobroma cacao. Effects of Theobromine on Humans Theobromine affects humans similarly to caffeine, but on a much smaller scale. Theobromine is mildly diuretic (it increases urine production), is a mild stimulant, and relaxes the smooth muscles of the bronchi in the lungs. In the human body, theobromine levels are halved between 6-10 hours after consumption. Theobromine has been used as a drug for its diuretic effect, particularly in cases where cardiac failure has resulted in an accumulation of body fluid. It has been administered with digitalis in order to relieve dilatation. Because of its ability to dilate blood vessels, theobromine also has been used to treat high blood pressure. Dangers of Theobromine Cocoa and chocolate products may be toxic or lethal to dogs and other domestic animals such as horses because these animals metabolize theobromine more slowly than humans. The heart, central nervous system, and kidneys are affected. Early signs of theobromine poisoning in dogs include nausea and vomiting, restlessness, diarrhea, muscle tremors, and increased urination or incontinence. The treatment at this stage is to induce vomiting. Cardiac arrhythmias and seizures are symptoms of more advanced poisoning. Different types of chocolate contain different amounts of theobromine. In general, theobromine levels are higher in dark chocolates (approximately 10 g/kg) than in milk chocolates (1-5 g/kg). Higher quality chocolate tends to contain more theobromine than lower quality chocolate. Cocoa beans naturally contain approximately 300-1200 mg/ounce theobromine (note how variable this is!).