theobromine

Theobromine, also known as 3,7-dimethylxanthine, is a bitter alkaloid in the methylxanthine class. It is structurally related to caffeine and theophylline and has a chemical formula of C7H8N4O2.

It occurs naturally in cacao plants (Theobroma cacao) and is the primary alkaloid in cocoa-containing foods, such as chocolate and cocoa powder. It is also found in smaller amounts in other foods and beverages that contain cacao or related plants.

Pharmacology: Theobromine acts as a central nervous system stimulant and a mild diuretic, mainly by antagonizing adenosine receptors (A1 and A2A) and by inhibiting phosphodiesterase enzymes to a lower extent than caffeine. It has a longer half-life in humans than caffeine, typically several hours, resulting in a slower, gentler stimulant effect. It can increase heart rate modestly and may have bronchodilator activity; effects are generally milder than caffeine.

Uses: In the past, theobromine has been used as a diuretic and bronchodilator. In modern consumer products, it occurs primarily as a constituent of chocolate and other cacao-derived foods; it contributes to bitterness and aroma and may influence mood slightly due to its stimulant activity. It is also studied for therapeutic potential and metabolic effects, but it is not a major pharmaceutical.

Safety: Theobromine is broadly considered safe for humans in typical dietary amounts; however, it is toxic to many animals, especially dogs and some birds, even at relatively low doses. In humans, large intakes can cause insomnia, restlessness, tachycardia, and tremors; sensitivity varies by individual.