Current research indicates that chocolate is a weak stimulant due to its content of theobromine and caffeine. However, chocolate contains too little of these compounds for a reasonable serving to create effects in humans that are on par with a coffee buzz. Aptly spoken by the pharmacologist Ryan J. Huxtable, "... [chocolate is] more than a food but less than a drug". However, chocolate is a very potent stimulant for dogs and horses; its use is therefore banned in horse-racing. Some chocolate products contain added synthetic caffeine.
Chocolate also contains small quantities of the endogenous cannabinoid anandamide and the cannabinoid breakdown inhibitors N-oleoylethanolamine and N-linolenoylethanolamine. Anandamides are produced naturally by the body, in such a way that their effects are extremely targeted (compared to the broad systemic effects of drugs like tetrahydrocannabinol) and relatively short-lived. In experiments N-oleoylethanolamine and N-linolenoylethanolamine interfere with the body's natural mechanisms for breaking down endogenous cannabinoids, causing them to last longer. However, noticeable effects of chocolate related to this mechanism in human have not yet been demonstrated.
