Not all chocolates contain the same amount of theobromine and caffeine, with the largest amount being in unsweetened baking chocolate, and the least being in white chocolate.These compounds act as stimulants that can cause tremoring, increased heart rate or arrhythmias, and seizures, smooth muscle relaxants that can cause gastrointestinal upset, and diuretics that can cause urinary incontinence.

The ingredients that pose toxicity in chocolate are theobromine and caffeine, which are both categorized into a group of compounds called methylxanthines.