Methylxanthine

A class of naturally occurring alkaloids that includes caffeine, theobromine, and theophylline — all sharing a xanthine core structure with methyl group substitutions at different positions. Methylxanthines act as central nervous system stimulants primarily by blocking adenosine receptors, reducing the perception of fatigue. Caffeine anhydrous (Section 46) and cocoa powder (Section 72 — theobromine) are the two YNP catalogue ingredients containing methylxanthines. Caffeine is the most potent CNS stimulant of the three; theobromine (in cocoa) is milder and longer-acting.