Theacrine

Theacrine, also known as 1,3,7,9-tetramethyluric acid, is a purine alkaloid found in Cupuaçu (Theobroma grandiflorum) and in a Chinese tea known as kucha (Camellia assamica var. Kucha). It shows anti-inflammatory and analgesic effects and appears to affect adenosine signalling in a manner similar to caffeine. In kucha leaves, theacrine is synthesized from caffeine in what is thought to be a three-step pathway. Theacrine and caffeine are structurally similar.



Pharmacodynamics
The exact mechanism of action of theacrine is uncertain, as no binding affinities have been published. However, animal research involving selective A1 and A2A adenosine agonists found theacrine pretreatment attenuated the expected motor depression induced by adenosine agonism, indicating that theacrine is likely an adenosine antagonist.

Administration of selective dopamine D1 and D2 antagonists demonstrate that, similarly to caffeine, theacrine's actions are in part mediated by dopamine receptors. This should not be taken as evidence that theacrine directly interacts with and/or augments dopamine receptors distinct from caffeine, as some marketers have misleadingly claimed.

Pharmacokinetics
Theacrine has half-life of 30 to 33 hours.

Safety
Theacrine has demonstrated clinical safety and non-habituating effects in healthy humans over eight weeks of daily use at up to 300 mg/day. Moreover, there was no evidence of the tachyphylaxis typical of neuroactive agents like caffeine and other stimulants.

In animal studies, theacrine has an LD50 of 810 mg/kg, compared to 265 mg/kg for caffeine.