What is THCA and does raw cannabis have health benefits?

THCA (tetrahydrocannabinolic acid) is the non-psychoactive precursor to THC found in raw, unheated cannabis. Decarboxylation — heating above ~105°C — converts THCA to THC by removing the carboxyl group. THCA does not bind CB1 receptors with meaningful affinity and is therefore non-intoxicating. Pharmacological properties of THCA: anti-inflammatory (COX-1/2 inhibition, PPAR-γ activation), neuroprotective (protected against MPTP-induced dopaminergic neuron loss in a Parkinson's model), antiemetic (TRPV1 and TRPA1 modulation), and antiproliferative in cancer cell lines. Raw cannabis consumption (juicing, smoothies) preserves THCA. Proponents claim benefits for inflammation, autoimmune conditions, and neuroprotection. Limitations: all evidence is preclinical; no human clinical trials exist for THCA specifically; oral bioavailability of THCA is poorly characterized; and the stability of THCA in the GI tract is uncertain. The raw cannabis movement has outpaced the science, but the preclinical pharmacology is genuinely interesting.