carboxyTHC

Carboxy-THC, commonly referred to as tetrahydrocannabinolic acid (THCA), is the acidic precursor to tetrahydrocannabinol (THC) found in raw cannabis. THCA exists as THCA-A, the carboxylated form with a carboxyl group (COOH) that is removed when the compound is decarboxylated to produce psychoactive Δ9-THC. In the cannabis plant, THCA is synthesized from cannabigerolic acid (CBGA) by THCA synthase.

Unlike THC, THCA shows little to no affinity for CB1 receptors and is not intoxicating. Heating or aging drives decarboxylation, eliminating the carboxyl group as carbon dioxide and converting THCA to THC. This reaction commonly occurs during smoking, vaporization, cooking, or baking, and is temperature dependent (significant decarboxylation typically begins around 100°C and proceeds with higher temperatures and longer times).

THCA is most abundant in fresh cannabis flowers and dried material before decarboxylation, and is measured in analytical testing to track cannabinoid profiles. It can be quantified by LC-MS or GC-MS methods; decarboxylation reduces THCA levels while increasing THC content.

Research on THCA indicates potential anti-inflammatory, antiemetic, and neuroprotective properties in preclinical models, but human clinical evidence is limited. THCA is not widely approved as a medical treatment, and products containing THCA may be regulated similarly to THC-containing products because THCA can convert to THC upon heating.

Safety considerations emphasize that THCA itself is non-psychoactive; risk primarily relates to conversion to THC and resulting psychoactive effects, especially with heated products. The legal status of THCA is often tied to that of THC and can vary by jurisdiction.