THCA, or tetrahydrocannabinolic acid, is a non-psychoactive compound found in raw cannabis plants. It is the precursor to THC (tetrahydrocannabinol), the main psychoactive component of cannabis. When heated, THCA converts to THC through a process called decarboxylation, which is why you don't experience the psychoactive effects of THC when consuming raw cannabis. 

Here's a more detailed explanation:

• THCA is not psychoactive:

  Unlike THC, THCA does not produce a "high" or intoxicating effect. 

• Precursor to THC:

  THCA is the acidic form of THC, meaning it contains an extra carboxyl group that prevents it from binding to the same receptors in the brain as THC. 

• Decarboxylation:

  When cannabis is heated, such as when it's smoked or vaped, the carboxyl group is removed, converting THCA into THC, the psychoactive compound. 

• Found in raw cannabis:

  THCA is naturally present in high concentrations in fresh, undried cannabis plants. 

• Potential benefits:

  While non-psychoactive, THCA may have potential therapeutic benefits, including anti-inflammatory and neuroprotective properties, although more research is needed.