Tetrahydrocannabinolic acid
![Skeletal formula of tetrahydrocannabinolic acid](/Images/godic/202502/15/Tetrahydrocannabinolicacid.svg1602.png")
![Ball-and-stick model of the tetrahydrocannabinolic molecule](/Images/godic/202502/15/Tetrahydrocannabinolic_acid_molecule_ball1602.png")
![THCA 10 mg transdermal patches from a dispensary in Colorado, United States](/Images/godic/202502/15/THCA_Transdermal_Patches1603.jpg")
Tetrahydrocannabinolic acid (THCA, Δ9-THCA, 2-COOH-THC), is a biosynthetic precursor of tetrahydrocannabinol (THC), the active component of cannabis. When purified, it forms a powder which is unstable in the presence of acids, heat, oxygen, and/or light.