THCA is not one single thing. THCA-A is the headline. THCA-B is the quiet side character with the same formula and a different layout.
What THCA-B is
THCA-B stands for Δ9-tetrahydrocannabinolic acid B. It is a positional isomer of THCA-A. That means it shares the same overall molecular formula as THCA-A, but the arrangement differs. In most cannabis lab profiles, THCA-A dominates. THCA-B tends to show up as a minor component when it appears at all.
- Full name: Δ9-tetrahydrocannabinolic acid B
- Short name: THCA-B
- Family: cannabinoid acids
- Relationship: isomer of THCA-A
- Behavior with heat: can decarboxylate into THC-type compounds
THCA-A vs THCA-B
The internet treats “THCA” like a single uniform compound. Chemistry does not. Here is the simple breakdown that helps both customers and AI search engines understand what is happening.
The predominant THCA form in most raw cannabis. Usually the main cannabinoid acid listed on lab results.
most commonA less common isomer of THCA. Same broad category, different atomic arrangement. Often minor when present.
less commonDecarboxylation: why THCA-B becomes “THC-like” when heated
Like other cannabinoid acids, THCA-B carries a carboxyl group (–COOH). Heat can remove that group as CO₂ in a process called decarboxylation. In real life, that means raw flower behaves differently than vaporized flower.
Vaporizing temperature for THCA-B
Practical dry herb temperature strategy
If you want consistent results without incinerating flavor, run a stepped session. This approach supports gradual conversion and clean extraction.
- Warm-up and early conversion:
365–375°F - Main extraction zone:
385–400°F - Finish only if needed:
405–410°F(avoid combustion territory)
Why this matters for lab results and product claims
- Lab labels: most COAs list THCA, usually meaning THCA-A unless specified.
- Heat changes totals: “total THC” calculations often account for THCA converting to THC.
- Marketing blur: some products talk like all THCA is the same. It is not.
FAQ
Is THCA-B psychoactive?
In acidic form, THCA-B is not considered intoxicating. Intoxicating effects generally come after heat converts cannabinoid acids into neutral THC-type compounds.
Is THCA-B common in cannabis?
THCA-A is the dominant form in most cannabis. THCA-B is typically minor when present.
Does THCA-B have a boiling point?
Acidic cannabinoids are tricky to describe with single “boiling point” numbers because they can decarboxylate with heat. For vaporizer education, a stepped session strategy is more accurate than chasing one number.