THCA vs THC: what the law counts, and from which date
Published Oct 9, 2026
Page updated Oct 9, 2026
Short answer, as of October 8, 2026: Texas's hemp rule defines THCA (tetrahydrocannabinolic acid) as "a precursor to all tetrahydrocannabinols (THC)". The same rule notes that a lab method using heat, like gas chromatography, "converts THCA". Whether the law counts THCA depends on which rule applies and on the date:
| Rule | What it counts | From | Source |
|---|---|---|---|
| Federal hemp definition, today | "a delta-9 tetrahydrocannabinol concentration of not more than 0.3 percent on a dry weight basis". The words 'THCA' and 'tetrahydrocannabinolic acid' are not in it; it names 'acids' among the parts of the plant. | now until Dec 10, 2026 | 7 U.S.C. 1639o(1) |
| Federal hemp definition, new | "a total tetrahydrocannabinols concentration (including tetrahydrocannabinolic acid) of not more than 0.3 percent on a dry weight basis". Final products with more than 0.4 mg per container of total THC (including THCA) and other cannabinoids with THC-like effects, combined, are not hemp. | December 11, 2026 | P.L. 119-37 §781, timed by P.L. 119-103 §2019 |
| Texas | total delta-9 THC = (0.877 × THCA) + delta-9 THC, at 0.3% or less | March 31, 2026 | 25 TAC §300.101(45) |
Why the difference matters
A lab report (certificate of analysis) can show low delta-9 THC and high THCA for the same product. Under a delta-9-only test, the product can meet the hemp limit. Under a total-THC test, the THCA counts too. The certificate of analysis guide shows where each number is on the report.
The federal dates
- Until December 10, 2026: the hemp definition names delta-9 THC only.
- From December 11, 2026: the new definition counts total THC including THCA. A final product with more than 0.4 mg per container of total THC (including THCA) and other cannabinoids with THC-like effects, combined, is not hemp. P.L. 119-103 §2019 says that until December 11, 2026, the new definition applies only to products with cannabinoids the plant cannot make. That is why THCA changes on December 11, not November 12. See what changes on November 12 and December 11.
- The date may move. December 11, 2026 is also the day the current federal funding law runs out (Continuing Appropriations and Extensions Act, 2027, Sec. 106). The countdown tracks it.
State rules come first
A state can count THCA sooner than federal law. Texas has done so since March 31, 2026. Pick a state and THCA flower & pre-rolls on the map to see its rule and check date. A state with no row is not shown as legal. It means we have not checked it.
General information from primary sources — not legal advice. Checked October 8, 2026.
Sources
- 7 U.S.C. 1639o(1) — the current hemp definition (delta-9 THC, 0.3%) — checked Oct 8, 2026
- P.L. 119-37, Div. B §781 — total THC including THCA; 0.4 mg per container — checked Oct 8, 2026
- P.L. 119-103 (H.R. 6500, signed Sep 2, 2026) §2019 — most of §781 waits until Dec 11, 2026 — checked Oct 8, 2026
- 25 TAC §300.101(41) and (45) — THCA defined; Texas total delta-9 THC = (0.877 x THCA) + delta-9 THC (eff. Mar 31, 2026) — checked Oct 8, 2026
Frequently asked questions
›Does the law count THCA as THC?
It depends on the rule and the date. The federal hemp definition today names only delta-9 THC. From December 11, 2026, federal law counts total THC including THCA. Texas has counted THCA since March 31, 2026. Other states differ; check your state on the map. Not legal advice.
›What does 0.877 x THCA mean?
It is the factor in Texas's rule: total delta-9 THC = (0.877 x THCA) + delta-9 THC. The rule says the result 'shows the potential total delta-9 THC content from the sum of delta-9 THC and THCA'.
›Is THCA flower legal?
There is no single answer. Under a total-THC rule, flower whose total THC is over 0.3% by dry weight is not hemp. That rule applies in Texas today and federally from December 11, 2026. Look up your state and the date on the map, and ask a lawyer about a specific product.
This site provides general information from public sources with the statute and the check date on every row. It is not legal advice, and it never states that a product is legal without the state, the date and the source.