THCA, HEMP, AND MARIJUANA: WHAT OKLAHOMA LAW AND NEW FEDERAL RULES REQUIRE

Oklahoma Total THC Testing, Federal Hemp Changes, and Medical Marijuana Rescheduling

Written by Rachel O. Klubeck of Gies Law Firm PLLC
Current through October 21, 2026

For years, the commercial cannabis industry has operated around a critical distinction in federal law: hemp was defined by its delta-9 THC concentration, not its total potential THC content. That distinction fueled the widespread sale of high-THCA flower marketed as federally lawful hemp, even where the product could produce intoxicating effects comparable to marijuana.

That legal landscape is changing. Congress has enacted substantial amendments to the federal definition of hemp, Oklahoma regulators have reaffirmed their position that hemp products must satisfy Total THC requirements, and the federal government has separately altered the scheduling treatment of certain state-licensed medical marijuana.

These developments create a complicated regulatory transition in which a cannabis product's legal status may depend on its chemical composition, testing methodology, intended market, licensing status, and the date of the alleged conduct.

I. THCA, THC, AND THE 2018 FARM BILL

THCA is a naturally occurring cannabinoid in raw cannabis and the chemical precursor to delta-9 THC, the principal intoxicating compound associated with marijuana. THCA itself is not significantly intoxicating in raw form. When heated through smoking, vaporization, or another process, however, THCA undergoes decarboxylation and converts into delta-9 THC.

For testing methods that separately quantify delta-9 THC and THCA, the standard conversion calculation accounts for the difference in molecular weights:

Total THC = delta-9 THC + (THCA × 0.877).

See 7 C.F.R. § 990.1 (2026) (defining “decarboxylated”).

The distinction can produce dramatically different results. Cannabis containing 0.20% delta-9 THC and 20% THCA appears to fall below a 0.3% limit if only delta-9 THC is counted. Applying the Total THC formula, however, the same product contains approximately 17.74% Total THC. That distinction became the basis of the commercial “THCA hemp” market.

The Agriculture Improvement Act of 2018, commonly called the 2018 Farm Bill, defined hemp as Cannabis sativa L. and its parts, derivatives, extracts, cannabinoids, isomers, acids, salts, and salts of isomers containing no more than 0.3% delta-9 THC on a dry-weight basis. Pub. L. No. 115-334, § 10113, 132 Stat. 4490, 4908 (codified at 7 U.S.C. § 1639o(1)). The Act also removed hemp from the Controlled Substances Act’s definition of marijuana. Id. § 12619, 132 Stat. at 5018.

The critical statutory language was “delta-9,” rather than “Total THC.” Businesses therefore argued that post-harvest cannabis containing substantial THCA remained hemp if its measured delta-9 THC satisfied the statutory threshold.

The Ninth Circuit gave support to a similar textual interpretation in the delta-8 THC context. AK Futures LLC v. Boyd St. Distro, LLC, 35 F.4th 682, 690–92 (9th Cir. 2022). But AK Futures was a Ninth Circuit trademark case involving delta-8 THC; it is not a controlling Oklahoma criminal decision holding that high-THCA cannabis must be treated as lawful hemp.

USDA’s production regulations also limit the reach of the THCA theory. They require testing by post-decarboxylation or similarly reliable methods that account for the potential conversion of THCA into THC. See 7 C.F.R. § 990.25(g). Thus, the supposed “THCA loophole” was never as simple as the proposition that any cannabis testing below 0.3% delta-9 THC was universally lawful.

II. OKLAHOMA LAW AND THE ODAFF CLARIFICATIONS

Federal hemp status does not end the inquiry in Oklahoma. The Oklahoma Department of Agriculture, Food, and Forestry (“ODAFF”) administers Oklahoma’s Industrial Hemp Program under a Total THC framework. Its testing rules require post-decarboxylation or similarly reliable methods; require laboratories to account for the potential conversion of THCA into delta-9 THC; require results reflecting the total available THC derived from THC and THCA on a dry-weight basis; and require reporting of measurement uncertainty. Okla. Admin. Code § 35:30-24-11(b)(1)–(4); see also id. § 35:30-24-2.

Separately from the cultivation-testing regulations, ODAFF has stated its position concerning products marketed as hemp. In an April 22, 2024 letter, ODAFF advised that products above the 0.3% Total THC level are not hemp and cannot be marketed as such. Letter from Okla. Dep’t of Agric., Food & Forestry, to Whom It May Concern (Apr. 22, 2024). In a January 16, 2026 Hemp Clarification Letter intended for “hemp growers, processors, handlers, and the public,” the Department reiterated that position: “Under current law hemp products are restricted to test no more than 0.3% Total THC (Total THC is measured as THC plus 87.7 percent of THCA).” Letter from Joshua Rigdon, Hemp Program Adm’r, Okla. Dep’t of Agric., Food & Forestry, to Whom It May Concern (Jan. 16, 2026) [hereinafter 2026 ODAFF Letter].

ODAFF further advises that products exceeding the applicable Total THC limits are not hemp and may not be marketed as such. An agency letter is not itself a statute or promulgated rule. The cited testing regulation addresses industrial hemp samples, and whether a particular finished product or substance qualifies for a statutory exemption or is subject to criminal penalties requires examination of the governing Oklahoma statutes and the facts, not the letter alone. Accordingly, a certificate of analysis (“COA”) showing less than 0.3% delta-9 THC does not, standing alone, establish compliance with ODAFF’s stated Total THC position or resolve the product’s classification under every applicable Oklahoma law.

Federal law does not categorically preempt stricter state regulation of hemp products. In Green Room LLC v. Wyoming, 157 F.4th 1196 (10th Cir. 2025), the Tenth Circuit rejected a federal-preemption challenge to Wyoming legislation regulating hemp products more restrictively than federal law. The court explained that the federal hemp statutes did not create the substantive individual right claimed by the plaintiffs. See also 7 U.S.C. § 1639p(a)(3)(A) (preserving more stringent state regulation of hemp production).

The distinction can also have criminal consequences. Marijuana remains a Schedule I controlled dangerous substance under Oklahoma law, subject to statutory authorizations and exemptions governing medical marijuana and other lawful conduct. See Okla. Stat. tit. 63, § 2-204(C)(12); Zou v. State, 2026 OK CR 1.

In Zou, the Oklahoma Court of Criminal Appeals affirmed criminal convictions arising from a marijuana grow that operated under a facially current OMMA license. The court held that license invalid: the grow’s OBN registration had expired, the license application identified a straw 75% owner who had no knowledge of the business, and the operation exhibited pervasive failures to comply with security, tagging, testing, and reporting requirements. The court concluded that lawful cultivation requires a valid OMMA license, including a current OBN registration, and that criminal prosecution remains available for conduct outside that authorization. Id.; see also Okla. Stat. tit. 63, § 427.6(B)(4). Although Zou did not involve THCA or hemp, it reinforces the broader point that Oklahoma’s regulated cannabis system is not blanket legalization and that conduct outside statutory authorization can remain subject to criminal prosecution.

III. CONGRESS REDEFINES HEMP AND RESTRICTS HEMP-DERIVED CANNABINOIDS

THCA flower is one of the most visible products affected by the new federal legislation, but the change reaches substantially further. The 2018 definition supported a broad market for hemp-derived products ranging from non-intoxicating CBD products to THCA flower, delta-8 THC, and other intoxicating or converted cannabinoids.

On November 12, 2025, Congress enacted Public Law 119-37. Section 781 replaces the former delta-9-only definition with a definition based on a “total tetrahydrocannabinols concentration (including tetrahydrocannabinolic acid) of not more than 0.3 percent on a dry weight basis.” Pub. L. No. 119-37, div. B, tit. VII, § 781, 139 Stat. 495, 558–60. Once fully applicable, high-THCA cannabis therefore cannot qualify as hemp merely because its existing delta-9 THC concentration falls below 0.3%.

The legislation goes beyond THCA and distinguishes intermediate from final hemp-derived cannabinoid products. The amended definition also excludes certain intermediate and final hemp-derived cannabinoid products containing cannabinoids that cannot naturally be produced by Cannabis sativa L., as well as certain naturally occurring cannabinoids that were synthesized or manufactured outside the plant. It also excludes intermediate products exceeding specified combined cannabinoid limits and intermediate products marketed or sold as final consumer products. Pub. L. No. 119-37, § 781; 7 U.S.C. § 1639o(1)(C) (as amended).

For final hemp-derived cannabinoid products, the amended federal definition establishes a separate exclusion based on a combined threshold of 0.4 milligrams per container. The calculation encompasses Total THC, including THCA, together with other cannabinoids covered by the statute's intoxicating-effects provisions. Unlike the general 0.3% dry-weight standard, this restriction operates on a per-container basis. The statute defines a “container” generally as the innermost retail packaging in direct contact with the product. Thus, the final-product threshold is measured per container, not simply as a percentage by weight. Pub. L. No. 119-37, § 781.

The restriction potentially reaches products that are not marketed as intoxicating. Executive Order 14370 specifically recognizes that some full-spectrum CBD products will once again be controlled as marijuana when Section 781 takes effect and directs Administration officials to work with Congress toward a framework preserving access to appropriate full-spectrum CBD products while restricting products posing serious health risks.

ODAFF’s January 2026 letter likewise recognizes that the federal changes extend beyond THCA flower to intermediate products, final hemp-derived cannabinoid products, and certain synthesized or manufactured cannabinoids.

The effective dates require special attention. The January 2026 ODAFF letter predates the later federal extension and therefore describes the original November 12 effective date, not the subsequently enacted two-stage timetable. Section 781 originally provided that its amendments would take effect 365 days after enactment – November 12, 2026. Pub. L. No. 119-37, § 781, 139 Stat. at 558. Congress subsequently enacted the Continuing Appropriations and Extensions Act, 2027. Section 2019 expressly provides that, until December 11, 2026, the § 781 amendments apply only to products described in 7 U.S.C. § 1639o(1)(C)(ii)(I) and (iv)(I)—the provisions addressing cannabinoids that are not capable of being naturally produced by Cannabis sativa L. Pub. L. No. 119-103, § 2019 (Sept. 2, 2026).

Accordingly, the exclusions for intermediate and final products containing cannabinoids incapable of natural production take effect November 12, 2026; except for those exclusions, the pre-amendment federal hemp definition continues to govern through December 10, 2026. The broader Total-THC definition, THCA treatment, and final-product restrictions become applicable December 11, 2026, absent further legislative action. Oklahoma’s existing Total-THC requirements, however, apply independently during that federal transition.

IV. THE TRUMP ADMINISTRATION AND THE CONTINUING SCHEDULE III DEBATE

Congress’s tightening of the hemp exception is only one side of the federal cannabis story. At the same time, the Trump Administration has pursued less restrictive treatment of marijuana through the Controlled Substances Act’s scheduling process.

On December 18, 2025, President Trump issued Executive Order 14370, Increasing Medical Marijuana and Cannabidiol Research, 90 Fed. Reg. 60,541 (Dec. 23, 2025). The Order cited the Department of Health and Human Services’ determination that medical marijuana has a currently accepted medical use and directed the Attorney General to complete the pending marijuana-rescheduling rulemaking “in the most expeditious manner in accordance with Federal law, including 21 U.S.C. 811.” The Executive Order did not itself change marijuana’s schedule.

The broader proceeding originates from DOJ’s 2024 proposal to transfer marijuana from Schedule I to Schedule III. Schedules of Controlled Substances: Rescheduling of Marijuana, 89 Fed. Reg. 44,597 (May 21, 2024). In April 2026, DOJ withdrew the August 2024 notice of hearing, terminating that stalled hearing, and issued a new notice of hearing on the 2024 proposed rule. See 91 Fed. Reg. 22,778 (Apr. 28, 2026) (withdrawal of prior hearing notice); 91 Fed. Reg. 22,777 (Apr. 28, 2026) (new notice of hearing). The hearing was held before a DEA administrative law judge from June 29 through July 15, 2026. On September 29, 2026, before issuing a recommended decision, the Chief ALJ stayed the proceeding to consider a motion by rescheduling opponents to add a recent Government Accountability Office report on federal drug-scheduling procedures to the record and to permit supplemental briefing. DEA filed its response opposing further briefing in October. As of October 21, 2026, the stay remains in place, and the broader question whether marijuana generally should be moved from Schedule I to Schedule III remains unresolved.

Separately, the DOJ took narrower action concerning specified medical-marijuana activity. In a final rule signed April 22, 2026, and published and effective April 28, 2026, the Acting Attorney General placed marijuana, marijuana extracts, and plant-derived delta-9 THC outside the hemp definition into Schedule III to the extent they are either contained in an FDA-approved drug product or subject to a state-issued license to manufacture, distribute, and/or dispense marijuana for medical purposes. Schedules of Controlled Substances: Rescheduling of Food and Drug Administration Approved Products Containing Marijuana From Schedule I to Schedule III; Corresponding Change to Permit Requirements, 91 Fed. Reg. 22,714, 22,714–15 (Apr. 28, 2026). The rule does not alter the status of hemp, and synthetic THC outside the statutory definition of marijuana remains Schedule I. Id. at 22,719.

The rule also created an expedited federal registration process for entities holding qualifying state medical-marijuana licenses. Id. at 22,721–22 (adding 21 C.F.R. § 1301.13(k)). The rule describes a federal registration pathway, not an automatic exemption from federal requirements for every state licensee. Applicants who applied within 60 days of publication were permitted to continue operating in conformity with their state licenses while their applications were pending; that window has closed. Id. at 22,722. A DEA registration issued under the rule may not exceed the scope of the underlying state license and is automatically suspended if the state license is suspended, revoked, or expires. Id. The precise effect on a particular business depends on its state license, federal registration status, activities, and applicable conditions. A petition for review challenging the rule has also been filed in the U.S. Court of Appeals for the D.C. Circuit.

Importantly, the April 2026 rule did not resolve the broader rescheduling proceeding. Marijuana falling within the final rule’s specified state-medical-license category receives Schedule III classification, subject to applicable federal controls, while the broader question whether marijuana generally should move from Schedule I to Schedule III remains pending.

Even general rescheduling would not federally legalize adult-use marijuana. Schedule III remains subject to the Controlled Substances Act, including federal registration and other controls. Rescheduling is not descheduling. State-authorized adult-use marijuana therefore presents a different federal issue from both hemp and the specified medical-marijuana activity covered by the April 2026 rule.

The Administration’s cannabis policy consequently has several moving parts: Congress is narrowing the hemp exception; the Administration is seeking to preserve an appropriate pathway for certain CBD products; specified state-licensed medical-marijuana activity has received Schedule III treatment; and the broader marijuana Schedule III proceeding remains unresolved.

V. PRACTICAL AND CRIMINAL IMPLICATIONS IN OKLAHOMA

Several conclusions follow for Oklahoma practitioners.

First, the statement that “THCA is hemp and federally legal” is not a sufficient legal analysis. During the current federal transition, the federal and Oklahoma definitions are not identical. Oklahoma uses Total THC testing for industrial hemp and ODAFF has articulated a broader product-marketing position, and Green Room confirms that the federal Farm Bill does not categorically displace stricter state regulation.

Second, laboratory methodology matters. A report showing less than 0.3% delta-9 THC may say little about Oklahoma hemp status if the same material contains substantial THCA. Counsel should determine whether the laboratory quantified delta-9 THC, THCA, or Total THC; whether testing accounted for THCA conversion; whether concentrations were reported on a dry-weight basis; and whether measurement uncertainty was estimated, reported, and properly applied. See Okla. Admin. Code §§ 35:30-24-2, 35:30-24-11(b)(1)–(4); 7 C.F.R. § 990.25(g).

Third, the date of the alleged conduct matters. Federal treatment of a cannabinoid product in October 2026 may differ materially from its treatment beginning December 11, 2026. A criminal prosecution should therefore be analyzed under the statutory and regulatory definitions actually applicable on the date of the alleged possession, manufacture, distribution, or seizure.

Fourth, regulatory status matters. The April 2026 federal rule does not create blanket protection for marijuana activity merely because an individual or business participates in Oklahoma’s medical-marijuana system. Federal Schedule III treatment is tied to a qualifying state medical-marijuana license, and federal registration is a separate requirement. Nor does the federal rule change marijuana’s Schedule I status under Oklahoma law; Oklahoma’s statutory mechanism for following federal rescheduling applies only to FDA-approved prescription drugs. See Okla. Stat. tit. 63, § 2-204(H). Zou likewise illustrates that operating outside state authorization can support criminal prosecution despite a facially current OMMA license.

Fifth, businesses holding or distributing hemp-derived cannabinoid products should evaluate their inventory before the federal amendments become applicable. A product lawfully acquired under an earlier definition of hemp does not necessarily retain that classification after the governing definition changes. Businesses should review product formulations, certificates of analysis, packaging configurations, distribution arrangements, and applicable state licensing requirements before continuing sales after the relevant effective date. The federal amendments should not be assumed to provide a general grandfathering exemption for previously manufactured or acquired inventory.

Conversely, a product labeled “hemp” does not necessarily qualify for Oklahoma’s hemp exception simply because its delta-9 THC concentration is below 0.3%.

CONCLUSION

The legal line between hemp and marijuana is undergoing its most significant revision since the 2018 Farm Bill.

The commercial THCA market developed around a federal definition focused on delta-9 THC rather than Total THC. Oklahoma already uses Total THC testing in its industrial hemp program, and ODAFF has stated that products marketed as hemp must satisfy a Total THC threshold. Congress has now enacted a broader federal definition incorporating THCA and substantially narrowing the hemp exception for certain cannabinoid products, with the broader changes presently scheduled to become applicable on December 11, 2026.

At the same time, federal marijuana policy is moving in a different direction. Specified state-licensed medical-marijuana activity has received Schedule III treatment, while the broader administrative proceeding over whether marijuana generally should move from Schedule I to Schedule III remains pending and is currently stayed. Even if that broader rescheduling occurs, however, Schedule III would not amount to federal legalization of adult-use marijuana.

The result is a significant realignment in federal cannabis policy: regulated medical marijuana is receiving less restrictive treatment, while Congress is substantially narrowing the hemp exception for cannabinoid products—including intoxicating products and some full-spectrum CBD products.

For Oklahoma practitioners, neither a “THCA hemp” label, a COA showing less than 0.3% delta-9 THC, nor federal Schedule III classification independently establishes legality under all applicable laws. The analysis turns on the substance and product involved, Total THC where applicable, testing methodology, regulatory authorization, and—particularly during the present transition—the law in effect on the date of the conduct.

PRINCIPAL AUTHORITIES AND PRIMARY-SOURCE LINKS

Cases
AK Futures LLC v. Boyd St. Distro, LLC, 35 F.4th 682 (9th Cir. 2022).
Green Room LLC v. Wyoming, 157 F.4th 1196 (10th Cir. 2025).
Zou v. State, 2026 OK CR 1.

Federal Statutes
Agriculture Improvement Act of 2018, Pub. L. No. 115-334, §§ 10113, 12619, 132 Stat. 4490.
Pub. L. No. 119-37, div. B, tit. VII, § 781, 139 Stat. 495, 558–60 (2025).
Continuing Appropriations and Extensions Act, 2027, Pub. L. No. 119-103, § 2019 (Sept. 2, 2026).
7 U.S.C. §§ 1639o, 1639p.
21 U.S.C. §§ 802(16), 811.

Federal Regulations and Executive Materials
7 C.F.R. §§ 990.1, 990.25 (2026).
21 C.F.R. § 1301.13(k) (2026).
Exec. Order No. 14,370, 90 Fed. Reg. 60,541 (Dec. 23, 2025).
89 Fed. Reg. 44,597 (May 21, 2024).
91 Fed. Reg. 22,714 (Apr. 28, 2026).
91 Fed. Reg. 22,777 (Apr. 28, 2026).
91 Fed. Reg. 22,778 (Apr. 28, 2026).

Oklahoma Statutes and Regulations
Okla. Stat. tit. 63, §§ 2-204, 427.6.
Okla. Admin. Code §§ 35:30-24-2, 35:30-24-11.

Agency Guidance
Letter from Okla. Dep’t of Agric., Food & Forestry, to Whom It May Concern (Apr. 22, 2024).
Letter from Joshua Rigdon, Hemp Program Adm’r, Okla. Dep’t of Agric., Food & Forestry, to Whom It May Concern (Jan. 16, 2026).

Other
Cong. Rsch. Serv., IF13136, Changes to the Statutory Definition of Hemp and Implications for Agricultural Policy (updated Sept. 28, 2026).

Source Links and Editorial Note
2018 Farm Bill, Pub. L. 115-334
2025 federal hemp amendments, Pub. L. 119-37
2026 effective-date legislation, Pub. L. 119-103
Congressional Research Service, hemp definition update (Sept. 28, 2026)
ODAFF April 22, 2024 THCA hemp letter
ODAFF January 16, 2026 clarification letter
Oklahoma industrial hemp testing regulation
April 28, 2026 federal medical-marijuana final rule
Executive Order 14370