Federal hemp THC limits take effect November 12, 2026

On November 12, 2026, the federal definition of hemp narrows. Section 781 of Public Law 119-37 amends the definition in the Agricultural Marketing Act of 1946 so that the 0.3 percent THC ceiling counts tetrahydrocannabinolic acid, caps finished consumer products at 0.4 milligrams of total THC per container, and excludes cannabinoids that were synthesized or manufactured outside the plant. The statute sets the change to take effect "365 days after the enactment of this Act", and the Act was enacted on November 12, 2025.

That date has not arrived. As of this writing the 2018 Farm Bill definition still governs, and products that comply with it remain federally lawful hemp. This brief sets out what the amended text actually says, which products it reaches, what it explicitly carves out, and what it leaves untouched. Every quotation below is taken from the enrolled text of the law.

What Section 781 actually changed

Section 781 does not create a new prohibition in the Controlled Substances Act. It rewrites the definition of "hemp" in 7 U.S.C. 1639o. That distinction matters, because the 2018 Farm Bill worked by carving hemp out of the CSA definition of marijuana. Narrowing what counts as hemp automatically widens what remains a controlled substance, without Congress needing to schedule anything.

The 2018 mechanism is worth stating plainly, because the whole structure depends on it. Congress did not legalize hemp by permitting it. It legalized hemp by defining it out of the controlled-substance category, so that anything meeting the definition simply was not the regulated thing. Every hemp-derived product sold since then has relied on that definitional exit. Section 781 does not close the exit. It moves the door.

The amendment redesignates the existing paragraphs of the definitions section and replaces the definition of hemp entirely. It also adds new defined terms that did not previously exist in the statute: "industrial hemp", "hemp-derived cannabinoid product", "intermediate hemp-derived cannabinoid product", and "container". The last three do most of the operative work, because they let the statute apply different rules to bulk material, to intermediate preparations, and to what a consumer actually buys off a shelf.

The practical consequence of a definitional amendment is that no agency has to act for the change to bite. On the effective date, material that no longer satisfies the definition stops being hemp as a matter of law. Products outside the definition are not granted a new legal status; they revert to whatever status they would have had without the carve-out.

The 0.3 percent test now counts THCA

The headline number is unchanged at 0.3 percent, but what gets measured against it is not. The amended definition excludes material containing more than 0.3 percent "combined total of" two things: "total tetrahydrocannabinols (including tetrahydrocannabinolic acid)" and "any other cannabinoids that have similar effects (or are marketed to have similar effects) on humans or animals as a tetrahydrocannabinol (as determined by the Secretary of Health and Human Services)".

Under the 2018 standard, compliance was commonly measured on delta-9 THC alone. THCA is the acidic precursor that converts to delta-9 THC when heated, and material high in THCA but low in delta-9 THC could test as compliant hemp while behaving as something else once smoked or vaporized. Counting THCA toward the threshold closes that gap by measurement rather than by enforcement.

Counting THCA also changes what a compliance test has to measure. A total-tetrahydrocannabinols figure requires accounting for the acidic precursor that converts on heating, rather than reporting the delta-9 fraction of an unheated sample. Laboratories already run both methods, so the change is less a technical problem than a change in which number determines legal status.

The second clause is open-ended by design. It delegates to the Secretary of Health and Human Services the question of which additional cannabinoids have, or are marketed as having, effects similar to a tetrahydrocannabinol. That means the reach of the definition can expand administratively without a further act of Congress. It also means the marketing of a product is itself relevant evidence: a cannabinoid sold on the promise of intoxicating effect can be captured on that basis, independent of its pharmacology.

The 0.4 milligram per container cap has the widest reach

For finished consumer goods, the operative limit is not the percentage. It is a flat ceiling. The amended definition excludes any final hemp-derived cannabinoid product containing "greater than 0.4 milligrams combined total per container" of total tetrahydrocannabinols including THCA, plus any other cannabinoids the HHS Secretary identifies as having similar effects.

This is a per-container limit, not a per-serving or per-percentage limit. A large-volume product with a very low THC concentration can satisfy 0.3 percent by weight and still exceed 0.4 milligrams in the package. Because the cap is absolute rather than proportional, it binds hardest on exactly the categories that grew fastest under the 2018 definition: beverages, edibles, tinctures, and vape cartridges sold directly to consumers.

The two tests operate together rather than as alternatives. Plant material and bulk preparations are measured against the 0.3 percent concentration threshold. A finished product headed for a retail shelf must satisfy the concentration test and the per-container milligram ceiling. A product can fail on the second while passing the first, which is why the milligram cap, not the percentage, is the provision that determines the legal status of most consumer goods.

Cannabinoids made outside the plant are excluded outright

The amended definition excludes final hemp-derived cannabinoid products containing "cannabinoids that are not capable of being naturally produced by a Cannabis sativa L. plant". It separately excludes cannabinoids that "are capable of being naturally produced by a Cannabis sativa L. plant" but "were synthesized or manufactured outside the plant".

Read together, those two clauses reach both novel synthetics and molecules that occur naturally but were produced by chemical conversion. Delta-8 THC manufactured by converting hemp-derived CBD falls in the second category: the molecule occurs in the plant, but the commercial supply is made outside it. The exclusion turns on the manufacturing pathway, not on the identity of the end molecule.

What counts as a container

The statute defines the term rather than leaving it to interpretation. A "container" is "the innermost wrapping, packaging, or vessel in direct contact with a final hemp-derived cannabinoid product in which the final hemp-derived cannabinoid product is enclosed for retail sale to consumers, such as a jar, bottle, bag, box, packet, can, carton, or cartridge". The definition expressly excludes "bulk shipping containers or outer wrappings that are not essential for the final retail delivery or sale".

The innermost-packaging rule forecloses the obvious workaround of subdividing a product into many small units inside one carton and measuring the carton. Congress also directed the Food and Drug Administration to publish "additional information and specificity about the term container" within 90 days of enactment, alongside lists of naturally producible cannabinoids, naturally occurring tetrahydrocannabinol-class cannabinoids, and other cannabinoids with similar effects.

What the statute carves out

Three carve-outs sit in the amended text.

Industrial hemp is defined separately and is not subject to the cannabinoid-product limits. The term covers hemp grown for the stalk and fiber, for grain, seed, oil, cake, nut, or hull, for microgreens and other edible leaf products from immature plants, for research at an institution of higher education or an independent research institute where the plant does not enter commerce, and for viable seed produced solely to make those materials.

Approved drugs are excluded. The definition of hemp-derived cannabinoid product "does not include a drug that is the subject of an application approved under subsection (c) or (j) of section 505 of the Federal Food, Drug, and Cosmetic Act". That is the pathway under which FDA has approved a cannabidiol drug product, so prescription cannabinoid medicines are unaffected.

Intermediate products remain hemp only while they stay intermediate. The definition excludes "any intermediate hemp-derived cannabinoid products which are marketed or sold as a final product or directly to an end consumer for personal or household use". Bulk material moving between manufacturers is treated differently from the same material sold to the public.

Is CBD affected

CBD is not banned by name anywhere in Section 781. A CBD product is affected only through the general limits: the 0.4 milligram per container cap on total THC and similar-effect cannabinoids, and the exclusion of cannabinoids synthesized or manufactured outside the plant.

In practice this means the analysis is product-specific rather than category-wide. A CBD product that carries trace THC above the container cap falls outside the definition even though CBD itself is not the target. A CBD isolate produced by extraction rather than conversion, in a container holding no more than 0.4 milligrams of total THC, is not reached by these clauses. Because the HHS Secretary can designate additional cannabinoids as having similar effects, the boundary is not fixed.

What this does not change

Section 781 amends agricultural law. It does not amend any state medical or adult-use cannabis statute, and it does not alter the state programs this site tracks. A state medical cannabis program operates under state law on cannabis that was never federally lawful hemp to begin with, so the hemp definition is not the provision that governs it.

The amendment also does not reschedule cannabis, change federal employment rules, or affect the separate federal rescheduling proceeding. Its effect is confined to what may be sold as hemp and hemp-derived cannabinoid product under federal law.

State law remains an independent constraint in both directions. A number of states already regulate or prohibit intoxicating hemp products more strictly than the federal floor, and those rules apply regardless of the federal effective date. A product can be lawful under the amended federal definition and still be prohibited where it is sold. The federal definition sets a ceiling on what may be treated as hemp nationally; it does not set a floor that states must permit.

Nor does the amendment disturb the USDA domestic hemp production program, which governs licensing, sampling, and testing for growers. Cultivation rules continue to operate under their existing framework. What changes is the definitional boundary those rules are measured against.

What to watch before November 12, 2026

Three things determine how much the amended definition actually reaches.

The first is the FDA lists. The statute required publication within 90 days of enactment, and the list of cannabinoids with similar effects to tetrahydrocannabinol is the provision that sets the outer boundary of the definition.

The second is intervening legislation. The effective date is 365 days out precisely because Congress left itself room, and hemp provisions have moved in subsequent farm bill negotiations. The date is fixed in statute unless a later law changes it.

The third is state action. States that have deferred to the federal definition may need to decide whether their own statutes track the new one automatically or require amendment.

This page reflects the enrolled text of Public Law 119-37 as reviewed on the date shown above. Patients and businesses affected by these limits should confirm current federal and state requirements with the relevant regulator or with counsel before making decisions.

Related reading

• Hemp-derived cannabinoids: how mmjnow tracks CBD, delta-8, delta-10, topicals, and THC beverages by product type
• Delta-8 THC: the conversion pathway that Section 781 addresses directly
• CBD: product-type overview and state-level treatment
• Federal cannabis status in 2026: Schedule I, the proposed Schedule III rule, SAFE Banking, and DOJ enforcement, which move on a separate track from the hemp definition
• The 2026 state cannabis legislation tracker: state bills that interact with the federal hemp floor