On November 12, 2025, as part of the government funding bill (H.R. 5371) to end the government shutdown, lawmakers passed a new “Farm Bill” that redefines the federal definition of “hemp” in a way that will effectively outlaw most hemp products on the market. This “hemp ban” is set to go in effect in November 2026. A bipartisan group in the House has already introduced a bill to repeal the new changes to federal hemp laws.
The 2018 Farm Bill legalized a broad range of cannabis products by removing “hemp” from the federal definitions of “marijuana” and “THC.” Since 2018, “hemp” has been defined as any part of the cannabis plant (and any and all derivatives, extracts, cannabinoids, and isomers) containing no more than 0.3% delta-9-THC. Delta-9-THC is the cannabinoid most famously associated with giving users a “high,” but it is not the only intoxicating cannabinoid found in hemp or marijuana. The 2018 Farm Bill legalized a broad variety of intoxicating cannabis products including vapes, edibles, and smoking products containing THC, CBD, and other cannabinoids.
The new hemp ban is explicitly designed to close what many in Congress perceived as a “loophole” that legalized most cannabis products and made enforcing marijuana prohibition much more difficult. As currently written, the law will outlaw most of these hemp products again by changing the definition of “hemp” under federal law in three key ways:
Change #1: Changing the Legal THC Limit From Delta-9 to “Total THC” (THC + THCA)
The law rewrites the hemp definition to require that “Total THC”, including THCA, not exceed 0.3% on a dry-weight basis. THCA is a “pre-cursor” that turns into Delta-9-THC over time or when exposed to heat. Previously, THCA did not count toward the 0.3% THC cap, however, which legalized a variety of products with high amounts of THCA and ever-changing amounts of Delta-9-THC. Now it will.
This will effectively ban all THCA products, especially high-THCA “hemp flower” that can theoretically test under 0.3% delta-9 but carry very high THCA percentages. While marijuana prosecutions are not a high priority for the government at this time, this change will make it easier to investigate and prosecute marijuana trafficking again by aligning the legal definition of “hemp” with how most law-enforcement testing actually works (those tests generally cannot distinguish THC from THCA).
Change #2: Ban on Hemp-Derived Cannabinoids “Synthesized or Manufactured Outside the Plant”
The new law also excludes from the hemp definition any “hemp-derived cannabinoid products” that contain cannabinoids “synthesized or manufactured outside the plant.” It further excludes “intermediate hemp-derived cannabinoid products,” such as distillates and isolates, when they are marketed as finished products or sold directly to consumers.
In practice, this targets products containing hemp-derived cannabinoids like Delta-8-THC, HHC, THCV, THCP, and similar cannabinoids that are found in most vapes, edibles, oils, and other products. Basically any cannabinoid that is derived from hemp through a chemical conversion in a lab setting will be excluded from the definition of hemp and thus a controlled substance. Because nearly all commercially available intoxicating “hemp cannabinoids” are produced via chemical processes starting from CBD, this provision alone would wipe out a large share of the current market.
Change #3: 0.4 mg-per-Container Cap on Intoxicating Cannabinoids
Finally, the law excludes from the definition of hemp any product that exceeds 0.4 milligrams of combined THC, THCA, or any other cannabinoids with “similar effects.” The “similar effects” language is broad; the Department of Health and Human Services will decide which other cannabinoids fall into that category.
This milligram cap is so low that it could affect not just clearly intoxicating products but also some full-spectrum CBD products that contain naturally occurring trace THC. The cap functions as a catch-all provision to sweep in any intoxicating or borderline-intoxicating product that might otherwise survive under the new textual definitions.
The hemp industry estimates that the hemp sector supports roughly 320,000 jobs, $28.4 billion in regulated market activity, and about $1.5 billion in state tax revenue, and notes U.S. Hemp Roundtable’s statement that the proposal could eliminate 95% of the U.S. hemp industry. There is a 365-day grace period before the new definitions take legal effect.