The 0.4mg Rule Explained: Why Federal Hemp Calculations Are Changing

In November 2025, Congress rewrote the federal definition of hemp. Under the new definition, a final hemp-derived cannabinoid product can't contain more than 0.4mg of combined total THC, plus any other cannabinoids with similar effects, per container. Anything above that is no longer hemp under federal law.

After a short delay from Congress, that part of the rule takes effect on December 11, 2026.

The key word is "container." Not per serving. Not per sip. Per can, bottle, or package.

How Was Hemp Measured Before?

Since the 2018 Farm Bill, hemp has been defined by concentration: no more than 0.3% delta-9 THC by dry weight. That standard was written with the plant in mind, and it measures a percentage, not an amount.

Applied to a finished drink, the math looks very different. A 12-ounce can weighs roughly 355 grams. A 5mg dose of THC in that can works out to about 0.0014% by weight, far below the 0.3% line. That's how low-dose THC drinks, including ours, came to be sold as hemp products in the first place.

Supporters of the new rule call that a loophole. We'd call it the law as written, but we understand why it surprised people who expected hemp to mean rope, fiber, and CBD.

Why Does the New Calculation Change Everything?

The new definition changes three things at once.

It moves from a percentage to a fixed amount. Under the old rule, a larger drink could hold more THC and still meet the same concentration. Under the new rule, size doesn't matter. Every container gets the same 0.4mg ceiling.

It counts total THC, not only delta-9. THCA and other forms of THC now count toward the limit, closing off products that leaned on a single, narrow measurement.

It adds "other cannabinoids with similar effects." The FDA was directed to publish a list of which cannabinoids fall into that category. According to the Congressional Research Service, as of late September 2026, that list had not been published. So a rule taking effect in December depends partly on a list that, two and a half months out, didn't exist yet.

How Small Is 0.4mg, Really?

For context, Health Canada's lower-risk guidance suggests that people trying edible cannabis look for products that contain 2.5mg of THC or less. That's a cautious starting point, and it's still more than six times the new federal ceiling.

Our gentlest drink is a 1mg THC Bimble, a level many people describe as a quiet background shift. The 0.4mg limit is less than half of that. To reach a common 5mg serving under the new rule, you'd need twelve and a half containers.

In practice, 0.4mg isn't a lower dose limit for THC drinks. It removes them from the hemp category altogether, along with nearly every other intoxicating hemp product.

Who Pushed for This Change?

This is where the story gets a little ironic.

Senator Mitch McConnell of Kentucky championed the 2018 Farm Bill provision that legalized hemp. In 2025, he also led the effort to redefine it, saying the new language "takes us back to the original intent of the 2018 farm bill and closes this loophole." The provision ended up in the funding bill that reopened the government in November 2025.

Not everyone from Kentucky agreed. Senator Rand Paul, McConnell's fellow Kentucky Republican, tried to strip the language out, warning that it would "eliminate 100% of the hemp products in our country." His amendment failed 76 to 24. Kentucky's own state law, meanwhile, allows hemp THC drinks of up to 5mg per 12 ounces, regulated through its alcohol board.

The push also had help from outside the Capitol. In the days before the provision was added, a coalition of major alcohol trade groups, including the Beer Institute, the Distilled Spirits Council, WineAmerica, and the Wine Institute, urged Congress to "act immediately to remove hemp-derived THC products from the marketplace" until federal regulations were in place. Thirty-nine state attorneys general also asked Congress for a federal ban.

To be fair, the alcohol industry wasn't of one mind. That same week, more than 50 beer, wine, and spirits distributors told Congress not to ban these products and offered to help regulate them like alcohol. The Wine & Spirits Wholesalers of America now backs a federal bill that would do just that.

We also want to be fair about the concerns behind the rule. Lab-made intoxicating cannabinoids, products packaged to look like candy, and THC sold without age checks are real problems. Responsible cannabis beverage companies should welcome clear standards that address them. A blanket per-container cap, though, treats a carefully dosed 1mg seltzer the same way it treats those products. It's hard not to feel a little frustrated by that.

What Would a Better Calculation Look Like?

The good news is that better models already exist. Kentucky caps hemp drinks at 5mg per 12 ounces. The federal Beverage Regulatory Parity Act, introduced in August, proposes a 5mg-per-serving limit, a 21+ age standard, mandatory testing, and clear labeling.

Those are numbers built around how people actually drink. They'd keep synthetic and unregulated products off shelves while leaving room for a measured, well-labeled drink with its test results published for anyone to read. The bill hasn't passed, and we'll update this page if that changes.

So, What Does the 0.4mg Rule Mean for You?

Every Bimble, at 1mg, 5mg, and 10mg, is above the new limit. That's why our production is paused and why orders need to be placed and shipped before December 11. Our guide to ordering THC drinks online covers the timing.

This isn't a product recall, and nothing in the law asks you to return or pour out what you've bought. State and local rules vary, so check the rules where you live. For the full background, read our December federal hemp rule explainer. This article is general information, not legal advice.

We understand why lawmakers wanted rules. We just wish this one had been written with the drink in mind. We still believe there's a place at the table for a well-made Bimble, measured in milligrams that make sense.