Millions of Americans who rely on the cannabis compound CBD to ease arthritis, anxiety, sleep problems or plain old boredom could soon be in for a shock. By November, many CBD creams, tinctures, gummies and beverages are to be swept from shelves nationwide, under a provision of the legislation that reopened the U.S. government last fall.

Some states are already curtailing sales. New Jersey’s ban goes into effect in April.

The law is the latest contortion in a years-long effort by policymakers to figure out how to regulate an array of CBD products made from the hemp plant, a legal variety of cannabis. They are sold in gas stations, convenience stores and smoke shops, as well as in boutique pet food stores, spas, and, of course, online. Analysts have projected sales for wellness and recreational products with CBD, or cannabidiol, to range somewhere between $8.5 and $13 billion in 2026.

The pending restrictions have ignited a furious backlash by consumers, small business owners, manufacturers and growers, culminating in a flurry of bipartisan bills sponsored by some odd political bedfellows, attempting to scale back what many characterize as the law’s extreme overcorrection.

Under the new law, hemp-derived products must contain almost no detectable trace of THC, the best-known psychoactive compound in cannabis. Industry insiders predict that the requirement will extinguish much of the CBD market, because so many products include at least some THC.

In preparation, this month the Food and Drug Administration must list all synthetic and naturally occurring cannabis compounds with THC-like intoxicating effects, for potential inclusion under the ban.

The current conflict took root in 2018, when Congress legalized hemp, which is rich in CBD. Natural CBD is not psychoactive, but hemp does have traces of THC.

(In contrast, marijuana, another variety of cannabis that is a federally controlled substance, has high amounts of THC and minimal CBD. That is why medical and recreational marijuana can often only be purchased legally at state-regulated dispensaries. But hemp-derived products, which are unregulated, can be readily bought over the counter.)

The new restrictions seek to close a loophole created by the 2018 law, which said that cannabis could be legally sold as hemp if the plant itself contained no more than 0.3% of a type of THC called Delta-9.

But Delta-9 is not the only type of THC in cannabis. Cannabis contains other THC cousins, including those that can be lab-manipulated to increase potency. The 2018 law also neglected to address how much THC overall would be permitted in the final CBD product. Products with other THC compounds, in vastly varying amounts that often swamped the CBD itself, quickly flooded the market.

Sen. Mitch McConnell, R-Ky., who championed the new federal legislation last fall, said that manufacturers had been exploiting the 2018 loophole “by taking legal amounts of THC from hemp and turning it into intoxicating substances and then marketing it to children in candy-like packages and selling it at easily accessible places like gas stations, convenience stores, all across our country.”

In recent years, visits to hospital emergency departments (including veterinary clinics) related to THC-infused products have exploded. Last year, about a quarter of the 28,980 cannabis exposure cases recorded by America’s Poison Centers nationwide involved THC commonly associated with the hemp-derived cannabis market, an increase of more than 300% in four years, said Kaitlyn Brown, the organization’s clinical managing director.

To monitor the adverse effects of the products, the FDA opened safety reporting portals last year for gummies, drinks and edibles; pet owners; and health care providers. Its forthcoming lists of cannabinoids is expected to draw from those cases.

Critics of the new law say it will render illegal many CBD items that don’t have enough THC to pose any risk of intoxication.

For example: A serving of two of Charlotte’s Web’s bestselling raspberry lime Daily Care gummies, intended to “support calm, balance, and everyday stress management,” contains 25 milligrams of CBD and 0.6 milligrams of delta-9 THC from hemp, a ratio that some studies indicate is far below impairment level. A 30-day supply has 18 milligrams of THC.

But the new restrictions limit the amount of any permissible type of THC in an entire container to 0.4 milligrams.

By those standards, the product will be illegal.

Veterans’ groups have been particularly outspoken in their resistance, arguing that hemp-derived beverages are considerably less toxic than alcohol.

Nevertheless, untested, unregulated contaminants in hemp beverages, such as heavy metals, remain a health concern.