The message from the state last month was clear: Anyone selling CBD oil in Ohio now is breaking the law.

The message from some CBD sellers also was clear: Try and stop us.

Under Ohio's new medical marijuana program, only state-licensed dispensaries - which aren't open yet - can sell products made with CBD, or cannabidiol, the state declared. Cannabidiol is one of hundreds of active ingredients in cannabis plants. CBD oils and other products have become wildly popular variants of medical marijuana.

Last year, CBD sales in the United States reached $820 million and are expected to grow to $2.1 billion by 2020, according to a report by market intelligence firm, Hemp Business Journal.

But last month's advisory from the Ohio Board of Pharmacy reminding retailers of the restrictions cast a pall over CBD sales throughout the state.

Some retailers immediately pulled the products from store shelves.

Other retailers and out-of-state producers remained defiant.

E.R. Beach, owner of four Hemptations pipe stores in Cincinnati and Dayton, said he has no intention of removing CBD products that his stores have sold as supplements for seven years.

“They (law enforcement) are going to have to charge me, and if they charge me, it’ll be for possession of marijuana, and when they test the product, they’ll find that it’s not a marijuana product,” he said. “They could do that at any time.”

Beach and other retailers say their CBD products are legal because they were made from cannabis plants allowed to be grown under the 2014 federal farm bill.

QC Infusion Inc. is a Cincinnati manufacturer of CBD products such as tinctures, topicals, vaporizer oils and drinks. Nic Balzer, co-founder and chief executive officer, said similar clashes over CBD in other states have concluded hemp-derived supplements are not marijuana products

“The public should have uninhibited access to hemp-derived products no matter what state you live in. We will continue to produce these products and support our retailers and customers through this moment of confusion,” Balzer said.

Often called industrial hemp, these plants contain less than 0.3 percent of THC - the substance that gets you high - and thus, retailers say, the state doesn't have the authority to regulate those products.

“I’ve been dealing with this backlash for about a week,” Beach said about the Board of Pharmacy notice. Customers are confused about the product he sells, which he said is made from industrial hemp grown under the 2014 federal farm bill.

However, Pharmacy Board officials said the 2016 Ohio law that created the medical-marijuana program does not make a distinction between CBD from industrial hemp and other CBD extracts because they all come from the cannabis genus of flowering plants.

Ohio law defines marijuana as "all parts of a plant of the genus cannabis.'' Hemp is therefore considered marijuana under the law.

Confusion over the issue has created a conundrum for regulators, law enforcement, retailers and customers who swear by its medicinal properties.

Army veteran Joshua Benedict, 28, of Wooster said he started taking CBD oil about four or five months ago on a friend’s recommendation. He bought the oil at a local store, and he said he has found that CBD has improved his mood and attitude in dealing with post-traumatic stress disorder and other mental-health problems.

The state’s decision to make over-the-counter CBD products illegal would complicate his life, Benedict said. “If they do make it that way, that would take away something that has definitely helped me tremendously. As a veteran, it is something I’ve been able to legally use for a while now, and it’s helped me out a lot. I’m a lot more calm, I’ve noticed, and my family has noticed. I’ve noticed that my nerves aren’t as, how do I say this? Nervy.”

At least one manufacturer of CBD products from industrial hemp says the 2014 farm bill renders their goods legal, and Ohio could face a challenge to the new policy letter.

“States are welcome to make their own laws, but there is a specific federal law that should be trumping what they’re saying here,” said Lex Pelger, science director for Bluebird Botanicals, a Louisville, Colorado, manufacturer.

Texas and Alabama tried similar efforts to turn away CBD products made from industrial hemp, he said, but they backed off when the Hemp Roundtable, an industry group, challenged those decisions.

In addition, Pelger said, a new farm bill awaiting action in Congress would expand farmers' ability to grow industrial hemp. “What almost always happens is that the Hemp Roundtable, in a friendly manner, lets people know what the federal law is. … Officials want to be cautious around the laws around this tricky plant, and almost always, we don’t hear any pushback, once it’s made clear where the law is.”

The Ohio Board of Pharmacy has no immediate plans to take punitive actions against vendors of CBD products, said board spokesman Grant Miller.

But at least one local law enforcement agency said it would respond to citizen complaints about retailers who continue to sell CBD though they are not among the 56 state-licensed dispensaries permitted under Ohio's medical-marijuana plan.

The dispensaries won't go live until sometime later this year, well after last Saturday's official launch of Ohio's Medical Marijuana Control Program.

"If the sheriff’s department receives a complaint, they’ll investigate,'' said Dave Daugherty, spokesman for the Hamilton County Sheriff's Department.

While the sheriff's department doesn't have a plan or policy for enforcing restrictions on CBD sales, anyone who violates the law could be cited, Daugherty said.

The potential liability led some retailers to shy away from addressing the issue, even though they were still selling CBD products earlier this week.

A kiosk featuring CBD lotions, skin care, vaporizers, chews and other goods was doing a solid business Wednesday near the food court at Kenwood Towne Centre. Jason Friedman, who calls himself the Ohio CBD Guy, operates the kiosk, which opened only in July. He declined comment when asked about the Board of Pharmacy policy letter.

Such trepidation can be found among medical professionals and other licensed caregivers who have been put on notice by the state, said Robert Ryan, a medical marijuana advocate with the Ohio Patient Network.

"I've got members who are downright distraught,'' Ryan said. "They've been going to chiropractors and massage therapists who have received threatening letters from the state and stopped using the CBD oils that some people find to be very, very helpful. That's the real impact here.''

Still, the attempted crackdown on CBD sales may be short-lived, according to James Yagielo, an industry analyst and co-founder of HempStaff, a medical marijuana placement firm. Law enforcement doesn't have the resources to pursue violations, he said.

"Enforcement may be there for a couple of weeks or months, but the police don’t have time to go around and check every head shop or every mall kiosk to see if they have CBD products,'' he said.

Yagielo noted that last year, Indiana Attorney General Curtis Hill tried to ban CBD oil from being sold or consumed in the state. In March, Indiana's General Assembly overruled Hill and approved legislation legalizing CBD statewide.

In Ohio, Yagielo says he has his suspicions about the motivation behind the Board of Pharmacy's decision, coming as the state is about to launch the medical-marijuana program.

"It leads me to believe this was done to eliminate access to any CBD oil outside the program because it may hurt the marijuana program's bottom line as well as the state's tax revenue,'' Yagielo said. "However, at this point you can purchase hemp CBD oil online and in just about every state. I'm not aware of any state that has successfully banned it, as it's just too prevalent and too difficult to enforce.''