CBD has exploded in popularity over the last year, with countless numbers of people trying it as a sleep aid or relief for pain and anxiety. One concern is, there's been no guidance on how to use CBD, or cannabidiol, safely.

That's one reason why on Tuesday, the Arthritis Foundation released guidelines for people who want to try CBD — the first such guidance on using the cannabis-derived ingredient from any major patient advocacy group.

The recommendations are an attempt to provide some kind of clarity for CBD usage, despite a lack of scientific evidence proving that it works to treat pain.

"It was important to acknowledge the public's interest, and put out some guidelines on the state of the science," said Kevin Boehnke, a research investigator who works in anesthesiology at the University of Michigan. Boehnke helped develop and write the guidelines for the Arthritis Foundation.

The group makes it clear that patients should not abandon arthritis medications already prescribed by doctors.

"The guidelines are not saying, 'You should try this.' They're saying, 'If you want to try, here's how you should do it,'" Boehnke said.

CBD products became widely available after Congress passed the Farm Bill in 2018, which removed hemp from the controlled substance list. By itself, CBD does not cause a “high.” (Marijuana's psychoactive effects instead come from a different compound, THC, or tetrahydrocannabinol.)

Since then, the task of regulating CBD products has fallen on the Food and Drug Administration, but so far the agency has not done so.

The result has been a public frenzy around CBD products, which are marketed and sold with a variety of health claims, including relief for pain, insomnia and stress. Those assertions caught the attention of those suffering from arthritis, a condition for which there is no cure.

The Arthritis Foundation surveyed more than 2,600 patients, finding that nearly 80 percent are either currently using CBD, have used it, or are considering it for their joint pain.

The group admits any evidence showing CBD might be an effective pain reliever is anecdotal, and encourages more scientific research needed to prove safety and efficacy.

Until those studies are completed, the Foundation suggests people who want to try CBD start slowly with the lowest dose, and track symptoms over time.

If CBD alone does not help joint pain, some patients may want to try THC. As long as patients live in states where THC is legal, the Arthritis Foundation again suggests starting with the lowest dose.

For both CBD and THC products, the group urges patients to work with a physician to find products from reputable retailers who use independent, third-party testing.

But finding such a retailer can be difficult, acknowledged Boehnke. With a lack of government oversight, the onus is on the consumer.

"People have to do their homework. It's a Wild West situation. Studies have shown the amount of CBD inside a product doesn't always match up with what's on the label," Boehnke told NBC News.

Outside experts called any guidelines on a substance for which there is no regulatory guidance “irresponsible.”

"Before CBD supplements are recommended, we need to have a marketplace where the label actually reflects what’s inside them, and we know that the dose is safe,” said Dr. Pieter Cohen, who studies drug ingredients in the marketplace at the Harvard Medical School and the Cambridge Health Alliance. “We don’t have any of that in place right now.”

For patients who want to try CBD products anyway, the Arthritis Foundation recommends the kind of CBD oil found in sprays or liquid drops that patients hold under their tongue for at least one minute. This method allows the product to go directly into the bloodstream.

Don't vape CBD

The group does not recommend CBD edibles or lotions, because less is known about how the ingredient acts when it's digested or absorbed through the skin.

Also, the Foundation makes it clear CBD should not be vaped, especially as health officials nationwide continue to investigate vaping-linked respiratory illnesses that have killed eight people and hospitalized hundreds.

The group also said it’s possible CBD may interact with some medications, such as naproxen (sold over the counter as Aleve), corticosteroids and some anti-depressants.

There is only one CBD drug for which there has been extensive research, and has been approved by the FDA. That is Epidiolex, which treats two rare and severe forms of epilepsy that affect children.

Dr. Eric Westerman, a rheumatologist in Denver, estimates 90 percent of his patients ask him about CBD. He did not help develop the guidelines, but does sell a topical CBD product for pain relief.

Westerman told NBC News his group is doing extensive testing on the product, and agrees that oversight is needed to ensure safety and efficacy for all CBD products.

“I’m not concerned not so much about CBD,” said Westerman. “I'm way more concerned about potential contaminants.”

An estimated 54 million Americans have been diagnosed with arthritis.

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