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New THC variety delta-8 is growing more popular, but experts urge caution

You may not know this, but there are actually several different kinds of THC — the chemical in cannabis that makes you feel high. The well known one that comes from the cannabis plant is technically called delta-9 THC.

But a new kind has emerged in the past few years — delta-8 THC.

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Instead of coming directly from the cannabis plant, delta-8 is synthesized in the lab.

"The chemical formulas are exactly the same. All that’s happened now is we've just moved the bond over one," said Kyle Boyar, a researcher at UC San Diego's Center for Medical Cannabis Research who specializes in delta-8.

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In other words, delta-8 and delta-9 have the same number and type of atoms, but one of the bonds connecting those atoms is in a different place.

"The only difference is we have a double bond that's been moved," Boyar said. "So the double bonds on one side with delta-9, then you move it over and it becomes delta-8."


So why is this new THC variety now being heavily marketed for both medical and recreational uses? Well, mainly it’s a way for cannabis producers and distributors to get around laws in states that ban THC.

To understand why, you have to start with the plant hemp. Hemp is legally defined as cannabis with no more than 0.3% of delta-9 THC. Hemp is legal, and so is its crucial ingredient CBD. And from CBD, you can synthesize delta-8 THC.

So in states that have banned cannabis that contains more than 0.3% of delta-9 THC, delta-8 falls into a legal loophole, said Jackie Bryant, a journalist who specializes in cannabis coverage.

"When they passed the Farm Bill and made CBD products legal in the United States, I don't think anybody in that process had the foresight of synthetic cannabinoids made from CBD that could have intoxicating effects," she said. "They thought, 'oh, CBD doesn't make you high. It's fine. We'll just let it go.' I don't think they fully realized is that in a lab you can take CBD, you can reverse engineer it to get THC out of it. So you can also do delta-8."

Bryant sees lots of marketing from companies selling drinks, syrups, and gummies all made with delta-8.

"A lot of people have dubbed delta-8 sort of this weed light," Boyar said. "I'd say that that's maybe valid if we're talking about inhaled. But if you're ingesting this, what happens is when you ingest delta-9 or delta-8, it goes through the liver and the first pass metabolism and so you end up getting 11-hydroxy metabolites. Those 11-hydroxy metabolites are actually much more potent."

These metabolites are chemicals created in your body when THC is metabolized. Boyar said scientists don’t know a lot about delta-8’s effects on the body yet, because so far there have been limited clinical studies.

"All these reports really are anecdotal," he said. "These are not well designed clinical trials. This is what you read about people's experiences on the Internet, this type of thing. And while that's valuable, to an extent, there's not a replacement for a clinical trial, especially if we're talking about treating a specific illness or a condition."

Delta-8 is synthesized in the lab using CBD oil and other chemicals, but Boyar said the labs that do this chemical process aren’t always well regulated.

"A lot of the people that are making this stuff, many of them are untrained and definitely don't necessarily have any business doing synthesis if they're not trained chemists," he said.

If delta-8 isn’t properly made, some of the chemical additives could end up in the product that goes out to consumers.

"You don't know what you're getting," Boyar said. "There's a lot of lack of quality control, because this is not regulated in the sense that there is no mandate saying if you put a delta-8 product on the shelf that you have to test it because it's a legal loophole, basically. And it's a brand new space, largely unregulated. People can get away with a lot. What I would recommend to consumers if they are going to purchase delta-8, make sure you have a certificate of analysis for your product from a reputable lab."

The laws differ in every state and federally, creating a huge grey area, said Meital Manzuri, a cannabis attorney.

"There's been so many contradicting statements coming out of the DEA itself that it still all needs to be sort of hashed out," she said.

Manzuri said the federal government and states are still figuring out what to do with this new delta-8 THC.

"In 18 states it is illegal," she said. "If your state has banned it, even if it's federally legal, it's illegal in those 18 states. Other states have regulated it or controlled it. Here in California, they're essentially saying that it's going to be taken into the cannabis regulatory scheme at some point and be regulated just like cannabis."

As for the future of delta-8, it’s unclear. Right now, cannabis retailers are making lots of products with delta-8 because it’s on trend and legal. But whether that will last is not yet known.

KPBS, in collaboration with NOVA PBS, is investigating the science behind delta-8 — and the legal loopholes that allow it to be sold. This reporting is made possible in part by the Corporation for Public Broadcasting, a private corporation funded by the American people.