Just weeks prior to his death, Brandon Clarke was arrested for possession of kratom.

The NBA player allegedly had nearly half a pound of it.

But what exactly is it? According to Health and Human Services Secretary Robert F. Kennedy Jr., who’s launching a federal crackdown on 7-OH — the synthetic byproduct of the kratom plant — it’s dangerous.

Available widely in gas stations and convenience stores across the US, the opioid-like substance is drawing scrutiny for its potent effects and high risk of abuse.

Kratom is what?

Kratom is an herbal extract made from the leaves of a Southeast Asian tree called Mitragyna. Users chew the leaves, brew them into tea or take it in powder, capsule or extract form, according to the Mayo Clinic. 

“Kratom affects the brain like a stimulant at low doses — boosting energy, focus and mood,” Dr. Joseph Volpicelli, a clinical adviser for Oar Health, told The Post. “Similar to a sedative at higher doses, it also provides pain relief and euphoria.”

Its popularity has soared in the US in recent years, with many turning to it as a so-called natural fix for pain, anxiety, depression and even to kick opioid addiction.

Kratom is legal for adult use at the federal level, though the FDA hasn’t approved it for any medical purpose. Several states — including Alabama, Rhode Island and Wisconsin — have banned its sale and possession outright.

Is kratom dangerous?

“‘Natural’ doesn’t mean safe,” Volpicelli warned.

Kratom can cause nausea, vomiting, constipation, drowsiness, dry mouth, itching and loss of appetite — with heavier use sometimes leading to seizures, hallucinations, liver damage and even death, according to the Drug Enforcement Administration.

National poison control centers documented 1,807 calls about kratom exposures between 2011 and 2017, a number that’s “only been increasing since then,” Dr. Michael Greco, an emergency medicine physician, told The Post this week.

A Washington Post analysis found kratom listed in at least 4,100 deaths from 2020 to 2022. Last year, the Tampa Bay Times uncovered more than 580 kratom-related deaths in Florida alone since 2013.

“It can be especially risky when mixed with other substances or used in high doses, like we have seen in the drink ‘Feel Free,’” Volpicelli noted.

How addictive is kratom?

Though some people say that it has helped them wean off or manage other dependencies, including to opioids and alcohol, kratom can be highly addictive in its own right — especially for people who already struggle with addiction.

“In the past two years, I have noticed an increased number of people coming to my clinic for the treatment of kratom addiction,” Volpicelli said.

“These people find it difficult to control their use of kratom and experience opioid-like withdrawal symptoms when they stop.”

That’s because kratom’s active ingredients — mitragynine and 7-hydroxymitragynine (7-OH) — bind to the same brain receptors as morphine and alcohol, triggering a rush of dopamine, the body’s “feel good hormone.”

“That creates a dangerous, addictive cycle where kratom use increases the craving for more use,” Volpicelli said.

Over time, users can build a tolerance and face withdrawal symptoms, such as insomnia, nausea, muscle pain, irritability and even involuntary jerky movements, according to American Addiction Centers.

What is 7-OH — and is it more dangerous?

While 7-OH can be found naturally in kratom in small amounts, manufacturers have figured out how to supercharge it — boosting its concentrations in capsules, powders, liquids and edibles.

Some of these souped-up products contain 109% to 509% more 7-OH than what’s naturally in the plant. Experts warn that means they will have stronger effects — and a greater risk for addiction and harm.

“7-OH is an opioid that can be more potent than morphine,” FDA Commissioner Marty Makary said in a statement.

The synthetic byproduct isn’t legal in dietary supplements or food products. There are no approved drugs containing it, and no legal basis for companies to claim it helps with pain or anxiety, according to the agency.

“Consumers who use 7-OH products are exposing themselves to products that have not been proven safe or effective for any use,” the FDA warned.

What is the federal government doing about 7-OH?

The FDA is pushing to add the opioid-like ingredient to the federal controlled substances list.

The agency wants 7-OH classified as Schedule I, a category reserved for illicit drugs with no medical use and a high potential for abuse — alongside heroin and LSD.

In a recent report, the FDA said it’s still concerned about kratom in general, but 7-OH’s heightened risks demand urgent action.

“We’re not targeting the kratom leaf or ground-up kratom,” said Makary. “We are targeting a concentrated synthetic byproduct that is an opioid.”

Next up, the DEA will review 7-OH and decide whether to officially label it an illicit drug. A national ban wouldn’t kick in until new rules are drafted and finalized.

“Vape stores are popping up in every neighborhood in America, and many are selling addictive products like concentrated 7-OH,” Makary warned. “After the last wave of the opioid epidemic, we cannot get caught flat-footed again.”

The American Kratom Association, which has fought restrictions on the plant for years, praised the FDA’s crackdown on 7-OH.

“These 7-OH products are not kratom. They are chemically altered substances that carry potent opioid-like effects and pose an imminent threat to consumers,” Mac Haddow, senior fellow on public policy at AKA, said in a statement.

“This move sends a clear and long-overdue message: the safety of the American public comes first.”