NOEL KING, HOST:
All right. We know that opioids like morphine and heroin are very dangerous. But in some parts of this country, you can buy a supplement that acts like an opioid out of a vending machine. It's an herbal product from Asia called kratom. Lesley McClurg of KQED wondered whether it's a helpful herb or a dangerous drug.
LESLEY MCCLURG, BYLINE: A yellow sandwich board on a San Francisco sidewalk advertises pain relief, energy, relaxation and mood enhancement.
LINDA KLINE: We're selling a product called kray-tum (ph), or some people will call it krae-tum (ph).
MCCLURG: That's K-R-A-T-O-M, a Southeast Asian herb that's usually sold as a green powder in capsules or tea. Linda Kline opens the door to a tiny, immaculate shop called Bumble Bee Botanicals. The 33-year-old shop owner has neatly arranged kratom in a huge mason jars.
KLINE: So this is one of our personal favorites. It's called the Green Malay.
MCCLURG: Linda says the drug turned around her mental health.
KLINE: I went from feeling desperate and hopeless to finding an alternative where I had full control over how I felt.
MCCLURG: Anxiety used to paralyze her.
KLINE: I would have panic attacks a lot.
MCCLURG: A friend suggested kratom. Linda found it at a smoke shop. Her anxiety vanished. The new habit cost about $6 a day.
KLINE: It almost feels like you're having just a little glass of wine. It's really relaxing.
MCCLURG: But there's a dark side. In 2016, the Drug Enforcement Administration threatened to ban kratom. It's currently listed as a drug of concern. The Food and Drug Administration has recalled dozens of products tainted with salmonella and warns consumers not to use it because of the risk of addiction. And people can overdose. Mateo Martinez is still mourning the loss of his brother.
MATEO MARTINEZ: My brother believed the marketing of kratom - that it was a natural herbal supplement that could provide you with the same benefits of an opioid without the risks.
MCCLURG: Marco Martinez struggled with an opioid addiction in high school. Mateo describes him as creative, charming...
MARTINEZ: A regular young kid that liked playing video games and watching cartoons and anime.
MCCLURG: Marco got hooked on painkillers after his dentist pulled his wisdom teeth.
MARTINEZ: He was using them in a way that wasn't just for treating pain.
MCCLURG: Eventually, Marco wanted to kick his addiction. Testimonials on YouTube promised kratom was his way out.
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UNIDENTIFIED PERSON #1: I'm not using narcotics anymore.
UNIDENTIFIED PERSON #2: I have a job. I'm part of my daughter's life again. I'm so grateful for kratom.
UNIDENTIFIED PERSON #3: It was life-changing.
MCCLURG: Soon, Marco was taking kratom multiple times a day. Then the 19-year-old landed in the emergency room over and over.
MARTINEZ: Hyperventilating, breathing like - (imitating labored breathing).
MCCLURG: Doctors were unable to explain these episodes.
MARTINEZ: His body wasn't fully processing all of the kratom or its byproducts, and it built up until he stopped breathing.
MCCLURG: The toxicology report showed high levels of the psychoactive ingredient in kratom. And it was listed on his death certificate.
MARTINEZ: That they attributed was the cause of death.
MCCLURG: In a recent 18-month period, the Centers for Disease Control reported 90 kratom overdoses - although most of these deaths involved a combination of substances.
MICHAEL WHITE: The data to support either the benefits or the harms for kratom is really, really poor.
MCCLURG: Michael White is a pharmacist at the University of Connecticut. He says animal studies suggest kratom could be an effective pain reliever. But...
WHITE: The human data is in its infancy.
MCCLURG: Dr. Scott Steiger runs the Opiate Outpatient Treatment Program (ph) at San Francisco General.
SCOTT STEIGER: I have seen that people who use kratom end up having a very hard time stopping the use of it.
MCCLURG: He says kratom is addictive. It also may cause seizures, heart issues and liver damage. Users say they experience withdrawal symptoms like...
STEIGER: Nausea, sweats, aches and pains, loose stool, tearing.
MCCLURG: If someone comes to you and says - should I use this? - or I am using this, how do you counsel them?
STEIGER: I tell them, you know, I just don't know enough on the basis of science to tell them whether it's a great idea or not.
MCCLURG: Steiger says a lot more research is needed, not only to weigh the risks and benefits but also to regulate the substance appropriately.
For NPR News, I'm Lesley McClurg.
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