AMA #9: Kratom Risks, Does Infrared Sauna Work & Journaling Benefits

KEYPOINTS

• 01

  The free portion of this AMA is entirely about kratom

  Huberman devotes the publicly released first 20 minutes to one question: what are the short- and long-term effects of kratom? The infrared-sauna and journaling questions in the title are answered in the subscriber-only remainder, so these notes cover kratom only.

• 02

  Kratom is a plant-derived opioid sold over the counter

  Kratom comes from the Mitragyna speciosa tree, native to Indonesia. For at least a couple of hundred years, people have chewed its leaves for a mild stimulant effect. Today, concentrated extracts are sold as supplements, mostly in capsules and sometimes as raw powder, without a prescription in the US. Low doses feel mildly stimulating and euphoric. Higher doses act as a painkiller and sedative, which is the classic opioid profile.

• 03

  It acts mainly on the mu-opioid receptor, like morphine

  Huberman rejects the claim that kratom is fundamentally different because it hits kappa receptors while morphine and hydrocodone hit mu receptors. Kratom binds preferentially to the mu-opioid receptor, and somewhat to kappa, in places including the brainstem and the periaqueductal gray, which produces pain relief and mild euphoria. The proof: pretreating people with a mu-receptor blocker eliminates all of kratom's effects, even the mild low-dose stimulation. 'You likely like kratom because it's an opioid.'

• 04

  It does engage reward circuitry, despite claims otherwise

  Proponents say kratom doesn't trigger dopamine and so can't be addictive. Huberman says that's untrue. Mu-receptor activation indirectly recruits reinforcement circuits involving both dopamine and serotonin, the same route by which other opioids become habit-forming.

• 05

  Kratom is habit-forming and addictive at euphoric doses

  Above the low, mildly stimulating range, users clearly develop tolerance, escalating doses and withdrawal. Huberman defines addiction as continuing despite negative consequences, and more broadly as 'the progressive narrowing of the things that give you pleasure.' When he asked about kratom on social media, one camp described severe addiction, including people who needed rehab and developed other addictions.

• 06

  Some people use it to taper off stronger opioids, with conditions

  The other vocal camp credits kratom with getting them off morphine, oxycodone or hydrocodone. Physicians Huberman respects reconciled the two views. Avoid kratom if you can, but if the choice is between addiction to potent opioids and using kratom to taper off them, kratom is preferable only if the person commits to lowering the dose and eventually stopping. Anyone dependent on opioids should plan this with their physician.

• 07

  Doses aren't comparable across products

  You'll hear that 1–5 or 1–6 g per day keeps people out of the addictive range, but those grams refer to whole kratom, not its individual alkaloids. Brands differ widely in alkaloid ratios, and the alkaloids differ in how strongly they hit the opioid system, so 1 g of one product isn't equal to 1 g of another. Some users deliberately seek high-alkaloid products that hit the mu receptor hardest.

• 08

  Individual response varies enormously

  Huberman cites estimates that somewhere between 10% and 40% of people respond to opioids especially strongly and 'really like them,' though the studies are incomplete. He is the opposite. Post-surgery Vicodin makes him nauseous, and he would rather endure pain. He compares this to the 8–10% of drinkers who get an unusually large dopamine response to alcohol and face high risk of alcohol use disorder. Strong responders should never start kratom.

• 09

  Death is rare but respiratory suppression is the danger

  Kratom's potency is roughly one-sixth that of hydrocodone, and it isn't known to suppress breathing at low to moderate doses. Combined with other opioids or alcohol, or at escalating doses, it can. Huberman draws on Jack Feldman's research showing that opioids bind brainstem sites that generate the spontaneous physiological sighs that reinflate the lungs during sleep. Suppressing those sighs is a major way opioid deaths happen. The scant data suggest kratom-related deaths share this mechanism, often alongside other substances.