Health Effects & Risks of Kratom, Opioids & Other Natural Occurring Medicines | Dr. Chris McCurdy

McCurdy repeatedly hears from long‑term leaf users that ‘less is more’ — they get better mood and energy from consistently low doses. He finds this pharmacologically puzzling because typical tolerance would blunt the effect, but he speculates that the multi‑receptor activity may avoid the steep tolerance curve seen with single‑target opioids. However, when people use kratom for pain, tolerance does develop, and that drives dose escalation. Once someone steps into extract territory, the ‘less is more’ rule evaporates and the risk of full opioid dependence rises sharply. The user population seeking a high is a real but smaller group, and they are probably the ones gravitating to concentrates.

McCurdy worries about teenagers buying kratom shots from gas stations because a friend told them it’s cool. Traditional use in Southeast Asia is almost exclusively by adult male labourers; there is no tradition of children or adolescents using kratom. States that have enacted kratom regulations generally set the age at 18 or 21. The expert’s stance is that if we are serious about harm reduction, the age floor should reflect the neurobiology of addiction risk — the same reason car insurance rates drop at 25.

McCurdy explains that fresh leaves, chewed or boiled into a decoction, require the body to work hard to extract alkaloids. In the US, leaves are dried and ground, often put into capsules or powders that people toss‑and‑wash. Even that is closer to traditional use than the extracts. When a solvent pulls alkaloids out of the leaf before ingestion, the compounds are pre‑dissolved and absorbed much faster, leading to a higher peak concentration and a more abrupt effect. This changes the dynamics from a gentle, gradual onset to a rapid, sometimes overwhelming exposure. The 7‑hydroxy‑mitragynine isolate, a metabolite of the main alkaloid mitragynine that may not even exist in the plant naturally, is pure opioid agonist and has been shown in their upcoming rat study to cause respiratory depression equal to standard opioids — yet it is sold as a ‘kratom‑derived’ product. McCurdy draws the analogy to alcohol: leaf is like light beer, extracts are like spirits, and isolates are like 190‑proof Everclear. Without labeling that distinguishes these, consumers can inadvertently ingest dangerously high doses.

McCurdy explains that because kratom is not a typical opioid (it also hits serotonin and adrenergic receptors), replacing it with a pure mu‑opioid like buprenorphine or methadone only pulls one lever. The patient may still experience mood instability, lethargy, or other withdrawal‑like phenomena driven by the serotonin and noradrenergic changes. He poses the open question: are those treatments truly the right approach, or could they make things worse by introducing a harder‑to‑quit opioid? At least one human case report (2008) described a man who quit Dilaudid with kratom leaf, then after a seizure from adding modafinil, quit kratom cold turkey with only a runny nose and no cravings — suggesting that dependence intensity varies enormously with product type and individual biology.