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How Cannabis Impacts Health & the Potential Risks | Dr. Matthew Hill

In this episode, my guest is Dr. Matthew Hill, a professor of cell biology and anatomy at the Hotchkiss Brain Institute at the University of Calgary and an expert on the biology of cannabis. We discuss how cannabis affects the brain to produce its psychoactive effects (feeling “high”), including altered time perception, focus, memory, appetite, and stress. We discuss how THC vs. cannabidiol (CBD) affects the brain, the effects of different routes of cannabis administration (e.g., smoking, vaping, edibles), high-potency THC, and whether cannabis is addictive. We discuss if there is a link between cannabis use and the development of psychosis, anxiety, bipolar depression, or schizophrenia. We discuss whether CBD has clinical benefits in regulating stress, promoting sleep, and treating certain diseases. We also discuss if there are real and consistent differences in the biological effects of different cannabis strains, if cannabis impacts hormones, and the uses of cannabis for the management of pain, stress, Post-traumatic stress disorder (PTSD), anxiety, and nausea. Listeners of this episode will get an up-to-date understanding of what is currently known about how cannabis affects the brain and body, including both its potential benefits and risks. Access the full show notes for this episode at https://www.hubermanlab.com/episode/dr-matthew-hill-how-cannabis-impacts-health-the-potential-risks Thank you to our sponsors AG1: https://drinkag1.com/huberman Eight Sleep: https://www.eightsleep.com/huberman LMNT: https://drinklmnt.com/huberman BetterHelp: https://betterhelp.com/huberman InsideTracker: https://insidetracker.com/huberman Huberman Lab Social & Website Instagram: https://www.instagram.com/hubermanlab Threads: https://www.threads.net/@hubermanlab Twitter: https://twitter.com/hubermanlab Facebook: https://www.facebook.com/hubermanlab TikTok: https://www.tiktok.com/@hubermanlab LinkedIn: https://www.linkedin.com/in/andrew-huberman Website: https://www.hubermanlab.com Newsletter: https://www.hubermanlab.com/newsletter Dr. Matthew Hill Hotchkiss Brain Institute: https://hbi.ucalgary.ca/mist/team/research-chair University of Calgary academic profile: https://profiles.ucalgary.ca/matthew-hill Publications: https://scholar.google.ca/citations?user=Q494JnAAAAAJ&hl=en&oi=ao Lab website: http://www.hill-lab.ca/ X: https://x.com/canna_brain Timestamps 00:00:00 Dr. Matthew Hill 00:00:00 Sponsors: Eight Sleep, LMNT & BetterHelp 00:07:16 Cannabis, THC, Cannabidiol (CBD), Terpenes 00:12:08 Psychoactive Effects, Cannabis “High”; Time Perception 00:16:55 Cannabis & Brain, CB1 Receptor, Endocannabinoids 00:26:19 Endocannabinoids Types: Anandamide, 2-AG 00:33:46 “Munchies”, Cannabis & Appetite 00:42:17 Sponsor: AG1 00:44:06 THC & Anandamide, Pharmacology 00:52:37 THC & CB1 Receptors, Intoxication & Appetite 00:58:57 Cannabis & Focus, Memory 01:04:09 Routes of Administration, Concentration, Cannabis Research 01:15:12 Self-Regulation, Inhalation & THC, Tolerance; THC Concentrates 01:22:25 Sponsor: InsideTracker 01:23:36 Addiction & Cannabis, Cannabis Use Disorder 01:31:30 Cannabis Legalization & Use, Edibles & ER Visits 01:36:48 Oral Consumption, Edibles, Dosing & Time Course 01:41:12 Drug Testing & Cannabis, Exercise 01:46:04 Cannabis & Hormones, Gynecomastia, Sperm Quality 01:54:37 Cannabis & Pregnancy; Selling Recreational Cannabis 02:04:07 Vaping 02:07:05 Psychosis, Anxiety & Cannabis 02:17:17 Cannabis, Psychosis, Schizophrenia & Genetics 02:30:45 Cannabis Use & Schizophrenia, Manic Bipolar, THC Potency, Nicotine 02:40:37 Schizophrenia, Cannabis Legalization 02:45:06 Cannabis Strains, Indica, Sativa, Subjective Effects & Expectancy Bias 02:57:00 CBD, Pediatric Epilepsy, Adenosine 03:07:22 Entourage Effect; Placebo Effect, CBD & Doses 03:19:12 Cannabis Health Risks, Cardiovascular Risk, Schizophrenia 03:27:08 Cyclic Vomiting Syndrome & Hot Shower 03:31:30 Cannabis Benefits: Pain, Stress, Anxiety, Post-Traumatic Stress Disorder (PTSD) 03:40:18 Cannabis & Anxiety, Anandamide & Stress Response 03:45:55 Scientific Discussion, Clarification & Advancement 03:49:47 Zero-Cost Support, YouTube, Spotify & Apple Follow & Reviews, YouTube Feedback, Protocols Book, Social Media, Neural Network Newsletter #HubermanLab #Science Title Card Photo Credit: Mike Blabac - https://www.blabacphoto.com Disclaimer: https://www.hubermanlab.com/disclaimer

Andrew HubermanhostDr. Matthew Hillguest
Jul 8, 20243h 52mWatch on YouTube ↗

CHAPTERS

  1. 0:00 – 13:00

    Introduction, Origins of the Episode, and Scope of Discussion

    Huberman introduces Dr. Matthew Hill, outlines his expertise in cannabis biology, and explains that this episode arose from Hill’s public criticisms of a prior Huberman cannabis episode. They agree the conversation will not be a debate but an up-to-date, evidence-based survey on cannabis’ biology, clinical data, benefits, and harms.

  2. 13:00 – 26:10

    What Cannabis Is: THC, CBD, Minor Cannabinoids, and Terpenes

    Hill defines cannabis as a chemically complex plant containing many cannabinoids and terpenes, but emphasizes that THC is the main driver of intoxicating and psychoactive effects. CBD, while abundant in discourse, is present at low levels in typical street cannabis, has different pharmacology, and is not intoxicating.

  3. 26:10 – 35:40

    Subjective Effects: What the Cannabis ‘High’ Feels Like and How It’s Studied

    The two discuss how people typically describe being high—mild euphoria, altered perception, introspection, changes in time sense and humor—and how labs objectively measure intoxication using rating scales. Hill explains that even placebo cannabis can elicit ‘feeling high’ in experienced users, highlighting strong expectancy components.

  4. 35:40 – 1:01:00

    Endocannabinoid System 101: CB1, CB2, Anandamide, and 2-AG

    Hill explains that CB1 receptors are among the most abundant receptors in the brain, mediating THC’s effects, while CB2 are mainly on immune cells. Endocannabinoids anandamide and 2‑AG are produced postsynaptically and act retrogradely to regulate neurotransmitter release and maintain circuit homeostasis.

  5. 1:01:00 – 1:18:40

    THC vs. Endocannabinoids: Why Getting High Is Not Just ‘Boosting Anandamide’

    Hill distinguishes THC’s pharmacology from endogenous cannabinoids. THC is a high-affinity, partial agonist at CB1 that blankets all CB1 receptors regardless of context. By contrast, endocannabinoids are locally and transiently released, making their effects specific. Blocking anandamide breakdown in humans produces measurable stress and fear changes but no intoxication, showing elevating anandamide is not equivalent to THC exposure.

  6. 1:18:40 – 1:48:00

    Feeding and the Munchies: Mechanisms Behind Cannabis-Induced Eating

    They dive into how cannabinoids alter feeding circuits and reward, explaining both clinical appetite stimulation and recreational ‘munchies.’ Endocannabinoids and THC act in hypothalamus, nucleus accumbens, and taste pathways to increase motivation for food, override satiety, and enhance hedonic value, especially of sweet, high-calorie foods.

  7. 1:48:00 – 2:28:20

    THC Pharmacokinetics: Smoking, Vaping, Edibles, and Concentrates

    This chapter compares onset, duration, and blood levels of THC under different routes of administration. Hill emphasizes that with flower, users self-titrate regardless of potency but that concentrates and edibles present qualitatively different risk profiles due to higher peaks and/or long-lived metabolites.

  8. 2:28:20 – 2:48:00

    Tolerance, Addiction, and Cannabis Use Disorder

    Hill addresses whether cannabis is addictive, distinguishing cannabis use disorder from more lethal addictions like opioids or alcohol. He notes down-regulation of CB1 in heavy users, moderate tolerance, and real functional impairments in a subset of users, while also acknowledging that many daily users function similarly to nightly alcohol users.

  9. 2:48:00 – 3:09:00

    Legalization, Use Patterns, and Public Health Observations

    Using Canadian data, Hill describes how legalization has changed use patterns across age and sex, with notable increases in older adults and minimal changes in teen use. He also touches on regulatory gaps, budtender misinformation, and pediatric edible poisonings as unintended consequences.

  10. 3:09:00 – 3:23:00

    Hormones, Fertility, and Pregnancy: Mixed and Limited Evidence

    They explore claims about cannabis’ effects on testosterone, estrogen, prolactin, sperm, and pregnancy, finding the human literature mixed, often old, and generally showing modest, within-normal-range changes rather than dramatic hormone disruptions. Hill is more concerned about potential sperm quality effects and use during pregnancy, driven mostly by anti-nausea self-treatment.

  11. 3:23:00 – 4:13:00

    Psychosis, Schizophrenia, and Bipolar: Fuel on a Fire, Not a Simple Cause

    This is the most nuanced section, where Hill unpacks the relationship between cannabis and psychotic disorders. He clearly distinguishes acute drug-induced psychosis from chronic schizophrenia, arguing cannabis can unmask or worsen an underlying vulnerability but that the data do not support claims that it creates schizophrenia out of nowhere in otherwise low-risk people.

  12. 4:13:00 – 4:57:00

    Driving, Cardiovascular Risks, Lung Effects, and Cyclic Vomiting Syndrome

    They briefly touch on cannabis and driving before delving into emerging evidence for cardiovascular risk and a strange syndrome of cannabinoid hyperemesis. Hill underscores that while lethal overdoses like with opioids are virtually nonexistent, there are still significant physical risks that should influence use decisions.

  13. 4:57:00 – 5:42:00

    CBD in Detail: Epilepsy, Mechanisms, and Hype vs. Reality

    The conversation returns to CBD, where Hill distinguishes solid evidence for high-dose, pharmaceutical CBD in rare epilepsies from weak or absent evidence for over-the-counter CBD products. He details known targets like adenosine transporters and liver CYP enzymes and explains why typical consumer doses are unlikely to reach biologically active levels in the brain.

  14. 5:42:00 – 6:06:00

    Strains, Terpenes, and the Indica vs. Sativa Expectancy Problem

    Hill dismantles the popular belief that indica and sativa labels predict consistent, distinct highs. He attributes most of the reported differences to marketing-driven expectancy effects, though he acknowledges early but limited evidence that specific terpenes in specific ratios can modulate THC’s anxiogenic or analgesic properties.

  15. 6:06:00 – 6:50:00

    Stress, Anxiety, PTSD, and Endocannabinoid-Based Treatments

    Drawing on his own research, Hill discusses endocannabinoid roles in stress and anxiety, human trials elevating anandamide, and small but promising work on THC analogs for PTSD nightmares. He differentiates between treating core anxiety disorders and using cannabis as a nightly anti-nightmare tool, and is cautiously optimistic about future endocannabinoid-targeted drugs.

  16. 6:50:00

    Closing: Scientific Disagreement, Correction, and Collaboration

    They reflect on how their prior public disagreement led to this constructive, detailed discussion, modeling how scientific disputes should be handled: through data, nuance, and willingness to revise. Hill reiterates that he is neither pro- nor anti-cannabis but pro-evidence, and Huberman emphasizes his commitment to updating content as science advances.

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