This week’s clearest protocol signal is the Huberman Lab Essentials re-release of Dr. Susanna Søberg’s minimum effective dose for cold and heat. It pairs with a direct correction on melatonin dosing from sleep specialist Dr. Michael Breus on The Neuro Experience. Both items shift how people dose temperature stress and a widely used hormone supplement.
Søberg Principle: 11 Minutes of Cold and 57 Minutes of Sauna Weekly
Source: Huberman Lab Essentials — Cold & Heat Exposure for Metabolic Health | Dr. Susanna Søberg — 5 Nov 2026 — hubermanlab.com episode
Søberg’s research on winter swimmers identified a minimum effective dose of roughly 11 total minutes of cold-water immersion per week, split into 2–3 sessions of 1–2 minutes each in water cold enough to be uncomfortable. Paired with that is approximately 57 total minutes of sauna per week in 10–15 minute sessions at about 80°C. The key sequencing rule—the Søberg Principle—is to end the contrast session on cold. Finishing cold forces the body to reheat itself for hours afterward, sustaining brown-fat activation, thermogenesis, and elevated metabolic rate. The protocol improved insulin sensitivity and glucose clearance in the studied groups while also lowering inflammatory markers. It is intended for metabolically healthy or mildly insulin-resistant adults who can tolerate brief cold exposure; it is not a substitute for exercise or nutrition. Overdoing the cold beyond the minimum can increase cardiovascular strain without additional benefit.
Why it matters: Most people treat cold exposure as an endurance test. The data show a low weekly volume is enough to shift insulin sensitivity and keep brown fat active for hours after the session. Ending on cold is the lever that extends the effect; ending on heat cancels it. For anyone tracking fasting glucose, HbA1c, or body composition, this is a concrete temperature protocol with a measurable endpoint.
Horizon: NOW
Evidence grade: cohort / mechanistic
Read or watch: FULL
Caveat: Not for people with uncontrolled hypertension, Raynaud’s, or recent cardiovascular events. Start shorter than 1–2 minutes if unadapted. No commercial stack required.
Tag: Cardio-Metabolic | Training | Longevity
Melatonin: Start at 0.5 mg, Not 5 mg
Source: The Neuro Experience — Sleep Expert: This Changes Everything Doctors Know About Your Sleep | Dr. Michael Breus — 27 Oct 2026 — episode page
Breus states that store-bought melatonin is routinely dosed several times higher than the research supports. The physiologically relevant range for adults is 0.5–1.5 mg; he recommends starting at 0.5 mg (or 0.3 mg if available) 30–90 minutes before bed. Higher doses (3–10 mg common in gummies) can blunt the body’s own production, increase next-day grogginess, and produce vivid dreams or nightmares. Melatonin interacts with oral contraceptives and SSRIs, altering their effectiveness. He advises against routine use in children under 18 except in specific autism-spectrum cases under medical supervision. For middle-of-the-night awakenings (driven by the normal core-temperature rise between 1–3 a.m.), the protocol is: stay in bed, do not check the clock or get up to urinate if avoidable, and use 4-7-8 breathing until heart rate drops. He also notes that a neck circumference over 17.5 inches carries an 83% probability of obstructive sleep apnea and recommends at-home or lab sleep studies when snoring or daytime fatigue is present.
Why it matters: Millions take 5–10 mg melatonin nightly. The correction is that lower doses more closely match endogenous production and avoid the side-effect profile of pharmacological doses. Combined with the 3 a.m. temperature explanation, it replaces “take more” with a specific behavioral and dosing rule.
Horizon: NOW
Evidence grade: clinic protocol / mechanistic
Read or watch: SKIM
Caveat: Not a treatment for clinical insomnia or untreated sleep apnea. Interacts with hormonal contraception and certain antidepressants. Children should not use it without specialist guidance.
Tag: Sleep | Supplements | Hormones
Watch next
Upcoming Huberman guest episodes and any new Søberg or brown-fat follow-up papers. Brecka’s next hormone-panel episodes if they include specific DUTCH or free-hormone ranges.