Audit a URL →

Sign in Sign up free

Loading…

Weekly · Sunday Morning

Five longevity claims.
Worth your time.
Every Sunday.

Last Sunday

Rapamycin extends mouse lifespan 9–14%
NAD+ precursors reverse aging in humans
Blue-light glasses improve sleep quality
Walking 10 min after meals blunts glucose
Verdict change — caffeine half-life downgraded

5 audits·1 verdict change·0 affiliate links·Every Sunday

Joining 1,247 readers — founders, MDs, and longevity-obsessed people who fact-check their own health decisions.

Browse

Decisions Claims Content Creators

Product

Audit a URL Sunday roundup API (soon)Pricing

About

FAQ Methodology Editorial Standards Corrections Press & brand RSS feed

Legal

Terms of Service Privacy Policy DMCA

Finally, something serious in this space.
Because we actually read the papers.

© 2026 Whalespan. Independent, evidence-graded longevity.

Jet Lag, Poor Sleep, and Melatonin | Bryan Johnson Podcast — Whalespan

Content›Video›Jet Lag, Poor Sleep, and Mel…

Jet Lag, Poor Sleep, and Melatonin | Bryan Johnson Podcast

Bryan Johnson59m · 2025-07-18

Claims Made

92

Claims Supported

70

Support Rate

76%

Support rate

70 of 92 claims supported

70 supported22 partial / not

Claims from this content

68

✓Well SupportedSixty-minute naps can be rejuvenating, providing approximately 52 minutes of deep sleep.✓Well SupportedNapping for 20 minutes provides sustained benefits in alertness, concentration, and motivation.✓Well SupportedPoor sleep reduces willpower, making individuals approximately 90% more likely to choose unhealthy food options for breakfast.✓Well SupportedMelatonin can be taken at the typical destination bedtime, potentially starting before departure, and should be continued for at least the first three nights for jet lag.Well Supported

More from Bryan Johnson

Bryan Johnson's Blueprint Rapamycin Protocol

Discussion

Native comments, Twitter mentions, and Reddit threads about this content — surfaced together so the conversation isn't fragmented across platforms.

M

Share your read of this content…

Posting publicly as you · linked to your social profiles

Sort by:

AV

A. Volkovreader

4h

Bookmarking — the dossier-vs-overview split is the right call. Most of the time I want overview; sometimes I want receipts.

NP

N. Park

2d

Would love a "what would change this verdict" RSS feed. Sign me up if it exists.

✓

Getting sunlight exposure in the eyes for a few minutes upon arrival at a new location helps adapt to the new time zone.

✓Well SupportedAfter 14 days of sleeping 6 hours per night, performance is as poor as 48 hours of total sleep deprivation, with unawareness of impairment.

✓Well SupportedLight exposure is the primary regulator of circadian rhythm, with exercise, feeding, social factors, and temperature also playing roles.

✓Well SupportedJet lag occurs because rapid travel disrupts the body's natural circadian rhythm driven by the sun's light-dark cycle.

◐Partially SupportedA maximum of one international trip per quarter is a reasonable rule of thumb for trips with a 10-hour time zone change lasting around five days.

✓Well SupportedLight, eating, and exercise are the primary levers outside of medications that affect the circadian rhythm.

✓Well SupportedNon-excessive amounts of caffeine and coffee or tea can help individuals stay awake until local bedtime when traveling westward.

✕Not SupportedTraveling internationally requiring 3-4 days in a new time zone more than once a month carries risks comparable to shift work.

◐Partially SupportedCombining melatonin, light exposure, and morning/afternoon exercise can reduce jet lag symptom duration from 12 days to 2 days.

◐Partially SupportedEastbound international travel is generally worse than westbound travel because it requires speeding up the body's internal clock rather than slowing it down.

◐Partially SupportedMelatonin, including extended-release formulations, can be helpful for sleep onset and for preventing middle-of-the-night awakenings.

◐Partially SupportedThe desire for salty, fatty, or high-calorie dense junk foods can emerge after approximately 8-9 days of sleep deprivation and international travel.

✕Not SupportedIndividuals who are not natural nappers should not force themselves to nap if they are already getting sufficient sleep and feel refreshed.

◐Partially SupportedInternational travel can disrupt hormones, the microbiome, blood glucose, and satiety.

✓Well SupportedWhen traveling across multiple time zones, it takes approximately one day per time zone for the internal clock to adjust.

◐Partially SupportedTo lessen jet lag, fasting for 33 hours before and during long flights, avoiding food, caffeine, and alcohol, can be used.

✓Well SupportedSlight sleep deprivation before long flights may aid adjustment to time zone changes.

✕Not SupportedFrequent international travel with significant time zone changes can negatively impact cognition, well-being, and performance.

◐Partially SupportedTraveling internationally for 3 to 4 days can result in jet lag during the travel period, followed by an additional 3 to 4 days of recovery.

◐Partially Supported11 days of international travel with disrupted sleep and circadian rhythms led to a continuous decline in cognitive function, mood, and food choices.

◐Partially SupportedAthletes who do not recover from circadian rhythm adaptation after time zone shifts may perform worse.

◐Partially SupportedTaking a redeye flight before an important meeting can impair cognitive performance due to lack of sleep and jet lag.

◐Partially SupportedTravel schedule, including the number of time zones flipped monthly, should be a focus when assessing an individual's health.

◐Partially SupportedTraveling across multiple time zones and continuing to work while sick are ways individuals mistreat themselves.

◐Partially SupportedInternational travel, especially with significant time zone changes, increases the likelihood of getting sick.

◐Partially SupportedAdjusting travel routines with awareness of their health impact can lead to personal improvement.

✕Not SupportedTraveling on a redeye flight the night before an important meeting, without adequate sleep and while jetlagged, prevents optimal cognitive performance.

◐Partially SupportedJet lag can increase the risk of diabetes, inflammation, and cardiovascular disease.

◐Partially SupportedWearing blue light blocking glasses and turning off screens on a plane can help initiate sleep and achieve a full night's sleep.

◐Partially SupportedFrequent international travel has hidden or deferred negative health costs.

◐Partially SupportedSleep deprivation for 9-10 days combined with international travel can annihilate willpower.

✕Not SupportedConsuming stimulants like coffee or medication close to bedtime can make falling asleep more difficult and worsen jet lag.

◐Partially SupportedLimit international travel to 3 to 4 days per month or per 60 to 90 days to maintain health.

◐Partially SupportedInternational travel can cause significant damage to cognition and other bodily functions.

◐Partially SupportedTravel, including alcohol consumption, bright lights, screens, and lack of sleep, can cause significant damage that is culturally underestimated.

◐Partially SupportedBlue light hitting the back of the eyes activates the circadian rhythm and drives the suprachiasmatic nucleus.

◐Partially SupportedSleep deprivation can disrupt consistent routines and stable thought patterns, leading to an alarming change in one's self.

◐Partially SupportedOlympic athletes who do not recover from jet lag and circadian rhythm disruption can drop from gold to silver medal performance.

◐Partially SupportedLonger duration international travel that allows the body to adjust to a new time zone is preferable to multiple shorter trips.

◐Partially SupportedLight exposure, adjusting eating cycles to the destination, and morning exercise are fundamental for reducing jet lag duration.

◐Partially SupportedCryotherapy can be beneficial for multiple days after arrival by releasing epinephrine and cortisol, providing a natural morning boost that may be lacking due to jet lag.

✕Not SupportedTraveling to a different time zone negatively impacts sleep and well-being, with recovery taking up to a month.

◐Partially SupportedEvening blue light exposure can delay melatonin release by approximately 40 minutes.

◐Partially SupportedPharmacological interventions, including melatonin and extended-release melatonin, are beneficial for managing jet lag.

✕Not SupportedFrequent short international trips are akin to shift work and increase the risk of diabetes, cardiovascular disease, dementia, and death by 2-2.5 times.

◐Partially SupportedDuring a 3-4 day international trip with a significant time zone change, individuals are jetlagged and not functioning normally.

◐Partially SupportedThe gut microbiome may take 4 to 10 days to return to normal after international travel.

◐Partially SupportedA job requiring excessive work hours or frequent international travel for two years may result in a loss of 3.4 years of life.

◐Partially SupportedTraveling 3-4 days once every 90 days is a safer approach to international travel.

◐Partially SupportedA 12-hour time zone shift can be managed with specific protocols including melatonin timing, controlled daylight exposure, and exercise timing.

◐Partially SupportedTo adapt to a new time zone, avoid blue light exposure an hour before sunset and throughout the evening.

◐Partially SupportedLight exposure, eating at appropriate times, and exercising can help shorten the duration of jet lag symptoms.

◐Partially SupportedMelatonin receptor agonists and orexin receptor antagonists are non-habit forming sleep medications that may protect sleep architecture.

◐Partially SupportedDisrupting the gut's circadian cycle by traveling to different time zones can negatively impact gut function.

◐Partially SupportedInternational travel and inadequate sleep can lead to negative physiological effects that are not always subjectively apparent.

◐Partially SupportedEleven days of intentionally reduced sleep can significantly alter a person's thoughts, desires, willpower, discipline, mood, optimism, and overall personality.

◐Partially SupportedSleep disruption can lead to brain fog, mood swings, and hormonal imbalances.

◐Partially SupportedNapping during the day can help mitigate the negative effects of staying up late.

◐Partially SupportedModafinil, with a half-life of approximately 12 hours, can help maintain wakefulness by activating dopamine and is useful for travel to time zones like Europe.

◐Partially SupportedMedapanil, with a half-life of approximately 12 hours, is recommended for situations requiring prolonged wakefulness, such as travel to Europe.

◐Partially SupportedTo maintain one's original time zone while traveling internationally for 3-4 days, avoid light exposure, eat on schedule, sleep on schedule, and exercise on schedule.

✕Not SupportedInternational travel can lead to cardiovascular disease, dementia, and early death.

✕Not SupportedTraveling internationally once per month for 3 to 4 days is considered 'red zone territory' and involves accepting damage and recovery time.

◐Partially SupportedFrequent international travel without accounting for circadian rhythm adaptation may reduce cognitive performance.