Behind Social Jet Lag: How Alcohol Throws Your Internal Clock Off Track July 8, 2025 It’s Friday night, you’re out with mates, and a few drinks in, you’re feeling relaxed and ready for the weekend. But have you ever noticed how sluggish and moody you feel the next morning—or even on Monday? That’s not just a hangover. What you’re experiencing could be a case of “social jet lag” driven by alcohol’s powerful impact on your body clock. What Is Social Jet Lag? Social jet lag refers to the mismatch between your body’s internal clock—your circadian rhythm—and your actual sleep schedule, especially on weekends.1 When you stay up late drinking and sleep in the next morning, your circadian rhythm gets thrown off, similar to the way flying across time zones affects your body. And when alcohol is in the mix, it gets even messier. Alcohol and Your Sleep Cycle How much you drink—and when—plays a huge role in how well you sleep. Once alcohol enters your bloodstream, your liver works to break it down at a rate of about one drink per hour.2 If you go to bed with alcohol still in your system, your body’s natural sleep cycle is disrupted. You may fall asleep faster, but the quality of sleep takes a hit.2 Even low amounts of alcohol (less than two drinks for men, one for women) can reduce sleep quality by 9%.2 Moderate amounts cut sleep quality by 24%, and heavy drinking can slash it by nearly 40%.2 That’s because alcohol initially increases deep sleep, but suppresses REM—the stage critical for memory, learning, and emotional regulation. Later in the night, as your body metabolises the alcohol, you experience more light, fragmented sleep.2 The Bigger Disruption: Your Body Clock Beyond just sleep stages, alcohol throws your entire circadian rhythm out of sync.3 The master biological clock in your brain relies on cues like daylight and darkness to regulate everything from sleep and mood to immunity and digestion.3 Alcohol dulls your brain’s sensitivity to these cues, leading to irregular melatonin production and confusion in your sleep-wake cycle.3 Regular weekend drinking can also interfere with melatonin production (cutting it by up to 20%) and increase adenosine levels, making you drowsy at unnatural times.3 The result? You’re sleepy when you should be alert and wired when you should be resting. Widespread Effects of Disrupted Rhythms When your body clock is thrown off, it doesn’t just affect sleep. Your liver, gut, and immune system all operate under circadian control.3 Alcohol-related rhythm disruption has been linked to poor liver function, leaky gut, and longer-term issues like insomnia and fatigue.3 These effects linger even after the drinking stops—though with abstinence, circadian rhythms typically resettle within two to three weeks (melatonin may take longer).4 This Alcohol Awareness Week, Pay Attention to the Clock More than 2.3 billion people globally drink alcohol, and millions struggle with alcohol-related disorders.4 While a few drinks on the weekend might feel harmless, their impact on your internal rhythms adds up. If you’re frequently tired, irritable, or struggling to sleep well—even without a hangover—it might be time to reassess your drinking habits. Your sleep and health are worth protecting. If alcohol is affecting your sleep or mood, speak to your doctor or reach out to us at Sove CPAP Clinic to speak to one of our Respiratory and Sleep physicians. Small changes—like stopping alcohol at least four hours before bed—can make a big difference.2 Let this Alcohol Awareness Week be the start of a more rested, balanced you. How Sove CPAP Clinic Can Help Founded in 2008, Sove CPAP Clinic has grown to become a leading provider of respiratory and sleep services and products in Australia, with over 60 clinics nationwide. Our comprehensive clinical team includes Respiratory & Sleep Specialists, Sleep Technologists, and CPAP Consultants, ensuring that you receive comprehensive and personalised care. All medical procedures, including sleep studies and lung function testing, are bulk billed to all Australians, with minimal wait time. If you would like to speak to a Respiratory & Sleep Physician, book a bulk-billed sleep study, or seek advice for your sleep apnea, you can reach us at 1300 76 29 39 or info@thecpapclinic.com.au. ALWAYS FOLLOW THE DIRECTIONS FOR USE. CPAP is used for Obstructive Sleep Apnea treatment. When considering whether a sleep study or CPAP is right for you, speak to your doctor. Medicare criteria and T&Cs apply. References Caliandro, Rocco, et al. “Social Jetlag and Related Risks for Human Health: A Timely Review.” Nutrients, vol. 13, no. 12, 18 Dec. 2021, p. 4543, www.ncbi.nlm.nih.gov/pmc/articles/PMC8707256/, https://doi.org/10.3390/nu13124543. Bryan, Lucy, and Abhinav Singh. “Alcohol and Sleep.” Sleep Foundation, 4 Sept. 2020, www.sleepfoundation.org/nutrition/alcohol-and-sleep. “Alcohol and Sleep: What You Need to Know.” Psychology Today, 2018, www.psychologytoday.com/au/blog/sleep-newzzz/201801/alcohol-and-sleep-what-you-need-know. Meyrel, Manon, et al. “Alterations in Circadian Rhythms Following Alcohol Use: A Systematic Review.” Progress in Neuro-Psychopharmacology and Biological Psychiatry, vol. 99, Apr. 2020, p. 109831, https://doi.org/10.1016/j.pnpbp.2019.109831. Accessed 7 Sept. 2020.
