From the Guidelines
To regulate your circadian rhythm, maintain consistent sleep and wake times every day, including weekends, and expose yourself to bright light in the morning, as this has been shown to be effective in regulating the body's internal clock, according to a study published in the Journal of Clinical Sleep Medicine 1. The key to regulating circadian rhythm is to reinforce the body's natural light-dark cycle, which controls the release of melatonin and other hormones that regulate sleep-wake cycle, body temperature, and other physiological processes that follow a 24-hour pattern. Some strategies to achieve this include:
- Exposing yourself to bright light in the morning by going outside for 15-30 minutes or using a light therapy box (10,000 lux) for 20-30 minutes, as recommended by a study published in the Journal of Clinical Sleep Medicine 1
- Limiting blue light exposure in the evening by using night mode on devices or wearing blue-light blocking glasses 2-3 hours before bedtime
- Exercising regularly, preferably in the morning or afternoon, but avoiding vigorous activity within 1-2 hours of sleep
- Timing meals consistently and avoiding eating large meals within 2-3 hours of bedtime
- Limiting caffeine to mornings and avoiding alcohol close to bedtime as it disrupts sleep quality
- Creating a cool (65-68°F), dark, quiet sleeping environment If needed, low-dose melatonin (0.5-3mg) taken 1-2 hours before bedtime can help reset your rhythm, but it's best used temporarily, as suggested by a study published in Clinical and Translational Medicine 1. It's also important to note that melatonin levels can be affected by factors such as light, postural changes, exercise, and certain substances, and that a washout period without NSAIDs, caffeine, and alcohol should occur prior to sample collection for melatonin, as recommended by a study published in Clinical and Translational Medicine 1. Additionally, a study published in the Journal of Clinical Sleep Medicine 1 highlights the importance of measuring melatonin in humans to assess circadian rhythms, and provides guidelines for collecting and analyzing melatonin samples. Overall, regulating circadian rhythm requires a combination of consistent sleep and wake times, strategic light exposure, and a healthy lifestyle, as supported by the evidence from studies published in the Journal of Clinical Sleep Medicine 1 and Clinical and Translational Medicine 1.
From the FDA Drug Label
Helps establish normal sleep patterns The FDA drug label does not answer the question.
From the Research
Regulating Circadian Rhythm
To regulate the circadian rhythm, several methods can be employed, including:
- Exposure to morning bright light: A study published in Sleep Medicine in 2015 2 found that morning bright-light exposure can help phase-advance human circadian rhythms.
- Melatonin supplementation: Research has shown that melatonin can help govern sleep and circadian rhythms, with studies suggesting that it can be used to treat certain insomnias and circadian rhythm sleep disorders 3, 4, 5.
- Gradually shifted sleep: The 2015 study in Sleep Medicine also found that gradually shifting sleep patterns can help regulate the circadian rhythm 2.
Light Exposure
Light exposure has been shown to impact the circadian rhythm, with:
- Blue light (460 nm) suppressing melatonin secretion in the evening 6
- Morning light exposure helping to phase-advance the circadian rhythm 2
- Even low light levels (5-10 lux) at night inducing a circadian response 6
Melatonin and the Circadian System
Melatonin plays a crucial role in the circadian system, with:
- Melatonin secretion being a reliable phase marker of the master circadian clock 4
- Exogenous melatonin being able to entrain the sleep-wake cycle in individuals with no light perception and free-running circadian rhythms 4, 5
- Melatonin agonists being developed as potential therapeutic agents for treating sleep disorders and other circadian disorders 4, 5