From the Research
For shift workers with circadian rhythm disorders, the optimal dosage of melatonin is 3 mg taken 30 minutes before the intended sleep time, as it has been shown to significantly improve sleep onset latency and sleep efficiency 1.
Key Considerations
- The timing of melatonin intake is crucial, and it should be taken after the night shift when the individual plans to sleep during daytime hours.
- Lower doses (1-3 mg) are often sufficient and may cause fewer side effects like grogginess, while some individuals might need up to 5 mg for effectiveness.
- Melatonin works by signaling to the body that it's time to sleep, helping to reset the circadian rhythm that becomes disrupted during shift work.
Additional Recommendations
- Shift workers should maintain a consistent sleep schedule even on days off to help regulate their circadian rhythm.
- Using blackout curtains to create darkness during daytime sleep and avoiding caffeine and bright screens before bedtime can also help improve sleep quality.
- If melatonin causes morning grogginess, trying a lower dose or a different timing might help.
- Individuals should consult with their healthcare provider before starting melatonin, especially if they have existing health conditions or take other medications.
Evidence Summary
- A randomized, double-blind, placebo-controlled crossover field study found that 3 mg of melatonin taken 30 minutes before nighttime sleep significantly improved sleep onset latency and sleep efficiency in shift workers with difficulty falling asleep 1.
- A systematic review and meta-analysis found that melatonin (1-10 mg) taken after the night shift may increase sleep length during daytime sleep and nighttime sleep, but the quality of evidence was low 2.
- Other studies have shown that melatonin can help regulate the circadian rhythm and improve sleep quality in shift workers, but the optimal dosage and timing may vary depending on individual factors 3, 4.