# Alcohol: sedative first, saboteur second

Falls you asleep faster, then fragments the second half of the night and suppresses REM.



## Takeaways

- Expect more awakenings and a higher RHR.

- Earlier is less bad than later.

- Look at your own with-vs-without numbers.



Alcohol shortens sleep onset — which is why it feels like it helps — then wears off mid-night, rebounding into lighter, fragmented sleep with suppressed REM. In 4,098 people wearing HR sensors, even low intake reduced night-time heart-rate variability ~9%; heavy intake ~40%. Galpin's clients see it as a resting-heart-rate spike.

Track drinks and the time of the last one; nights after alcohol are compared with the rest in Trends.



## Sources

- Alcohol and sleep I: effects on normal sleep (Ebrahim IO, Shapiro CM, Williams AJ, Fenwick PB, 2013)

- Acute effect of alcohol intake on cardiovascular autonomic regulation during the first hours of sleep in a large real-world sample of Finnish employees: observational study (Pietilä J, Helander E, Korhonen I, Myllymäki T, Kujala UM, Lindholm H, 2018)

- Sleep, sleepiness, and alcohol use (Roehrs T, Roth T, 2001)

---
Educational summary of published research, not medical advice. Screening scores are not diagnoses. If a score is elevated or you feel unwell, talk to a clinician.

SleepShred for iPhone: https://apps.apple.com/app/id6802040541