Drugs & Substances
- Drinking Alcohol in the evening is known to reduce the amount of your REM sleep.
- You should stop drinking coffee around 8-10 hours before your bedtime to avoid affecting your sleep, see the The 10-3-2-1-0 Rule
Body functions
- Melatonin does not seem to have an effect on sleep quality or length
Optimal Amount of Sleep
According to the National Sleep Foundation, these are the optimal amount of sleep you should get based on your age:
- Teenagers (14-17): 8-10 hours sleep
- Adults (18-64): 7-9 hours sleep
- Older adults (65+): 7-8 hours sleep