Substances that
Affect Sleep

Throughout the course of a day, we may use several different substances that affect our sleep. We may even use some early in the afternoon, yet they have lingering effects that make it hard to fall – or stay – asleep.




One of the major stimulants many of us use every day is caffeine, which works by slowing the actions of the hormones in the brain that make us tired, especially adenosine. It is the world’s most popular psychoactive drug and is present in popular food and drinks such as coffee,tea, soda and chocolate. It can also be taken in tablet form. While caffeine wears off in a couple of hours, it can take more than five hours for caffeine levels in your body to halve and considerably longer for it to leave your system entirely.

Energy Drinks

Like coffee, most energy drinks contain caffeine in addition to a whole laundry list of other stimulants such as taurine, guarana and ginseng. They also contain sugar, which can affect sleep patterns quite considerably.


Nicotine is another often overlooked substance that affects sleep. Tobacco is a stimulant even though it can actually make you drowsy during the day. As a result, smokers often have a difficult time falling asleep, with increased arousals throughout the night. A new symptom has been described in established smokers called nocturnal sleep-disturbing nicotine craving where approximately 20% of smokers wake up one or more times during the night and have to smoke before they can return to sleep.




Alcohol is often used by people to help them fall asleep. Although it can help induce sleep, alcohol provides a transient sedative effect, causing people to wake during the night and then have a hard time getting back to sleep again. As a result, the recuperative nature of sleep is reduced and the percentage of REM sleep increases.

Alcohol also increases the occurrence of other sleep disorders such as snoring, sleep apnea, periodic limb movements and sleepwalking. All of these present varying health risks.

Prescription Drugs

Some prescription drugs contain stimulants that work on the brain’s receptors. These include amphetamines that are often used in drugs that treat ADHD and sleep disorders, as well as certain antidepressants such as fluoxetine (branded as Prozac or Sarafem). Consequently, a side effect of these often popular drugs is sleep disruption.

Branded Prozac and Sarafem are trademarked by Eli Lilly and Company.