How Do Sleeping Pills Work?

Medically approved by
Dr Earim Chaudry
Last updated
30th March 2022

In 30 seconds

Sleep is essential, but often hard to come by. For many people, using medication can help. But how do sleeping pills work? Prescription sleeping pills work on the chemicals in your brain that regulate your sleep-wake cycle. Medications that are used as OTC sleep aids cause drowsiness. And while these options can help if you have trouble sleeping, no sleeping pill is without side effects. It’s important that you stick to the lowest dosage for the shortest possible time to try to mitigate the risks.

Why sleep matters

There’s no way around it — getting sufficient sleep is vital. Sleep is how we recharge our batteries and if we don’t get enough of it, the effects are quickly made known. Research has shown consistently that sleep and the immune system are intrinsically linked, and that not getting adequate sleep can have a detrimental effect on your physical and mental health. 

That’s why the NHS recommends that we get between six and nine hours of sleep a night. 

But while we may know that we need sleep, we are not getting the sleep we need. We’re packing in impossible work days, meeting the demands of family life, and trying to keep up with our friends. Added to this, it’s often just not that easy to fall asleep (or stay asleep) when we want to. 

In this study conducted by the Sleep Foundation, about half of the participants felt sleepy at least three times per day. As the same study reports, this can affect mood, mental acuity and daily functioning. 

This 2007 study conducted in the UK showed that 37% of survey respondents had insomnia. And of that 37%, the majority of cases were persistent.

Finding strategies that support good sleeping habits is an essential part of managing our health — and, for some, sleeping pills are a part of that. 

But how do sleeping pills work? Let’s take a look.

How sleeping pills can help

The first thing to know is that not all sleeping pills work in the same way. The one thing they all have in common? They act on the brain in some manner to help you get to sleep and stay asleep.  

Sleeping pills are known by many names — sedatives, sleep aids, hypnotics and tranquillisers.

When they do what they’re supposed to, they can help you get a good night’s sleep when you need one. 

But they are not a silver bullet. It is easy to develop a dependence on them and, ironically, they may actually make your sleep worse in the long run. As a result, they should be approached with caution.

Are sleeping pills even effective?

According to this Consumer Reports survey, only about one third of the respondents who took sleeping pills reported having good or excellent sleep on the nights that they took them. 

This 2012 study concluded that they owe “half their benefit to placebo effect.” Feeling like you’re doing something about the issue can help you do something about the issue.

And this recent study showed that with the use of sleep medication, sleep problems remained the same after one or two years. 

As a result, we may need to re-think how (and if) we use sleeping pills as part of a routine.

With all that in mind, if you are struggling with chronic insomnia, finding immediate relief can be a matter of urgency. 

Types of sleeping pills and how they work

Prescription sleeping pills

  • Benzodiazepines

Used to treat insomnia, anxiety and seizures, benzodiazepines — also called benzos — work to lower brain activity and produce calming effects and drowsiness. 

This sedative effect comes from their ability to enhance your brain’s reception of a neurotransmitter called GABA — a chemical that has an important role in slowing down the activity of your central nervous system. Benzodiazepines boost what GABA is able to do in your brain, resulting in a sedative effect.

As a sleeping pill, Benzodiazepines can be beneficial for some people in the short term.

But there is a risk. Even though this is a drug that is widely prescribed, the research into its effects are still quite young. What we do know is that over time, it’s possible to become reliant on benzodiazepines and experience withdrawal symptoms if you stop taking them. If you do stop taking them, you may also experience rebound insomnia, where your previous symptoms return. 

  • Z-drugs

Zopiclone, eszopiclone, zolpidem — Z drugs get their nickname from the amount of Zs in their full names. Z drugs are also called nonbenzodiazepine hypnotics. 

They also work on your brain circuitry and the chemicals that travel within it. They, too, produce a sedative effect by slowing down your brain activity. The key difference between benzodiazepines and z-drugs is in their molecular structure.

While the risk of dependence is lower than with Benzodiazepines, Z-drugs are also not without their dangers. There is a still a risk of withdrawal and overdose, particularly in those with a history of drug abuse and/or psychiatric illness.

If you have ever experienced complex sleep behaviours, such as sleepwalking, taking z-drugs is not a good idea as they may put you more at risk. There is some evidence to suggest that z-drugs can increase the risk of stroke, falls and fractures, particularly in older adults. 

  • Antidepressants

Antidepressants work on the chemicals and circuitry in your brain to improve mood and promote feelings of calm and wellbeing. They do so by working on the behaviour of the neurotransmitters norepinephrine, dopamine, and serotonin — all of which are also important in regulating sleep cycles.

Because some antidepressants have a sedative effect, they are commonly used as a sleep aid. 

The main kinds of antidepressants that are used for this purpose are: 

  • Selective Serotonin Reuptake Inhibitors (SSRIs)
  • Tricyclic antidepressants (TCAs)
  • Trazodone

But, as this study reveals, whether they are ultimately effective or safe for this purpose is still up for debate. 

Antidepressants need to be taken with care and specifically as prescribed. As this study explains, for appropriate antidepressants to work as a sleep aid, they should be taken at a very low dosage at an appropriate time before bedtime. 

  • Barbiturates

This older form of sleeping pill has been around since the 19th century. Barbiturates act on your central nervous system to relax muscles, and slow your breathing and heart rate. As a result, they are also used to treat seizures and as a general anaesthetic. 

Barbiturates work more directly on the GABA receptors in your brain to reduce the activity of your nervous system.

They are not used as a sleeping pill as much any more because of the risk of addiction or overdose. 

  • Melatonin 

A hormone that occurs naturally in your body, melatonin is becoming increasingly popular as a supplement to promote good sleep. This hormone released by your pineal gland is instrumental in managing your sleep-wake cycle. Being exposed to light at night can disrupt your melatonin supply.  

The research is young, but melatonin supplementation may help you to get your sleep schedule back on track, particularly if it has been disrupted by work or jet lag. 

Over-the-counter melatonin is banned for usage in the United Kingdom, specifically owing to the lack of quality control of these supplements. 

But that doesn’t mean you can’t access it safely and legally. You can get it through prescription from your doctor for short term usage. 

Over-the-counter sleep aids

While it’s advisable to navigate serious sleep challenges under the guidance of your healthcare practitioner, there are over-the-counter options that can help.

These include:

 Some over-the-counter sleep medications combine valerian root with other relaxing herbal ingredients such as hops and passion flower

  • Antihistamines. Typically used to treat hay fever and allergies, antihistamines are sometimes used for their sedative effects. 

It’s not a good idea to take antihistamines for an extended period to treat sleep trouble. You can quickly develop a tolerance to them, meaning you will have to take an increased dosage to have the same effect. 

They can also cause drowsiness that could last into the next day, as well as dizziness and dry mouth. Blurred vision and trouble urinating are also possible side effects. 

What are the side effects of sleeping pills?

While they can be a godsend for some, sleeping pills are not with serious risks. 

Potential side effects include:

  • Drowsiness and dizziness. Sometimes, the sedative effects of sleeping pills can last well into the next day. This can be dangerous if you have to drive a vehicle or operate machinery. Using sleeping pills may seriously increase your risk of having a car accident
  • Withdrawal symptoms. The big irony of sleeping pills is that they make your sleep worse in the long term. When you stop taking them, you may experience poor sleep.
  • Dependence. The goal is to take sleeping pills at as lower dosage as possible for as short a period as possible. If you feel you are developing dependence on the sleeping pill you are taking, you are not alone. According to this study, for example, about 1.5 million people in Germany are dependent on sleeping pills. 
  • Elevated cancer risk. This 2012 study showed that the likelihood of developing cancer increased by 4.6 times for those using sleeping pills regularly. 
  • Parasomnia. Sleepwalking, night terrors, and sleep-related eating disorders are all examples of parasomnia. Some sleeping pills may worsen these effects
  • Memory problems. Studies have shown that people taking sleeping pills are more likely to experience memory problems and develop dementia. This is a particular concern for older adults.

What happens if you take sleeping pills and stay awake?

Staying awake after taking sleeping pills can increase your risk of developing complex sleep behaviours, like sleep walking and night terrors. It’s best to take sleeping pills only once you are ready for bed to avoid this. For some people with sleep disorders such as restless leg syndrome and sleep apnoea, it may be difficult to sleep even if you have taken sleeping pills. 

The bottom line? When it comes to the treatment of insomnia, they are not a quick-fix solutions and all medication should be taken with careful consideration.

Alternatives to sleeping pills

If you’re looking to explore other options, they do exist. 

  • Cognitive Behavioural Therapy (CBT) for insomnia. This is a structured program where you work with a medical professional that helps to identify what thoughts, feelings, and behaviours may be leading to sleep struggles. CBT is considered to be 70-80% effective, and is the first line choice for the NHS when treating insomnia.
  • Practice good sleep hygiene. That means going to bed at the same time every night (as far as possible) in a room that is quiet and dark. Device free. 
  • Daily physical activity. Getting enough exercise during the day can help you sleep better at night.
  • A warm drink before bedtime. Skip the alcohol and caffeine and opt for a cup of chamomile tea or warm milk.

Key Takeaways

Sleeping pills work by interacting with the chemical activity in your brain. There are various types, the most common of which are benzodiazepines and nonbenzodiazepines (or Z-drugs.) While they can be a useful aid in the short term, they are not without their risks. If they are helpful to you, opt for the lowest dosage for the shortest amount of time. That way, you reduce your risk of dependence and adverse health effects.

While we've ensured that everything you read on the Health Centre is medically reviewed and approved, information presented here is not intended to be a substitute for professional medical advice, diagnosis, or treatment. It should never be relied upon for specific medical advice. If you have any questions or concerns, please talk to your doctor.

Further reading

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