Does the cry it out method really work?

This has been medically reviewed by Dr. Deborah Lee of Dr Fox online Pharmacy

For some parents, the cry it out method of sleep training has worked a treat at bedtime. Whether it's their toddler or baby that's struggling to sleep through, some families have found that letting baby cry it out has allowed them to get that much needed dose of rest and sleep they needed, but is it really the best method for you?

The constant exhaustion of having a baby comes as no surprise to new parents. Having to contend with the never-ending sleepless nights and a crying baby can be tough, no matter how prepared you think you are for parenthood.

What is the cry it out method?

The cry it out method, or the extinction method of sleep training as it’s otherwise known, is a sleep training technique that involves putting your baby to bed and letting them cry until they fall to sleep. The hardest part about this method, is that it requires parents to leave baby and not fuss over them and let them exhaust themselves with crying before dropping off by themselves.

Is the cry it out method suitable for my baby?

It’s recommended that babies can start to learn sleep training at around the 4 – 6 month mark. With cry it out, it’s best to wait until your baby can go through the night without a feed, then you know that they aren’t going to be crying out because they’re hungry.

How long should I leave my baby to cry?

At first, it’s likely your baby will cry for up to an hour before dropping off, which for parents, is understandably a very difficult sound to ignore. Rest assured however, that if you choose to commit to the crying out method, your baby will eventually cry less and less and a week or so into training, they may stop crying all together.

Should I leave baby to cry it out at nap time too?

If you’re using the cry it out method at night time, it’s recommended that you use the same method at naptime too.

When to check on baby

As long as your baby is comfortable, safe, not poorly and have a clean nappy, they should be safe to leave on their own.

If you’re concerned, you can always keep a good eye on the baby monitor and if you do want to go in and check everything is okay, make it very brief.

Most parents try to stick to the training for at least two weeks before giving up, so if you’re struggling to leave your little one to cry, try to stick it out for two weeks before thinking of another method as there are so many others for parents to try. Remember, the ultimate goal is to help teach your baby to get a good night’s sleep independently which will be beneficial to both you and baby further down the line.

If you prefer to check on your baby more often, the pick up put down sleep training method might be better for you  or the Ferber method.

According to Dr. Deborah Lee, they say: "All babies cry. After birth, babies need to learn how to live outside the womb, and crying is a baby’s only means of communication. A baby has to learn the technique of how to go to sleep by himself or herself. The Cry It Out (CIO) method is a type of sleep training used to help babies learn to sleep through the night. It is also sometimes called the extinction method. Listening to your baby cry is very distressing for a parent. Although the CIO method is believed to work, it’s not the solution for every baby, says Dr. Lee.

The principle is that the parent prepares the baby for bed, soothes and cuddles them, then puts them down awake in the cot and leaves the room. They do not go back into the room until morning. They might like to use a video cam to check on the baby's wellbeing, but in general, the parent does not go back to the baby however much they cry. Some experts believe this is the way to teach a baby to self-soothe and to go off to sleep by themselves.

The exception is for night-time feeds. If you are still doing these for your baby, the feed should be brief and methodical, and the baby put down straight away afterwards and again left to go to sleep by themselves, says Dr. Lee.

Is my baby physically and developmentally ready for sleep training using the Cry It Out method?

A baby should be between 4-6 months of age for sleep training to commence. By this stage,  their Circadian rhythms will have developed so they have a natural physiological tendency to sleep through the night and be more awake during the daytime.

CIO is not appropriate for small babies who need to wake frequently to feed every 2-3 hours. It is not likely to work for toddlers who can climb out of a cot or a bed, says Dr. Lee.

Is it safe to use CIO?

On the downside

CIO is a very rigid approach - some would say unkind. It is not endorsed by the NHS.

It is not felt to be dangerous, but many parents find it stressful and unpleasant.

On the upside

In a 2020 study of 174 infants and their parents who used the CIO technique, no adverse behavioural or attachment effects were seen at 18 months of age. There are no research studies that show that the CIO method is dangerous, says Dr. Lee.

The first night is likely to be the worst. After this, the baby's sleeping pattern is likely to improve quickly as they start to understand that after their bedtime routine when they are put into their cot this means they need to go to sleep.

Other key points

Note that the CIO method should not be considered in isolation. First, your baby needs to be tired and ready for sleep at the end of the day. A 6-month-old baby should be going to sleep between 7 and 8 pm at night. If your baby is having naps, their wake window is 2-3 hours before being put to bed for the night, says Dr. Lee.

The following are all night-time sleep cues for your baby –

Some parents prefer the Ferber method which means doing all of the above, but coming back into the room after a few minutes to check and reassure the baby. Then leaving them again, this time for a minute longer than the last time. This can be effective as the baby feels reassured.

Are there any health conditions (like reflux, allergies, or feeding issues) that would make CIO unsafe or ineffective for my baby?

CIO is not recommended for babies with reflux. Acid reflux can cause discomfort and pain, and uncontrolled crying makes these symptoms worse. A GP or Paediatrician can advise on how best to treat reflux, sometimes with thickened feeds or medication, says Dr. Lee.

CIO is also not recommended for babies with allergies. Allergic reactions cause symptoms such as runny itchy eyes, a runny nose, cough, wheezing, skin rash, itching, vomiting and diarrhoea. Babies suffering from allergies of any kind should not be left to CIO. This will not help their allergies and is only likely to make them more fractious and irritable. Speak to your GP or Paediatrician on how to treat allergies in babies.

In general, a baby needs to have a well-established feeding pattern before attempting CIO. Note that a baby may still have a night-time feed at 6-8 months of age, and even if you are trying the CIO method, this does not mean you should miss this feed out. The baby will stop waking and asking to be fed when they are ready.

Is it okay to let my baby cry for extended periods, or could that be harmful?

Babies cry as this is their only method of communication. They need to be physically held in your arms during their young lives, and to gradually get used to being put down and left on their own. A period of crying is not harmful to a baby and is part of them learning to live independently, says Dr. Lee.

However, how long to let them cry, and whether extended periods of crying could be harmful, are unknown. When they cry, this raises the cortisol level. Some have theorised that extended crying could potentially affect brain growth and development. Babies need to be loved, soothed and comforted as part of their emotional development.

The NHS states that a baby can be left to cry for 10 minutes before going to check on them, soothing them and picking them up.

Caring for a baby who cries constantly is very exhausting and upsetting. There are many ways to comfort a crying baby -

How can I tell if my baby is crying from hunger vs. other needs at night?

 A baby can sleep through the night from 6-8 months old. A newborn baby feeds 2 or 3 times in the night, but by 6-8 month's they will be waking far less often, and if left alone, may well go back to sleep without the need for a feed. Now they are eating solid food, this takes longer to pass through the digestive system and keeps them feeling fuller for longer.

If they are now sleeping 5 hours or more at a time, they are unlikely to be waking at night because they are hungry. When your baby wakes in the night, wait a few minutes before going to see them. Try giving them a cuddle and putting them gently back into the cot. If they are hungry, they will let you know, often waving their arms and legs and nodding their heads. Most often, a baby just wants comfort, perhaps a nappy change or even a drink of water, and can be returned to their cot to go back to sleep, adds Dr. Lee.

Meet the author

Mummy to a little girl, Adejumoke Ilori is Commercial Content Writer for Mother&Baby. With a BA hon in Creative Writing, she has worked for digital platforms, where she has empowered women from the inside and out, by sharing real life stories based on relationships, loving yourself and mummyhood.

Meet the expert

Having worked for many years in the NHS, mostly as Lead Clinician within an integrated Community Sexual Health Service, Dr Deborah Lee now works as a health and medical writer, with an emphasis on women's health, including medical content for Dr Fox pharmacy. She has published several books and remains passionate about all aspects of medicine and sexual health. After completing her Medical Degree at University of Southampton Medical School in 1986, Dr Lee trained as a GP and after a number of years specialised in Sexual & Reproductive Health (S&RH).