Written by: Jenn Schoen, Certified Pediatric Sleep Consultant

Sleep training is one of the most widely discussed—and often misunderstood—topics in early parenting. With so many opinions and conflicting advice, it’s natural to wonder whether sleep training actually works. Here’s the good news: decades of research and real-world experience show that sleep training can significantly improve sleep for both babies and parents when it’s done in a developmentally appropriate and consistent way.

This article breaks down why sleep training works, what the research says, what results to expect, and how to choose an approach that fits your family’s needs.

What Exactly Is Sleep Training?

Sleep training simply means helping your baby learn to fall asleep—and fall back asleep—on their own without needing the usual lineup of sleep props. The goal is not to leave your baby hanging. It’s to give them the skills to settle in their crib under consistent conditions so nights feel calmer for everyone.

Key things to know about sleep training:

• Not for newborns: Babies under 4 months aren’t developmentally ready for sleep training. In those early weeks, your job is gentle habit-building, feeding, and helping their little internal clock sort itself out (e.g. resolving day-night confusion).
• Most families start between 4-6 months: Around this time, sleep cycles mature and babies can safely practice falling asleep independently through sleep training methods. 
• It’s a learning process: Depending on the sleep training method you select, it can take up to 2 weeks (or longer) to successfully sleep train your child. Babies learn best with repetition, so staying consistent throughout the sleep training process is critical.
  
  

And just to set expectations: The goal of sleep training is not zero night wakings—it’s reducing unnecessary ones. Caregivers should always respond to wakings related to hunger, illness, discomfort, or true distress.

Does Sleep Training Work? The Short Answer: Yes

Most families that sleep train see meaningful improvements in their baby’s sleep within 3–14 days, depending on the sleep training method they choose and how consistently the plan is followed. And the evidence backs this up.

A large body of research, spanning more than two decades, shows that sleep training is both effective and developmentally safe for infants and toddlers. Studies consistently report that sleep training:

• Reduces the number of night wakings
• Shortens the amount of time it takes for babies to fall asleep
• Improves the predictability and quality of daytime naps
• Increases total nighttime sleep
• Enhances parental sleep, mood, and overall mental health
  
  

Sleep Training Dramatically Improves Night Wakings and Sleep Onset

This comprehensive review by Mindell et al. (2006) analyzed 52 clinical trials evaluating behavioral sleep interventions for infants and young children. It remains one of the most frequently cited evidence summaries on sleep training.

Key Findings:

• 94% of infants showed significant sleep improvements within two weeks.
• Babies fell asleep faster and experienced fewer night wakings.
• Parents reported more consistent sleep patterns following the intervention.
  
  

Study Conclusion: Sleep training is highly effective in improving infant sleep, and the benefits are sustained over time—not just short-term gains.

Sleep Training Reduces Maternal Depression and Improves Family Well-Being

A randomized controlled trial by Hiscock et al. (2007) examining the effect of structured sleep training on both infant sleep and parent well-being.

Key Findings:

• Infants who received sleep training had significant reductions in sleep problems.
• Mothers experienced lower rates of depression and improved mental health.
• Families reported better overall functioning and lower stress levels.
  
  

Study Conclusion: Sleep training benefits both infants and caregivers, improving not only sleep but also parental mental health and family well-being.

Sleep Training Is Safe and Supports Healthy Attachment Long-Term

A follow-up study by Price et al. (2012) tracking families five years after they participated in infant sleep training, evaluating long-term emotional, behavioral, and attachment outcomes.

Key Findings:

• No differences in emotional development, behavior, or parent–child attachment between sleep-trained children and their peers.
• Children who underwent sleep training were equally securely attached and emotionally well-regulated.
  
  

Study Conclusion: Sleep training is a safe, developmentally appropriate intervention with no long-term negative effects on emotional health or attachment.

The Takeaway 

While sleep training isn’t a one-size-fits-all solution, a consistent, evidence-based and developmentally appropriate method is highly effective for most families—and the benefits often extend beyond sleep to parental well-being and overall family harmony.

Why Sleep Training Works

Sleep training succeeds because it aligns with how infant sleep cycles are naturally structured. Babies, like adults, transition between light and deep sleep and naturally rouse throughout the night. Without independent sleep skills, babies may fully wake and cry for help to recreate the conditions in which they fell asleep.

Sleep training works by:

• Removing external sleep props
• Reducing unnecessary night wakings
• Allowing babies to practice self-settling
• Supporting consistent routines
• Helping babies connect sleep cycles more smoothly
  
  

As independent skills develop, bedtime and night wakings become less fragmented, and sleep naturally improves.

Is Sleep Training Safe?

Yes. Decades of high-quality research consistently shows that sleep training is safe, developmentally appropriate, and does not harm attachment, emotional development, or behavior.

In fact, when done using evidence-based methods, sleep training often supports healthier sleep, stronger emotional regulation, and more positive parent-child interactions.

How Long Does It Take to Work?

The timeline for sleep training varies widely depending on the method you choose, your baby’s temperament, and how consistently the plan is followed. While some approaches produce results in just a few nights, others take more time because they focus on gradual, low-stress transitions.

Here’s a breakdown of typical sleep training duration by method type:

• Gentle approaches: These methods prioritize parental presence and slow, supportive changes. Jenn shares, “Because these methods employ a high degree of parental involvement, it takes longer for babies to develop their independent sleep skills through the process. It’s most common to see gradual improvement unfold over a two week period rather than a sudden shift. Early wins will look like taking a shorter amount of time to fall asleep or fewer night wakings.”
• Intermediate methods: These approaches balance reassurance with more opportunities for independent practice. Many families see meaningful progress within 3–5 nights, with full results in 1-2 weeks.
• Firm methods: The firm methods typically produce the fastest results but require your baby to spend more time alone practicing their independent sleep skills. With these methods, babies typically learn to fall asleep independently within 1 week, with night wakings decreasing rapidly.
  
  

Jenn adds, “Regardless of what method you choose, consistency is the single biggest predictor of success. Babies learn through repetition, and when the bedtime routine or parental response changes night to night, it sends mixed signals that delay or stall progress.” 

Sticking with the plan—even when progress feels slow—helps your baby understand what to expect and accelerates their ability to settle independently. 

Signs Sleep Training Is Working

As your baby learns new independent sleep skills, you’ll start to see gradual but meaningful changes in both nighttime and daytime sleep. Tracking these shifts can help you stay encouraged and confident during the learning curve.

Here’s what to look for to know the sleep training process is working (especially when you’re second-guessing everything):

• Shorter settling times at bedtime. Your baby begins falling asleep more quickly, with less fussing or crying, because they’re learning how to settle independently.
• Fewer night wakings. Your baby still transitions between sleep cycles, but instead of fully waking and signaling for help, they resettle on their own more often.
• Longer stretches of continuous sleep. As independent skills strengthen, night sleep becomes more consolidated, and you may see long stretches of 4–8 hours depending on age.
• More predictable naps. Daytime sleep becomes easier to initiate and more consistent in length, which helps regulate your baby’s overall sleep pressure and mood.
• Calmer, more regulated daytime behavior. Babies who sleep better at night tend to be more content, alert, and adaptable during the day, with fewer meltdowns related to overtiredness.
  
  

Most families notice at least some of these positive changes within the first week, and progress typically accelerates once a consistent pattern is established.

Common Reasons Sleep Training Doesn’t Work

Sleep training is effective, but a few factors can interfere with progress:

• Inconsistency in routines
• Reverting to using sleep props
• Using multiple methods at once
• Underlying medical conditions (like reflux or allergies)
• Developmental milestones, which can cause regressions
• Sleep environment disruptions
• Overtiredness or incorrect wake windows
  
  

A clear plan—and follow-through—is essential.

FAQ: Does Sleep Training Work?

When families begin exploring sleep training, it’s completely normal to have questions—sometimes dozens of them. Parents want to understand whether sleep training is effective, how long it takes, what the process looks like, and whether it’s safe for their baby’s emotional well-being. This FAQ section breaks down the most common questions we hear from parents weighing their options, offering clear, evidence-based answers to help you make confident and informed decisions for your family.

Does Sleep Training Work For All Babies?

Most babies respond well when sleep training is developmentally appropriate, consistent, and aligned with their temperament. 

Does Sleep Training Mean My Baby Won’t Need Night Feeds?

No. Babies may still need overnight feeding after sleep training depending on age, development, and nutritional needs. If you have questions whether your child still needs a night feed, you should consult your pediatrician or Poppins 24/7 virtual pediatric medical team.

Will Sleep Training Harm Attachment?

No. Studies show no negative long-term effects on bonding, emotional development, or parent-child relationships. 

Will My Baby Cry During Sleep Training?

It is very common for babies to cry during sleep training. However, it’s important to remember that during sleep training, your baby will be safe, fed, and cared for. The crying is a form of communication that reflects frustration and protest to change—not fear or abandonment. 

Is One Sleep Training Method Better Than the Others?

All evidence-based methods are effective. The “best” method is the one you can do consistently and that fits your parenting style, baby’s age and temperament, and your sleep goals.

What If Sleep Training Doesn’t Work at First?

It’s common to hit setbacks. Reviewing wake windows, sleep environment, routines, and consistency usually resolves the issue. If progress stalls, personalized support can help.

Can I Sleep Train During Milestones Kike Rolling or Standing?

It depends. If your child is experiencing a sleep regression associated with the milestone, we recommend waiting to start or pausing the sleep training until the regression has resolved. 

Ready to Improve Your Baby’s Sleep? Poppins Can Help

Sleep training is most effective when you have expert guidance—and someone to support you through the tougher moments. Poppins provides:

• Personalized sleep training plans
• Real-time support from pediatric sleep specialists
• Evidence-based strategies tailored to your family
  
  

If you’re ready for smoother nights and more predictable days, we’re here to help.