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Published on: 3/2/2026

Can’t Sleep? Why Your Brain Needs Glycine & Medically Approved Next Steps

Glycine is a calming neurotransmitter that helps lower core body temperature and quiet neural activity, and small clinical studies suggest about 3 grams taken at bedtime can improve sleep quality without acting like a sedative.

There are several factors to consider. See below for medically approved next steps like CBT-I, screening for sleep apnea if you snore or feel excessively sleepy, optimizing sleep habits, addressing mental health, and reviewing medications, plus the red flags that mean you should seek urgent care.

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Explanation

Can't Sleep? Why Your Brain Needs Glycine & Medically Approved Next Steps

If you can't sleep, you're not alone. Millions of adults struggle with falling asleep, staying asleep, or waking up feeling unrefreshed. While stress, screens, and late-night habits play a role, there's also a biological side to sleep that many people overlook.

One key player? Glycine.

Glycine is a simple amino acid that your body naturally produces. It may not get as much attention as melatonin, but research shows glycine plays an important role in calming the brain and supporting healthy sleep patterns.

Let's break down what glycine does, how it affects sleep, and what medically approved next steps you should consider.


What Is Glycine?

Glycine is one of the smallest amino acids in the body. It helps:

  • Build proteins
  • Support nervous system function
  • Regulate inflammation
  • Assist with detoxification in the liver
  • Promote stable blood sugar levels
  • Act as a neurotransmitter in the brain

Most importantly for sleep, glycine functions as an inhibitory neurotransmitter, meaning it helps quiet brain activity.

Think of it as one of the brain's natural "brakes."


How Glycine Supports Sleep

Research suggests glycine may improve sleep in several ways:

1. Helps Lower Core Body Temperature

To fall asleep, your body temperature naturally drops. Glycine has been shown in clinical studies to:

  • Increase blood flow to the hands and feet
  • Help the body release heat
  • Lower core body temperature

This temperature drop is one of the biological signals that it's time for sleep.


2. Calms the Nervous System

Glycine works with receptors in the brainstem and spinal cord to:

  • Reduce overactive nerve signaling
  • Promote relaxation
  • Support deeper, more stable sleep cycles

If your brain feels "wired but tired" at night, glycine may help counter that overstimulation.


3. Improves Sleep Quality (Not Just Quantity)

Small clinical studies have shown that taking glycine before bed may:

  • Reduce the time it takes to fall asleep
  • Improve subjective sleep quality
  • Decrease daytime sleepiness
  • Improve cognitive performance the next day

Importantly, glycine does not act as a sedative. It doesn't "knock you out." Instead, it supports your body's natural sleep processes.


Why Might You Be Low in Glycine?

True glycine deficiency is rare. However, modern lifestyles may increase your need for it.

You may benefit from additional glycine support if you:

  • Eat very little protein
  • Avoid collagen-rich foods (bone broth, connective tissue meats)
  • Experience chronic stress
  • Have high inflammation
  • Have poor sleep habits
  • Consume high amounts of processed food

Glycine is also a major component of collagen. Many people consume far less collagen than previous generations did, which may reduce glycine intake.


Food Sources of Glycine

Before turning to supplements, consider dietary sources.

Foods rich in glycine include:

  • Bone broth
  • Chicken skin
  • Pork skin
  • Gelatin
  • Collagen peptides
  • Red meat
  • Fish
  • Legumes

A protein-diverse diet often provides adequate glycine for most healthy adults.


Should You Take a Glycine Supplement?

Clinical research has used glycine doses around 3 grams before bedtime.

Some potential benefits:

  • May improve sleep onset
  • May enhance sleep satisfaction
  • Generally well tolerated
  • Not habit-forming

However, glycine is not a cure-all. If insomnia is driven by anxiety, sleep apnea, depression, chronic pain, or medical conditions, glycine alone will not fix the root cause.

Always speak to a doctor before starting supplements if you:

  • Take psychiatric medications
  • Have kidney or liver disease
  • Are pregnant or breastfeeding
  • Have complex medical conditions

When Sleep Problems Signal Something Bigger

Occasional poor sleep is normal. But ongoing sleep problems can indicate a sleep disorder or underlying health issue.

Warning signs include:

  • Snoring with choking or gasping
  • Stopping breathing during sleep (reported by a partner)
  • Severe daytime sleepiness
  • Restless or crawling sensations in legs at night
  • Frequent nighttime awakenings
  • Morning headaches
  • Mood changes or irritability
  • Trouble concentrating

These could signal:

  • Obstructive sleep apnea
  • Insomnia disorder
  • Restless legs syndrome
  • Circadian rhythm disorders
  • Depression or anxiety-related sleep disturbance

If you're experiencing persistent symptoms and want to better understand what might be causing your sleep problems, Ubie's free AI-powered Sleep Disorder symptom checker can help you identify potential causes and determine whether it's time to consult with a healthcare professional.

This personalized assessment takes just a few minutes and can guide your next steps.


Medically Approved Next Steps for Better Sleep

If glycine alone isn't solving the problem, here are evidence-based steps that doctors commonly recommend:

1. Cognitive Behavioral Therapy for Insomnia (CBT-I)

This is considered the gold standard treatment for chronic insomnia. It helps:

  • Retrain your brain to associate bed with sleep
  • Reduce nighttime anxiety
  • Improve sleep efficiency
  • Correct harmful sleep habits

CBT-I is more effective long term than sleeping pills.


2. Rule Out Sleep Apnea

If you snore loudly, feel exhausted during the day, or wake gasping, ask your doctor about a sleep study.

Untreated sleep apnea increases the risk of:

  • High blood pressure
  • Heart disease
  • Stroke
  • Type 2 diabetes

This is not something to ignore.


3. Address Stress and Mental Health

Anxiety and depression commonly disrupt sleep.

If racing thoughts keep you awake, consider:

  • Therapy
  • Stress-reduction training
  • Mindfulness practices
  • Physician-guided medication if appropriate

Sleep and mental health are deeply connected.


4. Optimize Sleep Hygiene

Basic, but powerful:

  • Keep a consistent sleep schedule
  • Avoid screens 1–2 hours before bed
  • Limit caffeine after noon
  • Avoid heavy meals late at night
  • Keep your bedroom cool and dark

Remember: glycine works best when paired with healthy sleep habits.


5. Review Medications

Some medications interfere with sleep, including:

  • Stimulants
  • Steroids
  • Certain antidepressants
  • Decongestants

If sleep worsened after starting a medication, talk to your doctor.


What Glycine Can — and Cannot — Do

Let's be realistic.

Glycine may help if:

  • You have mild sleep difficulty
  • You feel overstimulated at night
  • Your sleep quality is poor but not severely disrupted
  • You want a non-habit-forming option

Glycine will not fix:

  • Obstructive sleep apnea
  • Severe clinical insomnia
  • Untreated depression
  • Chronic pain conditions
  • Hormonal disorders

It's a supportive tool — not a medical replacement.


When to Speak to a Doctor Immediately

Do not delay medical care if you experience:

  • Chest pain
  • Shortness of breath at night
  • Severe depression or suicidal thoughts
  • Falling asleep while driving
  • Episodes of confusion
  • Sudden severe headaches

These could indicate serious or life-threatening conditions.

Always speak to a doctor about anything that feels severe, unusual, or progressively worsening.


The Bottom Line

If you can't sleep, your brain chemistry may be part of the story — and glycine plays a real role in calming neural activity and supporting natural sleep cycles.

Glycine:

  • Helps lower core body temperature
  • Calms the nervous system
  • May improve subjective sleep quality
  • Is generally safe when used appropriately

But sleep problems are rarely caused by just one thing.

Use glycine as a supportive strategy — not a shortcut. Pair it with good sleep hygiene, stress management, and medical evaluation when needed.

And if you're unsure whether your sleep issues signal something more serious, consider starting with a free online Sleep Disorder symptom checker to guide your next step.

Good sleep is not a luxury. It's a foundation of long-term brain, heart, and metabolic health. If yours is struggling, take it seriously — and don't hesitate to speak to a qualified healthcare professional for personalized care.

(References)

  • * Inose H, Takeda N, Terashima M, et al. Effects of Glycine Ingestion on Human Sleep and Health: A Systematic Review. *Nutrients*. 2024 Jan 19;16(2):319. doi: 10.3390/nu16020319. PMID: 38257039.

  • * Yamadera W, Sato M, Suzuki H, et al. Glycine ingestion improves subjective sleep quality in individuals with insufficient sleep: A double-blind, randomized, placebo-controlled trial. *Sleep Biol Rhythms*. 2021;19(4):465-472. doi: 10.1007/s41105-021-00331-1. PMID: 34107567.

  • * Schutte-Rodin S, Manconi M, O'Brien J, et al. Clinical Practice Guideline for the Pharmacologic Treatment of Insomnia: An Update. *J Clin Sleep Med*. 2021 Jun 1;17(6):1127-1130. doi: 10.5664/jcsm.9324. PMID: 33998144.

  • * Kolla BP, Scharf SM. Cognitive Behavioral Therapy for Insomnia (CBT-I) in Adults: An Update for Clinicians. *Mayo Clin Proc*. 2020 Feb;95(2):331-344. doi: 10.1016/j.mayocp.2019.06.024. Epub 2019 Oct 11. PMID: 31607590.

  • * Mitchell MD, Johnson JA, Redeker NS. Non-Pharmacological Interventions for Insomnia. *Curr Treat Options Neurol*. 2018 Jan 20;20(1):3. doi: 10.1007/s11940-018-0487-y. PMID: 29352495.

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