Key Takeaways
Clinical-Strength Glycine
Each sachet delivers 3000mg of glycine, the sleep amino acid that Ajinomoto's research shows helps you reach deep sleep approximately twice as fast as without supplementation.
Simple Bedtime Routine
Take one grapefruit-flavored granule sachet with water before bed. Easy-to-dissolve formula makes it simple to incorporate into your nightly routine.
Japan's Trusted Quality
From Ajinomoto, a company with over 100 years of amino acid research. Manufactured in Japan with Informed Choice anti-doping certification.
3 Recovery Powers
Clinically studied to support fatigue reduction during the day (10am-6pm), improved work efficiency, and reduced daytime sleepiness.
Best For
Those who feel unrested despite sleeping enough hours, experience afternoon fatigue, or want to support their body's natural sleep-wake cycle for better daily performance.
Market Validation
Japan's #1 sleep support supplement for 12 consecutive years with 2.83 million satisfied users. 85% of customers report feeling the benefits.
Is This Right For You?
Recommended For
Glyna is designed for those seeking natural glycine sleep support to improve sleep quality and daytime vitality.
If you're waking up feeling unrested despite getting adequate hours of sleep and want to improve your sleep quality naturally
If you've noticed increased daytime fatigue or sleepiness that affects your afternoon productivity and focus
If you're looking for a deep sleep supplement backed by clinical research from a trusted Japanese pharmaceutical company
If you're experiencing work efficiency decline due to poor sleep quality and want to feel sharper throughout the day
If you want a simple, one-sachet-per-day sleep routine without complicated timing or multiple pills to manage
If you're an athlete or professional requiring anti-doping certified supplements (Informed Choice certified)
If you're seeking a glycine supplement with clinically-studied dosage (3000mg) rather than arbitrary amounts
If you value Japanese quality and want a sleep supplement trusted by millions of users over more than a decade
Why It Works
Benefits
Glyna delivers comprehensive sleep and recovery support through Ajinomoto's amino acid expertise.
Reach Deep Sleep Faster
Glycine helps your body reach deep sleep (slow-wave sleep) approximately twice as fast as without supplementation. Clinical studies show that participants taking 3000mg glycine before bed reached deep sleep significantly faster than the control group, leading to more restorative sleep cycles.
Clinically validated (p<0.05)Reduce Daytime Fatigue
Even when sleep time is limited, Glyna helps reduce the feeling of fatigue during active hours (10am-6pm). Studies with sleep-restricted participants showed significantly lower fatigue scores when taking glycine compared to placebo, helping you feel more energized throughout the day.
Published research (Bannai et al., 2012)Improve Work Efficiency
Glycine supplementation supports better cognitive performance even under sleep pressure. Clinical testing showed improved reaction times on computer tasks throughout the day, from morning to evening, supporting sustained work efficiency and mental sharpness.
Peer-reviewed studyEnhance Sleep Satisfaction
Users report improved sleep satisfaction and quality of rest. Clinical evaluation using the St. Mary's Hospital Sleep Questionnaire showed significantly higher satisfaction scores for the glycine group, indicating more refreshing and restorative sleep experiences.
Consumer validated (85% report benefits)The Science
How It Works
Understanding how glycine supports your body's natural sleep mechanisms.
3 Recovery Powers
The key is that glycine doesn't just help you fall asleep - it improves the quality of the sleep you do get, so each hour of rest delivers more recovery benefit.
Deep Sleep Acceleration
Clinical polysomnograph testing showed that participants taking 3000mg glycine reached deep sleep at approximately twice the speed of the control group.
3 Sleep Powers
- Rapidly reaching deep sleep
- Improved feeling of restfulness (jukumin-kan)
- Better sleep rhythm and habits
The Science
Research & Evidence
Over 100 years of Ajinomoto amino acid research supports Glyna's formulation.
Fatigue Reduction Study—Double-blind study showed significantly reduced fatigue scores during active hours (10am-6pm) for glycine group vs placebo (p<0.05). Bannai M et al., Frontiers in Neurology, 2012.
Work Efficiency Study—Participants taking glycine showed faster reaction times on computer tasks throughout the day, supporting sustained cognitive performance. Bannai M et al., 2012.
Deep Sleep Acceleration—Polysomnograph testing showed glycine helped reach deep sleep approximately 2x faster than control (p<0.05). Yamadera W et al., Sleep and Biological Rhythms, 2007.
Sleep Satisfaction Improvement—St. Mary's Hospital Sleep Questionnaire showed significantly higher satisfaction scores for glycine group (p<0.05). Yamadera W et al., 2007.
A Note on Evidence: We present research on ingredients, not specific product claims. Individual results may vary. This supplement is not intended to diagnose, treat, cure, or prevent any disease.
Ingredient Research Highlights
GLYCINE
Glycine is the simplest amino acid, naturally found in foods like scallops and fish. Ajinomoto discovered that supplemental glycine (3000mg) helps the body reach deep sleep more quickly, improving overall sleep quality and next-day recovery.
Over 100 years of Ajinomoto amino acid researchCONSUMER VALIDATION
Glyna has been Japan's #1 sleep support supplement for 12 consecutive years (Fuji Keizai market research). Over 2.83 million customers have used Glyna, and 85% of surveyed users report feeling the benefits.
Fuji Keizai H&B Foods Marketing Handbook 2014-2025CLINICAL RESEARCH
Multiple peer-reviewed studies support glycine's sleep benefits. Research published in Frontiers in Neurology (2012) and Sleep and Biological Rhythms (2007) demonstrate improvements in sleep quality, daytime fatigue, and work efficiency.
Peer-reviewed journalsThe Story
About Brand Story
Ajinomoto Co., Inc.
Their sleep supplement Glyna emerged from a serendipitous 2002 discovery when researchers noticed glycine — used as a placebo — unexpectedly improved sleep quality. This patented formulation has achieved eleven consecutive years as Japan's top-selling sleep support supplement. Backed by clinical studies demonstrating enhanced deep sleep and reduced daytime fatigue, Glyna exemplifies Ajinomoto's century-long commitment to amino acid-based wellness innovation.
Our Curation Process
Why We Selected This Product
Every product at Naturacare undergoes rigorous evaluation before joining our collection.
信頼性
Reliability
From Ajinomoto, Japan's most trusted food and amino acid company with over 100 years of research heritage. The Glyna formulation is backed by peer-reviewed clinical studies published in scientific journals.
実績
Proven Track Record
12 consecutive years as Japan's #1 sleep support supplement with 2.83 million satisfied users. This isn't a new product making bold claims - it's a proven formula with over a decade of market leadership.
品質
Quality Assurance
Functional Food certification (A42) from Japan's Consumer Affairs Agency, plus Informed Choice anti-doping certification. Every batch meets rigorous quality standards expected of the Ajinomoto name.
Our Promise: We don't just import popular Japanese supplements - we investigate each product's formulation, manufacturing standards, and real-world reputation in Japan.
We selected Glyna because it represents the best of Japanese supplement science - clinical-strength dosing, peer-reviewed research, and trusted heritage from a company that has dedicated a century to understanding amino acids.
Why Japan
The Japanese Advantage
Japan's supplement industry operates under some of the world's strictest quality standards. Combined with a cultural dedication to craftsmanship and centuries of wellness traditions, Japanese supplements represent a level of quality that's difficult to find elsewhere.
Rigorous Quality Standards
Japanese regulations require comprehensive testing at every stage of production, with standards that often exceed international requirements.
GMP-Certified Manufacturing
All our products come from facilities that meet Japan's strict GMP (Good Manufacturing Practice) certification requirements.
Centuries of Tradition
Many Japanese supplements draw on ingredients and formulations refined over generations, combining ancient wisdom with modern science.
Transparent Sourcing
Japanese manufacturers maintain complete traceability, so you know exactly where every ingredient comes from.
Directions
How to Use
Simple one-sachet routine for better sleep.
The grapefruit-flavored granules dissolve easily and can be taken directly or mixed with water.
For best results, make it part of your consistent nightly routine.
Tips for Best Results
- Take Glyna at the same time each night to establish a sleep routine
- Keep a sachet by your bedside for convenient access
- The granules can be taken directly - the grapefruit flavor is naturally sweet from glycine (no sugar added)
- Consistency is key - glycine's benefits compound with regular use
- Store in a cool, dry place away from direct sunlight
- Allow 1-2 weeks of consistent use to notice improvements in sleep quality
What's Inside
Ingredients
Simple, transparent formulation with clinical-strength glycine.
Glycine
Sleep amino acid that supports deep sleep - the clinically-studied dosage
Low Calorie
Minimal calorie content per sachet with zero fat
Allergen-Free
Does not contain any of the 28 designated allergens under Japanese food labeling law
Ingredients: Glycine, Citric Acid, Natural Flavor
Allergen Information: Does NOT contain: Any of the 28 designated allergens including eggs, milk, wheat, peanuts, tree nuts, fish, shellfish, soy, and others. Note: No grapefruit juice is contained - the flavor is from natural flavoring.
Important Information
Safety & Precautions
Please read before use.
Allergies
This product does not contain any of the 28 designated allergens under Japanese food labeling law. However, if you have any known allergies or sensitivities, please review the ingredient list before use.
Pregnancy & Nursing
This product was not developed for pregnant women (including those planning pregnancy), nursing mothers, or individuals under 18. Consult your healthcare provider before use.
Medications
If you are taking prescription medications, please consult your physician or pharmacist before starting this supplement.
Dosage
Take 1 sachet per day as directed. Do not exceed the recommended daily amount.
Discontinue Use
If you experience any adverse effects, discontinue use immediately and consult your healthcare provider.
Disclaimer
This is a Functional Food (機能性表示食品), not a medicine. It is not intended to diagnose, treat, cure, or prevent any disease. Maintain a balanced diet with staple foods, main dishes, and side dishes.
Storage
Keep in a cool, dry place away from direct sunlight. Keep out of reach of children and pets.
Details
Product Specifications
Questions
Frequently Asked Questions
These findings are published in peer-reviewed journals including Frontiers in Neurology and Sleep and Biological Rhythms.
Ajinomoto developed this dosage based on their research showing it's the effective amount for reaching deep sleep faster and improving sleep quality.
Glyna focuses on clinically-validated glycine dosing (3000mg) with research showing improved sleep quality, reduced fatigue, and better work efficiency.
Taking it consistently at bedtime helps establish a healthy sleep routine and allows glycine to support your natural sleep cycle.
Glyna contains glycine, which addresses the quality of sleep rather than just helping you fall asleep - supporting more restorative rest and better next-day recovery.
The sweet taste is from glycine itself, not sugar, so it doesn't contribute to tooth decay. Always follow recommended dosage guidelines.
Users report better sleep satisfaction, reduced daytime fatigue, and improved morning refreshment. The key is improved quality, not necessarily longer sleep time.
We ship directly from verified Japanese sources with full authenticity guarantee and customer support.
Trusted by 2.83 million Japanese consumers over 12+ years.
For best results, take Glyna consistently as part of your nightly routine and allow your body to adjust.