Glycine (Amino Acid Supplement)
Glycine is the smallest amino acid that serves as a building block for proteins and plays crucial roles in collagen synthesis, neurotransmitter function, and detoxification pathways. Research suggests it may support sleep quality, cognitive function, and metabolic health, though many benefits require further clinical validation. Dietary supplements are not FDA-approved to diagnose, treat, cure, or prevent any disease. Consult your doctor before starting any supplement.
Key Takeaways
- Glycine is a non-essential amino acid that supports collagen synthesis, sleep quality, and detoxification, with typical dosing ranging from 3-10g daily depending on health goals
- Most effective when taken 1 hour before bedtime for sleep benefits (3-5g) or with meals for collagen support (higher doses up to 10g)
- Generally well-tolerated with minimal side effects, but can cause drowsiness and may interact with psychiatric medications and blood pressure drugs
- Natural dietary sources include meat, fish, dairy, and legumes, providing about 2g daily, while supplementation may be needed for therapeutic benefits
- Best suited for adults seeking improved sleep quality, joint health support, or metabolic benefits as part of a longevity-focused regimen
How to Take
Typical Dosage
3-5g daily based on clinical studies, though research has safely used up to 90g daily. Most longevity-focused protocols use 3g before bedtime for sleep benefits or 5-10g daily for metabolic support.
When to Take
Best taken on an empty stomach 30 minutes before bedtime for sleep benefits, or divided into 2-3 doses throughout the day for general health support
Why It Matters for Ages 50+
Adults over 50 may benefit from glycine supplementation as natural production declines with age, potentially affecting collagen synthesis, sleep quality, and detoxification capacity. Age-related changes in liver function and increased oxidative stress make glycine's role in glutathione production particularly relevant. However, older adults should start with lower doses due to potentially slower metabolism and increased medication interactions.
What to Look For
- Choose pharmaceutical-grade glycine powder or capsules from manufacturers with third-party testing for purity and contaminants
- Look for products certified by NSF, USP, or similar organizations to ensure accurate labeling and quality standards
- Verify the product contains pure L-glycine without unnecessary fillers, artificial colors, or allergens
- Store in a cool, dry place away from moisture, as glycine powder can clump and degrade when exposed to humidity
- Check expiration dates and buy from reputable suppliers, as amino acids can lose potency over time
Potential Interactions
Be aware of these potential interactions:
- Clozapine (antipsychotic): May decrease medication effectiveness - avoid combination
- CNS depressants (benzodiazepines, sleep aids, antihistamines): May enhance sedative effects - monitor for excessive drowsiness
- Blood pressure medications: May have additive hypotensive effects - monitor blood pressure closely
- Antipsychotic medications: May interfere with therapeutic effects - consult psychiatrist before use
- Anticoagulants: Limited data on bleeding risk interactions - consult pharmacist before combining with warfarin or other blood thinners
Who Should Avoid This Supplement
- Individuals with schizophrenia or other psychiatric disorders, especially those taking antipsychotic medications like clozapine
- People with severe liver disease or hepatic encephalopathy, as amino acid metabolism may be impaired
- Pregnant and breastfeeding women, due to insufficient safety data for supplemental doses during these periods
- Those with a history of seizure disorders, as glycine can affect neurotransmitter activity in the brain
Frequently Asked Questions
For sleep improvement, take 3-5g about 60 minutes before bedtime. For collagen support and general health benefits, 5-10g daily with meals is commonly used in studies.
A typical diet provides only about 2g of glycine daily from protein sources like meat, fish, and dairy. Therapeutic benefits shown in research typically require 3-10g daily, making supplementation necessary for most people.
Most people tolerate glycine well, but some may experience mild drowsiness, stomach upset, or headaches initially. Start with a lower dose and gradually increase to minimize any discomfort.
Sleep improvements may be noticed within days to weeks, while collagen and joint health benefits typically require 6-12 weeks of consistent use. Plasma glycine levels rise within 10 minutes of supplementation.
Both forms are effective, but powder allows for easier dose adjustment and is often more cost-effective. Glycine powder has a mildly sweet taste and dissolves well in water or other beverages.
Glycine appears safe for long-term use in healthy adults at recommended doses, as it's a naturally occurring amino acid. However, consult your healthcare provider for extended use, especially if you have underlying health conditions.