Glycine for Sleep and Recovery

1. What Is Glycine?

Glycine is an amino acid that acts as a calming neurotransmitter and is a building block of collagen. Small studies suggest it may lower core body temperature and improve sleep quality.

2. Evidence

• Small studies show improved subjective sleep quality
• Less daytime sleepiness after restricted sleep in some studies
• Supports collagen synthesis as part of the diet

3. Dosage

Sleep studies used about 3 g before bed. It's a mildly sweet powder that dissolves easily in water or tea and is generally well tolerated.

4. How Glycine May Improve Sleep

Glycine may support sleep by lowering core body temperature, which helps signal the body that it's time to rest, and by acting as an inhibitory neurotransmitter in the brain. In small studies, people taking about 3 grams of glycine before bed reported feeling more rested and less sleepy the next day, even after restricted sleep.

Glycine is not a sedative, so it's unlikely to cause grogginess the next morning.

5. Glycine and Collagen

Glycine makes up about one-third of the amino acids in collagen. Adequate glycine supports collagen production for skin, tendons and joints. Collagen supplements and bone broth are rich in glycine, which is one reason some people take collagen before bed.

6. Glycine Safety

Glycine is generally safe for healthy adults at typical doses. People taking clozapine or other medications should consult a doctor. Pregnant women should check with their healthcare provider.

7. How to Take Glycine

Dissolve 3 grams in water or herbal tea 30 to 60 minutes before bed.

8. Glycine for Recovery

Better sleep supports muscle recovery, hormone balance and training performance. By potentially improving sleep quality, glycine may indirectly aid recovery. Some research also explores glycine's role in reducing inflammation and supporting metabolic health, though more studies are needed.

Glycine is often combined with magnesium in magnesium glycinate supplements for relaxation and sleep.

9. Our Recommendation

Try 3 grams before bed for two weeks to see if your sleep quality improves.

10. Glycine Food Sources

Glycine is found in collagen-rich foods like bone broth, gelatin, chicken skin and pork rinds, as well as meat, fish, dairy and legumes. Modern diets often contain less collagen-rich food than traditional diets, which is one reason some people supplement.

A cup of bone broth or a serving of gelatin before bed provides glycine naturally.

11. Glycine vs Melatonin

Melatonin is a hormone that shifts your sleep timing and is often used for jet lag. Glycine is an amino acid that may improve sleep quality and next-day alertness without acting as a hormone. Some people use glycine as a gentle alternative to melatonin for nightly use.