Supplement
Glycine
Glycine shows consistent promise for sleep quality, with multiple small studies finding it reduces time to fall asleep and improves sleep architecture when taken before bed. As the main amino acid in collagen, it may also support skin and joint health during menopause, though this evidence is more limited. At 3-5g nightly, it's inexpensive, well-tolerated, and worth trying for sleep struggles.
30-second summary
Glycine shows consistent promise for sleep quality, with multiple small studies finding it reduces time to fall asleep and improves sleep architecture when taken before bed. As the main amino acid in collagen, it may also support skin and joint health during menopause, though this evidence is more limited. At 3-5g nightly, it's inexpensive, well-tolerated, and worth trying for sleep struggles.
sleep problems — mixedjoint pain — weakskin changes — weak
Overall: Mixed evidence
Randomised controlled trials
Multiple small randomized trials consistently show glycine improves sleep onset time and subjective sleep quality at 3g doses.
Limited observational data exists on glycine supplementation in general populations.
No comprehensive meta-analyses have been conducted specifically on glycine for sleep or menopause symptoms.
Menopause-specific trials
No studies have specifically examined glycine supplementation in perimenopausal or menopausal women.
What we do not know
No studies have tested glycine specifically in perimenopausal or postmenopausal women. The optimal dose for sleep hasn't been established - studies used 3g but higher doses haven't been compared. Long-term safety data beyond 12 weeks is missing. We don't know if glycine works better than other sleep aids like magnesium or melatonin. The connection between oral glycine and collagen production hasn't been proven in humans.
How it is used
Common dose range
3-5g taken before bed
Notes on dosing
Mix in water — glycine is sweet-tasting and dissolves easily. Works within the first week for most people who respond.
Get it from food first
Food sources are better absorbed than most supplements and come with co-factors that support the same pathways. If you eat two or three of these consistently, you may not need a supplement at all.
Bone broth
1-2 cups
varies widely by preparation method
Gelatin powder
1 tablespoon
about 2-3g glycine
Pork skin
1 ounce
highest natural source
Chicken skin
1 ounce
good source when eating whole chicken
Fish skin
1 ounce
often discarded but glycine-rich
Traditional cooking methods
Using bones, cartilage, and connective tissues in slow-cooked meals naturally increases glycine intake
Nose-to-tail eating
Incorporating organ meats and less popular cuts provides more glycine than muscle meat alone
What depletes Glycine
High sugar intake may interfere with glycine metabolism. Excessive alcohol consumption can deplete glycine stores. Chronic stress increases glycine needs for glutathione production.
Interactions and cautions
No significant interactions noted at recommended doses.
Rose bottom line
"If sleep is your biggest struggle, glycine has more consistent evidence than many other supplements - and it's gentle enough to try without major risk. Start with 3g about 30 minutes before bed and see if it helps you fall asleep faster. Your body knows what good sleep feels like, even if it's been a while."