Taking 15g of glycine-rich collagen peptides before bedtime reduced nighttime awakenings and improved morning cognitive accuracy in athletic men with sleep complaints.
21.3 vs 29.3nighttime awakenings with collagen peptides vs placebo (polysomnography)
What the researchers found
Collagen peptides reduced polysomnographic awakenings from 29.3 to 21.3 per night and improved next-morning Stroop test accuracy to 100% vs 97% with placebo.
Why it matters
Sleep disruption is extremely common among active individuals and has cascading effects on recovery and cognitive performance. This study suggests a simple, well-tolerated nutritional intervention may help reduce sleep fragmentation.
The numbers in context
13 males, age 24±4 years, training 7±3 hours/week, Athens Insomnia Scale score 9±2. Dose: 15 g collagen peptides daily for 7 nights.
How the study worked
Randomized, crossover design with 13 athletic males taking 15g collagen peptides or placebo before bed for 7 nights, measured with polysomnography, actigraphy, sleep diaries, cognitive tests, core temperature, and inflammatory/endocrine markers.
Who was studied
Athletic males aged 24±4 years with self-reported sleep complaints
What this study cannot tell us
Very small sample size (13 men); only male athletes studied; short 7-night protocol; cognitive improvement was modest and limited to one test; no glycine-only comparison to isolate the active component; crossover washout period only 7 days.
How to read the evidence
Preliminary evidence from a well-designed but very small crossover RCT (N=13). The polysomnography data is objective and high-quality, but the sample size limits generalizability.
When this study was published
Published in 2024, representing emerging research on collagen peptides beyond their traditional musculoskeletal applications.
The bigger picture
Glycine, the most abundant amino acid in collagen peptides, has emerging evidence for sleep-promoting effects through thermoregulation and neurotransmitter modulation. This study provides the first polysomnography evidence that collagen peptide supplementation reduces sleep fragmentation in active adults.
Questions still open
- Is glycine specifically responsible, or do other collagen peptide components contribute to sleep benefits?
- Would these effects scale in larger, more diverse populations including women and older adults?
- Does reducing sleep fragmentation translate to better athletic recovery and performance metrics?
Common questions
Can collagen peptides really help you sleep better?
How much collagen peptide should you take for sleep benefits?
Read the original research
Collagen peptide supplementation before bedtime reduces sleep fragmentation and improves cognitive function in physically active males with sleep complaints.
European journal of nutrition, 63(1), 323-335
Citation
Thomas, Craig; Kingshott, Ruth N; Allott, Kirsty M; Tang, Jonathan C Y; Dunn, Rachel; Fraser, William D; Thorley, Josh; Virgilio, Nicolina; Prawitt, Janne; Hogervorst, Eef; Škarabot, Jakob; Clifford, Tom. (2024). Collagen peptide supplementation before bedtime reduces sleep fragmentation and improves cognitive function in physically active males with sleep complaints.. European journal of nutrition, 63(1), 323-335. https://doi.org/10.1007/s00394-023-03267-w