Bone Broth for Sleep Quality

Research suggests that glycine, an amino acid found in meaningful concentrations in bone broth, may support sleep quality through several proposed mechanisms, including lowering core body temperature and modulating inhibitory pathways in the nervous system. The available evidence consists primarily of narrative and systematic reviews synthesizing animal and human data, along with a small number of randomized controlled trials — most of which are limited by small sample sizes, short durations, and in some cases, multi-ingredient designs that make it difficult to isolate glycine's specific contribution. Studies indicate that glycine supplementation has been associated with reductions in nighttime awakenings, faster sleep onset, and modest improvements in next-day cognitive performance, though findings are not consistent across all measured outcomes, and several larger sleep parameters such as total sleep duration and sleep efficiency showed no significant differences from placebo in controlled trials. Overall, the direction of the literature is cautiously supportive, but researchers across multiple reviews consistently note that larger, more rigorously designed clinical trials are needed before confident conclusions can be drawn about glycine — and by extension, glycine-rich foods like bone broth — as a reliable tool for improving sleep.