Glycine

2007: measuring sleep beyond feeling

In 2007, Yamadera and colleagues tested 3 g of glycine before bed in volunteers who were dissatisfied with their sleep. They evaluate feelings and sleep recordings. Improvements are observed in certain criteria, including the time it takes to fall asleep. This work fuels interest in the supplement, without providing sufficient evidence on its own to treat insomnia.

2012: examining the aftermath of a shortened night

A 2012 trial studies glycine in volunteers with partially sleep-restricted sleep. It found favorable results on certain measures of fatigue or alertness, but not on all tests or at all times. The experience concerns a short and specific situation; it does not show that a supplement allows you to live sustainably with less sleep.

2023: replace the results in their level of proof

A systematic review published online in 2023 examines the effects of glycine in several physiological systems in adults. For the sleep of healthy people, she highlights small samples and a high risk of bias. The results obtained in diseased populations or with other doses do not allow us to recommend general supplementation for recovery or aging.

2026: literature still sparse

A scoping review published in September 2026 lists only three trials investigating supplemental glycine and sleep-related outcomes. Each reports at least one favorable outcome, but the authors call for larger trials with standardized measurements. The path remains plausible; the number of available jobs still does not allow predicting a reliable profit for each user.