the glycine thing, or why i started drinking collagen at night

I used to drink collagen in the morning because that is when you drink things that are good for you. Coffee, water, the supplement. It felt correct.

Then I went looking for why collagen tastes faintly sweet on its own, which led me to glycine, which led me into a set of sleep studies I did not expect to find. My can moved to the evening and it has stayed there.

collagen is about a third glycine

Glycine is the smallest amino acid there is, and collagen is unusually loaded with it. Roughly every third position in the collagen chain is a glycine, and that is a structural requirement rather than a coincidence. It is the only amino acid small enough to fit inside the tight interior of the triple helix. Nothing bulkier works.

Which means when you drink a real dose of collagen, you are taking in several grams of glycine at the same time. That is not an added ingredient or a marketing angle. It is simply what the molecule is built from.

what the glycine research found

In 2006 and again in 2007, researchers gave volunteers who slept badly three grams of glycine before bed. Participants reported better sleep quality and less daytime fogginess. In the 2007 study, published in Sleep and Biological Rhythms, polysomnography backed it up: shorter time to fall asleep, and faster entry into slow wave sleep, which is the deep restorative stage everyone is trying to get more of.

A 2012 review in the Journal of Pharmacological Sciences summarised the case, and in 2015 a paper in Neuropsychopharmacology traced the mechanism. It comes down to temperature. Your core body temperature has to fall for you to drop off properly, and glycine appears to help that fall happen by acting on receptors in the suprachiasmatic nucleus, the part of the brain that runs your body clock.

Cooling down to fall asleep is one of the oldest and best understood facts in sleep science. Glycine appears to work with it rather than against it, which is a very different proposition from a sedative.

why the evening version of this drink works

A lot of things that are good for you are impossible to have at nine at night. Coffee is out. A protein shake sits heavy. Anything with sugar in it wakes you up an hour later.

LÉS has no caffeine at all, ninety calories, and one gram of sugar with nothing added. It is cold and lightly sparkling. It closes out an evening the way a glass of wine used to, without the part where you sleep badly and feel it at seven the next morning.

That is genuinely why it stuck for me. The glycine is the reason I tried it at night. The fact that it is a pleasure rather than a chore is the reason I am still doing it a year later, and consistency is the whole game with collagen.

the research i leaned on

• Yamadera W, Inagawa K, Chiba S, et al. Glycine ingestion improves subjective sleep quality in human volunteers, correlating with polysomnographic changes. Sleep and Biological Rhythms. 2007;5(2):126-131.
• Inagawa K, Hiraoka T, Kohda T, et al. Subjective effects of glycine ingestion before bedtime on sleep quality. Sleep and Biological Rhythms. 2006;4(1):75-77.
• Kawai N, Sakai N, Okuro M, et al. The sleep-promoting and hypothermic effects of glycine are mediated by NMDA receptors in the suprachiasmatic nucleus. Neuropsychopharmacology. 2015;40(6):1405-1416.
• Bannai M, Kawai N. New therapeutic strategy for amino acid medicine: glycine improves the quality of sleep. Journal of Pharmacological Sciences. 2012;118(2):145-148.

LÉS is a beverage and not a sleep aid, and nothing here is medical advice.