Is Glycine the Next Sleep Hack?

Move over, melatonin. You may have seen chatter online lately about using glycine as a sleep supplement. This amino acid is naturally found in protein-rich foods -- like bone broth, chicken, eggs, milk, lentils, beans, tofu, spinach, and quinoa -- and plays several important roles in the body. But could taking it before bed actually help you sleep?

First, how would it help? One theory is that glycine helps lower core body temperature by increasing blood flow to the skin. Because the body’s natural temperature drop is part of preparing for sleep, this thermoregulatory effect could make it easier to fall asleep. In short, it could support your body’s natural sleep-wake cycle. Glycine may also increase serotonin, a neurotransmitter involved in sleep regulation. 

There has been some research looking at this, some newer, some older. One found that taking 3 grams of glycine before bedtime may improve subjective sleep quality, sleep efficiency and the time it takes to fall asleep. Some research also suggests it may reduce next-day sleepiness and fatigue. A review from this year found that the evidence is promising but that larger, better-designed studies are needed. 

While glycine is promoted as a cure for insomnia, it’s too early to call it a proven sleep solution. For people with insomnia or other persistent sleep problems, stick with the glycine proven treatments that work for you and talk with your doctor about adding glycine as a supplement. Glycine is generally considered safe and well tolerated, but supplements aren’t right for everyone, particularly if you’re pregnant, breastfeeding or taking medications.

If you do end up giving it a try, it’s best to take glycine 30-60 minutes before bed. And if you’re not already, give these bedtimes tips a try:

•    Create a bedtime routine and stick to that schedule, waking up and going to bed at the same time each night.
•    Shut down all electronics at least one hour before bedtime.
•    Save the bedroom for sleep and relaxation with low to minimal lighting. Darkness cues the body to release melatonin, a natural sleep hormone, while light suppresses it.
•    Watch what you eat and drink before bedtime. Avoid heavy meals, caffeine, and alcohol at least 3 hours before bed.