Supplements›Protein, amino acids & fitness

Glycine for sleep and healthy aging: how to take it

Glycine is an amino acid that calms the nervous system, so many people who have trouble falling asleep look for it. Taken with NAC, it also provides the raw materials for glutathione, the body's own antioxidant, so it's used for healthy aging too. It comes as a sweet-tasting powder that's easy to mix into drinks.

Who it’s for

People who have trouble falling asleep, and people interested in healthy aging and muscle

Daily dose

Follow the product label

When

In the evening if sleep is your goal

Best form

Sweet-tasting powder — mix into water or a drink

What is glycine?

Glycine is one of the amino acids that make up protein.

In the brain, it's used to calm the nerves (inhibitory signaling). In simple terms, it's a building block your brain uses to tell overexcited nerves, "Okay, time to rest."

So people mainly take it for two reasons:

  • Sleep: To calm the body and mind
  • Healthy aging and muscle: As a raw material for making glutathione and muscle

Glycine for sleep: an add-on for stubborn insomnia

Sleep supplements usually start with a basic stack like magnesium, B vitamins and omega-3. When insomnia is severe, 5-HTP and glycine are sometimes added on top.

Compared with GABA, another calming supplement, glycine tends to have fewer side effects, so it's an easier first thing to try.

Glycine + NAC = raw materials for glutathione

Glutathione is the body's main antioxidant. It clears free radicals (compounds that "rust" your cells).

Some experts say that instead of taking glutathione directly, it's more effective to give your body the raw materials to make its own. Those raw materials are NAC and glycine.

ApproachWhat happens
Taking glutathione directlyMuch of it is broken down during digestion
NAC + glycineSupplies the raw materials so your body can make glutathione itself

How to take glycine: powder is easiest

Glycine powder tastes sweet, so it's easy to take.

  1. Mix it into water or a drink.
  2. Mixing it with inulin powder, a fiber for gut health, makes it taste even better and easier to stick with.
  3. If sleep is your goal, take it in the evening.
  4. Follow the dose on the product label.

Combinations

Works well with: NAC (N-Acetylcysteine), 5-HTP, Magnesium

Frequently asked questions

Is glycine an amino acid?

Yes. It's one of the amino acids that make up protein.

Does glycine help you sleep?

It's an amino acid used to calm the nerves, so it may help with sleep. It's usually added on top of basic sleep supplements like magnesium when insomnia is severe.

Which is better, glycine or GABA?

Both are calming, but glycine tends to have fewer side effects, so it's an easier first thing to try.

Is it good to take glycine with NAC?

Yes. Both are raw materials for glutathione, so they're a popular combination. Some experts say it works better than taking glutathione directly.

What does glycine powder taste like?

It tastes sweet, so it's easy to mix into water or a drink. You can also mix it with inulin powder.

Related concerns

Trouble sleepingStress & anxietyHealthy aging & antioxidants

Last updated 2026-10-12