Glycine is classed as a non-essential amino acid because the body can synthesise it from serine. However, recent research suggests endogenous production may be insufficient to cover total metabolic needs, leading some scientists to reclassify it as “conditionally essential.” It plays roles ranging from collagen synthesis to neurotransmission, liver detoxification and creatine production.

Glycine is a building block of glutathione, the body’s main intracellular antioxidant, alongside cysteine and glutamic acid. Glutathione neutralises free radicals and helps conjugate toxins in the liver. Glycine also participates directly in Phase II liver conjugation reactions, binding to certain compounds to ease their elimination via the kidneys.

Glycine is found in protein-rich foods, most concentrated in collagen-rich sources: bone broth, chicken skin, pork skin, gelatin, and cuts with connective tissue. Plant sources include legumes, sesame seeds, pumpkin seeds and seaweed. Modern diets favouring lean muscle meat over collagen-rich cuts can fall short of optimal glycine intake, which is where supplementation can help.

Dissolve in a glass of water, fruit juice, or a warm drink — glycine has a naturally mild, pleasant taste. For sleep support, taking it in the evening, about 30 minutes before bed, is often recommended. At 3 g/day a 750 g pot lasts around 250 days; at 5 g/day, around five months.

Do not exceed the recommended daily dose. Not a substitute for a varied, balanced diet.

Can glycine help me sleep better?

Scientific studies suggest glycine taken before bed may support sleep quality for some people, likely by easing the drop in body temperature needed to fall asleep and modulating certain sleep-related neurotransmitters. It does not cause daytime drowsiness or dependency.

What does glycine powder taste like?

Glycine has a naturally mild, slightly sweet taste (its name comes from the Greek “glykys,” meaning sweet), making it easy to dissolve in everyday drinks with no bitterness.

Herba Barona is an independent specialist supplement shop in the heart of Paris — established in 2006. What you order is genuinely on our shelves: we ship from our own stock, with no dropshipping and no long waits.

Visit us at 10 rue Théophile Roussel, Paris 12 — or use Click & Collect and pick up your order in-store. We also deliver across France and Europe. Friendly, expert advice in English from our team.

Where is the shop?

Herba Barona is at 10 rue Théophile Roussel, 75012 Paris — a two-minute walk from Ledru-Rollin (line 8), close to Bastille. Open Tuesday to Saturday, 9:30 am–6:30 pm.

Can I order online or collect in store?

Yes. We ship across France and Europe under the same conditions as our French store, or choose Click & Collect to pick up your order for free at our Paris shop.