Glycine is the smallest of the protein-building amino acids, but also one of the most abundant in the human body. It makes up about a third of the amino acids in collagen, the main structural protein of skin, tendons, cartilage and bone. The body synthesises some of its own glycine, but dietary intake remains essential to cover needs that increase with age, intense physical activity or periods of stress. Glycine is naturally present in connective tissue and plays a role in several essential functions: sleep quality, collagen synthesis, muscle recovery and nervous balance.

Glycine has been studied for several years for its role in sleep quality. Taken in the evening, it acts as a mild inhibitory neurotransmitter that helps reduce neuronal excitation and supports falling asleep. Several studies suggest it may also improve the duration of deep sleep, a phase essential to cognitive and physical recovery. This gentle, non-sedating action makes it an interesting supplement for people who struggle to switch off at the end of the day, without the risk of next-morning drowsiness.

Collagen makes up nearly a third of all proteins in the human body, and its production relies heavily on three amino acids: glycine, proline and hydroxyproline. Supplementing with glycine can therefore support the body’s own collagen synthesis, particularly useful for people under joint strain or recovering soft tissue. It’s also a popular amino acid among athletes and those in convalescence, supporting the regeneration of tendons, ligaments and fascia. Natural collagen production gradually declines from age 25, which makes glycine intake relevant as part of an overall connective-tissue maintenance strategy — complementing regular consumption of bone broth, food-grade gelatine or collagen-rich cuts of meat.

The Nutrielement range stands out with a simple formulation: pure crystallised glycine encapsulated in a plant-based pullulan capsule (from fermented tapioca). No anti-caking agents, no colourings, no flavourings, no GMOs — a purity that supports digestive tolerance and suits vegetarian and vegan diets. The 400-capsule format offers the best value in the range, particularly suited to the long courses recommended with glycine to observe visible effects on sleep and recovery.

The usual dose recommended by Nutrielement is 6 capsules per day, providing about 5.1 g of pure glycine daily. These can be taken either in the evening with a meal to support sleep, or after training with a protein powder to support muscle recovery — with a large glass of water. For a sleep-focused course, a single evening dose 30-60 minutes before bed may be enough. Do not exceed the recommended daily dose.

Not recommended for pregnant or breastfeeding women, children and teenagers without medical advice. Seek professional advice if undergoing medical treatment.

How long before feeling effects on sleep?

Some people notice an improvement from the first doses, others feel the benefits after one to two weeks of regular use. Consistency matters more than dose for benefiting from effects on deep sleep quality.

Can glycine be combined with other sleep supplements?

Yes. Glycine combines well with magnesium bisglycinate (which already contains glycine), L-theanine, or plants like passionflower and lemon balm. For athletes, combining with BCAAs after training is also sensible.

How long does the 400-capsule format last?

At 6 capsules a day, a 400-capsule box lasts about 66 days, just over 2 months. At 3 capsules a day for light sleep support, the course can extend beyond 4 months.

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.