What are the benefits of glycine for the body?

Glycine, an amino acid produced by the body

Glycine is a non-essential amino acid: it can be produced naturally by our bodies, unlike the so-called ‘essential’ amino acids, which must be supplied by the diet.

Glycine is synthesised from other compounds (such as serine) in the liver, kidneys and brain. It is also found in certain protein-rich foods, particularly animal products such as meat, bone broth, fish and gelatine.

Despite its chemical simplicity – it is the smallest of the amino acids – glycine is involved in a number of physiological processes, in particular those linked to the immune system, the nervous system and detoxification.

Although the body is able to produce glycine, its endogenous supply does not always cover all its needs. Glycine production also declines sharply with age... hence the importance of precisely targeting external intake of this amino acid.

What are the natural physiological functions of glycine?

Discreet but versatile, glycine is naturally produced by the body and acts on several levels.

Collagen synthesis

Glycine represents around a third of the amino acids present in collagen, the main structural protein in the skin, tendons, ligaments and cartilage.

It plays an active role in the formation and stability of collagen fibres (1), which are essential for tissue strength and elasticity.

This structural role explains why glycine is often promoted for its benefits to skin, hair and nails, as well as to joints and bone health.

Neurotransmission

Glycine also acts as an inhibitory neurotransmitter in the central nervous system.

It moderates neuronal activity, contributing to a balance between excitation and relaxation of the nervous system.

This mechanism partly explains why glycine may be associated with calming effects or contribute to better sleep quality (2).

Liver support and detoxification

Glycine is involved in the synthesis of glutathione, one of the body's major antioxidants.

Glutathione plays a crucial role in liver detoxification and cell protection against free radicals (3).

By participating in this process, glycine indirectly contributes to the proper functioning of the liver and the neutralisation of toxic substances from metabolism and the environment.

Immune modulation and antioxidant effect

A number of studies suggest that glycine may play a role in regulating inflammatory responses and the proper functioning of the immune system, in particular by acting on certain pro-inflammatory cytokines (4).

It also appears to be involved in protection against oxidative stress, thanks to its role in the synthesis of glutathione and other key compounds in cellular metabolism.

What are the potential benefits of glycine supplementation?

Although glycine is produced by the body, a great deal of research is looking into the potential impact of targeted supplementation (5).

Deep, restorative sleep

Several studies suggest that taking glycine before bed may help you fall asleep more quickly, improve the quality of deep sleep and reduce the feeling of tiredness when you wake up (6).

It is thought to act by slightly lowering core body temperature (a natural phenomenon that precedes sleep onset) and by modulating the activity of the parasympathetic nervous system.

These potential effects make it a gentle alternative to sedative drugs for people looking for natural sleep support.

Support for muscle recovery

The benefits of glycine supplementation are often mentioned in bodybuilding, particularly in terms of speeding up recovery after exercise and promoting the regeneration of muscle and connective tissue.

Its role in the synthesis of collagen and structural proteins makes it a strategic amino acid for regular physical activity.

Combined with a healthy lifestyle, glycine could help to reduce joint pain, improve tissue flexibility and support long-term physical performance (7).

Digestion and intestinal health

Supplementing with glycine could also support digestive health, thanks to its role in the production of digestive enzymes and the regulation of intestinal inflammation.

Some research indicates a potential impact on intestinal permeability, with better protection of the mucosa (8).

Glycine supplementation could therefore be of interest to people prone to functional intestinal disorders, among others.

Metabolic support and weight management

Glycine is also being studied for its possible effects on the assimilation of sugars and fats.

Some studies have reported improved insulin sensitivity and better glycaemic control following glycine supplementation, two key factors in the prevention of obesity (9).

It could therefore form part of an overall weight management strategy, although these results still need to be treated with caution.

Cellular ageing and skin health

Glycine is involved in collagen synthesis and may contribute to antioxidant defences, so it could play an interesting role in preventing skin aging and improving skin firmness and hair vitality.

Its indirect action on liver detoxification and cell repair reinforces this perspective. Supplementing with glycine could therefore support the body during episodes of chronic fatigue or oxidative stress.

How do you supplement with glycine?

Glycine is currently available as a dietary supplement in powder, capsule or tablet form.

Discover the Glycine powder dietary supplement, which provides an optimal intake of 2.5g of glycine per day.

To get the maximum benefits, it is advisable to follow the dosage indicated on the products and to seek advice from a health professional if you have a medical condition or are taking medication.

While research is increasingly exploring the benefits of glycine supplementation (particularly in terms of sleep, muscle recovery, digestion and skin), it should complement a healthy, balanced lifestyle.