GLYCINE

📋 Quick facts

Description: GLYCINE — amino acid, part of the skin natural moisturizing factor (NMF), soothing.

All Functions: amino acid, part of the skin natural moisturizing factor (NMF), soothing

Quick Facts:

• Category: humectant

Proven Benefits At A Glance:

• Glycine is one of three amino acids that make up more than half of collagen, the most abundant protein in your body
• Collagen provides structure and strength to skin, bones, cartilage, and blood vessels
• Your body can produce glycine from other amino acids, but may not make enough for optimal skin and connective tissue health
• A glycine-containing compound called 2-mercaptonicotinoyl glycine showed similar effectiveness to hydroquinone 4% for treating melasma with better tolerability

⚗️ Chemical Overview

Glycine appears as white crystals. (NTP, 1992) Glycine is the simplest (and the only achiral) proteinogenic amino acid, with a hydrogen atom as its side chain. It has a role as a neurotransmitter, a micronutrient, a nutraceutical, a hepatoprotective agent, an EC 2.1.2.1 (glycine hydroxymethyltransferase) inhibitor, a NMDA receptor agonist and a fundamental metabolite. It is a serine family amino acid, an alpha-amino acid and a proteinogenic amino acid. It is a conjugate base of a glycinium. It is a conjugate acid of a glycinate. It is a tautomer of a glycine zwitterion. A non-essential amino acid. It is found primarily in gelatin and silk fibroin and used therapeutically as a nutrient. It is also a fast inhibitory neurotransmitter.

Source(s): CAMEO Chemicals, DrugBank, ChEBI, via PubChem

📊 Comedogenicity

🛡️ Safety rating

Safety tier is a starting heuristic from regulatory status and comedogenic rating, not a dermatological verdict — see our Terms for the full disclaimer. Research confidence reflects how many real cited studies back this ingredient, not the strength of their findings.

🌍 Regulatory Status

💧 Skin Type Compatibility

⚠️ Don’t Combine With

📚 Research & Evidence

🔬 The Science

Glycine plays a structural role in your skin and body that’s worth understanding. #1: Glycine, along with proline and hydroxyproline, accounts for 57% of the total amino acids in collagen (Amino Acids, 2018). This matters because collagen is one-third of all protein in your body and is essential for maintaining the normal structure and strength of connective tissues—including your skin, bones, cartilage, and blood vessels. Your body can synthesize glycine from other amino acids like threonine, serine, and choline in a tissue-specific way (Amino Acids, 2018). #2: However, research indicates that your body’s own production of glycine may not be adequate for maximal collagen production (Amino Acids, 2018).

This is where dietary sources become relevant, though the research provided focuses mainly on animal studies and feed additives rather than human skincare applications. One consumer-facing application does appear in the research: #3: A skincare ingredient called 2-mercaptonicotinoyl glycine (marketed as Melasyl™), used in a facial serum at 0.5% concentration, demonstrated non-inferior efficacy to hydroquinone 4%—the gold standard treatment for melasma—while showing better tolerability with fewer local skin reactions (6.0% versus 21.4%) (Dermatol Ther (Heidelb), 2025). Both treatments improved melasma appearance significantly by day 28 of treatment. It’s important to note that the research on glycine itself for skincare is limited in these sources.

Most of the glycine research focuses on its role in collagen structure and its use in animal feed, not direct topical or oral human skincare applications. The melasma study uses a glycine-derived compound rather than glycine itself.

📄 Related Research

Matched by search — not necessarily verified support for every statement above.

• Li P et al. (2018). Roles of dietary glycine, proline, and hydroxyproline in collagen synthesis and animal growth. Amino Acids.
• Almaani N et al. (2011). Identical glycine substitution mutations in type VII collagen may underlie both dominant and recessive forms of dystrophic epidermolysis bullosa. Acta Derm Venereol.
• Butterfield RJ et al. (2013). Position of glycine substitutions in the triple helix of COL6A1, COL6A2, and COL6A3 is correlated with severity and mode of inheritance in collagen VI myopathies. Hum Mutat.
• Passeron T et al. (2025). Efficacy and Tolerability of a New Facial 2-Mercaptonicotinoyl Glycine-Containing Depigmenting Serum Versus Hydroquinone 4% over 3-Month Treatment of Facial Melasma. Dermatol Ther (Heidelb).
• Sung YY et al. (2025). Glycine soja Leaf and Stem Extract Ameliorates Atopic Dermatitis-like Skin Inflammation by Inhibiting JAK/STAT Signaling. Int J Mol Sci.

🧴 Products Containing GLYCINE

• Nivea Intimate Gel de toilette intime Apaisant Extrait de camomille, Panthenol & Acide lactique
• Nivea Intimate gel de toilette intime Douceur Huile de jojoba bio, Extrait de camomille & Acide lactique
• Nivea Sun kids Lait protecteur Protect & Sensitive
• Nivea Baby sun Crème solaire très haute protection FPS 50+
• Kneipp Pflegeölbad Mandelblüten Hautzart
• Kneipp Intensivbalsam 10 urea
• Kneipp 2 in 1 Dusche Lemongras Guarana
• Kneipp Sensitiv Handcreme Mandelöl
• tetesept tetesept Zeit für Dich
• Alverde Sensitiv After Shave Balsam
• alverde Naturkosmetik Repair Spülung strapaziertes & brüchiges Haar
• alverde Mamaglück Körperbutter Wilde Malve
• Alverde Rough Nature Bartserum
• Henkel, Schauma Sports Power-Shampoo
• Henkel, Schauma, Schwarzkopf & Henkel Frucht & Vitamin Shampoo
• Henkel, Schauma, Schwarzkopf & Henkel Himmlisch Lang, Langhaar Shampoo
• Always, Procter & Gamble Night Always sensitive
• Logona Nettoyant 3 en 1
• Lavera Anti-Schuppen-Schampoo
• Lavera Shampooing anti-pelliculaire
• Lavera Crème hydratante
• lavera Crème soft
• shampoo
• Lavera Soin En Profondeur Et Réparation 2 En 1 250 ML Lavera
• lavera Händchenhalten Handcreme
• lavera Straffende Nachtpflege
• Lavera Body Milk Sensitiv – Lavera
• Lavera, Lavera Naturkosmetik, Laverana Crème Basis Sensitiv
• lavera Festes Pflegeshampoo Frische & Balance – Bio-Matcha & Bio-Quinoa
• Glynt Derma Shampoo
• Daytox Daytox Cleansing Foam
• Cien VitalBeauty Dia
• alverde Après lotion mit mir
• Alverde Cremegel Hydro
• Alverde Körpercreme
• Henkel, Schwarzkopf, Barnängen Oil Intense
• Seba Med Seifenfreies Waschstück
• sebamed Flüssig-Wasch-Emulsion
• Alterra Hydro Tagescreme Bio-Traube & Bio-Weisser Tee
• Schaebens Feuchtigkeits Maske