THE SKIN DIET COMPANY Avocado Milky Glow Serum for Even Skin Tone with Hyaluronic Acid for Dull Skin

DESCRIPTION

What It Does: Attracts and retains moisture in the sc, improves skin barrier function at low concentrations, provides gentle keratolytic softening, and acts as a co-solvent for water-soluble actives.

Why It's Used: The reference humectant — lowest cost, best safety profile, universal formulation compatibility, and present naturally in the sc via lipase-mediated glycerolipid hydrolysis makes glycerin the industry standard against which all humectants are benchmarked.

How It Works: Three hydroxyl groups form 6 h-bonds with water molecules per glycerol unit — the highest oh-group density per carbon of any commercial humectant. glycerin also down-regulates epidermal serine proteases that overactivate in dry sc, improving desquamation and barrier integrity.

Typically Found In: All cosmetics,universal

TECHNICAL DETAILS

Primary Category: Functional ingredient – humectant

Secondary Functions: Tewl reduction,skin plumping

Application Areas:

Facial Skincare

Body Care

Hair Care

Beard Care

Color Cosmetics (Makeup)

Dietary/Oral Supplements

Typical Concentration Range: 1%–40%

SOURCING & ETHICS

Vegan Status: Yes

Halal Status: Yes

Source Notes: Synthetic or naturally derived. excellent aqueous solubility.

SKIN COMPATIBILITY

Irritancy Rating: 1/5 – very low

Comedogenicity Rating: 0/5 – non-comedogenic

Sensitivity Concerns: Non-irritating; suitable for all skin types.

Safe for Sensitive Skin: Yes

SAFETY & COMPATIBILITY

Safety Profile: Excellent safety profile. ewg score: 1.

Works Well With: Ceramides,emollients,occlusives,glycerin,hyaluronic acid

Avoid Combining With: No significant incompatibilities

SCIENTIFIC NOTE

Epidermal lipases hydrolyse sc glycerophospholipids during cornification, releasing glycerol that contributes to the natural nmf — topical glycerin directly supplements this endogenous sc humectant pool.

Last Verified: Cosing database,glycerin universal humectant review

Primary Sources: 2026-03-12

DESCRIPTION

What It Does: Provides collagen-specific hydroxyproline for triple-helix stability support and nmf conditioning.

Why It's Used: The collagen-specific nmf amino acid — hydroxyproline's almost exclusive occurrence in collagen makes it the most targeted amino acid for collagen-associated skin conditioning.

How It Works: 4-hydroxyproline provides inter-chain hydrogen bonding stabilising collagen triple-helix at body temperature. without hydroxyproline, collagen triple helix melts at 24°c (below body temperature). nmf component from hydroxyl group water binding. marker of collagen turnover — urinary hydroxyproline indicates collagen catabolism rate.

Typically Found In: Collagen-support products,nmf moisturisers,wound healing

TECHNICAL DETAILS

Primary Category: Active ingredient – collagen structural amino acid

Secondary Functions: Skin conditioning

Application Areas:

Facial Skincare

Body Care

Hair Care

Beard Care

Color Cosmetics (Makeup)

Dietary/Oral Supplements

Typical Concentration Range: 0.5%–5%

SOURCING & ETHICS

Vegan Status: Yes – synthetic or hydrolysis of gelatin

Halal Status: Conditional – from gelatin if animal-derived; synthetic vegan available

Source Notes: Commercially produced for cosmetic use. verify vegan/halal status with supplier.

SKIN COMPATIBILITY

Irritancy Rating: 1/5 – very low

Comedogenicity Rating: 0/5 – non-comedogenic

Sensitivity Concerns: Well-tolerated by most skin types.

Safe for Sensitive Skin: Yes

SAFETY & COMPATIBILITY

Safety Profile: Good safety profile at recommended concentrations. ewg score: 1–2.

Works Well With: Standard skincare actives

Avoid Combining With: No known significant incompatibilities

SCIENTIFIC NOTE

Hydroxyproline's role in collagen stability was definitively established through ramachandran's analysis of collagen triple helix geometry: the 4-hydroxyl group of hydroxyproline forms a water-mediated inter-strand hydrogen bond network that raises the triple-helix melting temperature from 24°c (without oh) to 37°c (with oh). this 13°c thermal stability gain from a single hydroxyl group is essential for collagen function at human body temperature.

Last Verified: Cosing database,bella et al. hydroxyproline collagen stability study,cir safety assessment

Primary Sources: 2026-03-12

DESCRIPTION

What It Does: Panthenol deeply moisturizes skin and hair, soothes irritation, accelerates wound healing, strengthens the skin barrier, and improves hair elasticity and shine.

Why It's Used: It is used because it is exceptionally versatile, working in both skin and hair formulations. it is gentle enough for sensitive and post-procedure skin, and converts to the active vitamin b5 within the skin.

How It Works: Panthenol penetrates skin and hair, where it is oxidized to pantothenic acid (vitamin b5), a coenzyme a precursor essential to metabolism. in skin, it acts as a humectant and stimulates fibroblast proliferation. in hair, it coats the shaft, improving manageability.

Typically Found In: Moisturizers,serums,toners,after-sun products,wound healing products,shampoos,conditioners,hair masks,beard care

TECHNICAL DETAILS

Primary Category: Active ingredient – provitamin b5

Secondary Functions: Anti-inflammatory,wound healing,hair conditioning

Application Areas:

Facial Skincare

Body Care

Hair Care

Beard Care

Color Cosmetics (Makeup)

Dietary/Oral Supplements

Typical Concentration Range: 0.5%–5% (typical: 1–3%)

SOURCING & ETHICS

Vegan Status: Yes – synthetically produced

Halal Status: Yes

Source Notes: Commercially synthesized. both d- and dl-forms used in cosmetics; d-panthenol is the biologically active isomer but dl-panthenol is less expensive and widely used.

SKIN COMPATIBILITY

Irritancy Rating: 1/5 – very low; one of the most soothing ingredients in cosmetics

Comedogenicity Rating: 0/5 – non-comedogenic

Sensitivity Concerns: Extremely rare contact allergy; considered one of the safest cosmetic ingredients. suitable for all skin types.

Safe for Sensitive Skin: Yes – ideal for sensitive, reactive, and post-procedure skin

SAFETY & COMPATIBILITY

Safety Profile: Exceptionally safe. ewg hazard score: 1. no significant concerns for irritation, sensitization, or systemic toxicity. safe during pregnancy.

Works Well With: Hyaluronic acid,ceramides,allantoin,niacinamide,centella asiatica,retinol (reduces irritation),glycerin

Avoid Combining With: No known significant incompatibilities

SCIENTIFIC NOTE

Panthenol has demonstrated wound-healing properties in clinical studies, stimulating fibroblast proliferation and migration. its dual humectant and anti-inflammatory action makes it particularly effective in barrier-repair formulations.

Last Verified: Cosing database,cir safety assessment,ebner et al. (2002) skin pharmacology and applied skin physiology

Primary Sources: 2026-03-12

DESCRIPTION

What It Does: Prevents microbial contamination and spoilage in cosmetic formulations.

Why It's Used: The benchmark cosmetic preservative – eu-permitted up to 1%, effective against virtually all cosmetically relevant microorganisms, and excellent tolerability.

How It Works: Phenol ring provides broad antimicrobial activity via disruption of bacterial and fungal cell membranes and inhibition of enzymatic activity. effective against gram-positive and gram-negative bacteria, yeasts (candida), and molds (aspergillus). activity ph range: 3-9.

Typically Found In: All cosmetic formulations as primary preservative

TECHNICAL DETAILS

Primary Category: Functional ingredient – broad-spectrum preservative

Secondary Functions: Skin conditioning

Application Areas:

Facial Skincare

Body Care

Hair Care

Beard Care

Color Cosmetics (Makeup)

Dietary/Oral Supplements

Typical Concentration Range: 0.1%–1% (eu max 1%)

SOURCING & ETHICS

Vegan Status: Yes – synthetic

Halal Status: Yes

Source Notes: Commercially produced for cosmetic use. verify vegan/halal status with supplier.

SKIN COMPATIBILITY

Irritancy Rating: 1/5 – very low

Comedogenicity Rating: 0/5 – non-comedogenic

Sensitivity Concerns: Well-tolerated by most skin types.

Safe for Sensitive Skin: Yes

SAFETY & COMPATIBILITY

Safety Profile: Eu cosmetics regulation max 1%. sccs assessed as safe at ≤1%. avoid use around eyes in baby products per some country regulations. ewg score: 4.

Works Well With: Standard skincare actives

Avoid Combining With: No known significant incompatibilities

SCIENTIFIC NOTE

Phenoxyethanol's widespread adoption as the primary cosmetic preservative followed the phaseout of parabens from many formulations in the 2000s-2010s. despite having a comparable or better safety profile to parabens, it is often cited in 'free-from' formulations – a consumer perception issue rather than a scientific safety concern.

Last Verified: Cosing database,sccs opinion on phenoxyethanol,cir safety assessment

Primary Sources: 2026-03-12

DESCRIPTION

What It Does: Provides hydroxyproline precursor collagen support and osmoprotective nmf conditioning.

Why It's Used: The collagen imino acid — proline and its hydroxylated form hydroxyproline comprise approximately 25% of all collagen amino acids, making l-proline the essential structural amino acid for topical collagen support.

How It Works: Hydroxylated by prolyl hydroxylase (requires vitamin c) to form hydroxyproline — essential for collagen triple-helix stability. nmf osmoprotective function via pyrrolidine ring water interaction. proline-rich repeats in collagen provide gly-pro-hyp triple-helix structure.

Typically Found In: Collagen-support products,nmf moisturisers,anti-aging formulas

TECHNICAL DETAILS

Primary Category: Active ingredient – collagen amino acid

Secondary Functions: Skin conditioning

Application Areas:

Facial Skincare

Body Care

Hair Care

Beard Care

Color Cosmetics (Makeup)

Dietary/Oral Supplements

Typical Concentration Range: 0.5%–5%

SOURCING & ETHICS

Vegan Status: Yes – fermentation

Halal Status: Yes

Source Notes: Commercially produced for cosmetic use. verify vegan/halal status with supplier.

SKIN COMPATIBILITY

Irritancy Rating: 1/5 – very low

Comedogenicity Rating: 0/5 – non-comedogenic

Sensitivity Concerns: Well-tolerated by most skin types.

Safe for Sensitive Skin: Yes

SAFETY & COMPATIBILITY

Safety Profile: Good safety profile at recommended concentrations. ewg score: 1–2.

Works Well With: Standard skincare actives

Avoid Combining With: No known significant incompatibilities

SCIENTIFIC NOTE

Proline's prolyl hydroxylase conversion to hydroxyproline is completely vitamin c-dependent: the hydroxylase enzyme requires ascorbate as cofactor. this biochemical interdependence explains why vitamin c deficiency (scurvy) produces defective collagen — hydroxyproline cannot form without vitamin c, and without hydroxyproline the collagen triple helix cannot maintain its structure at body temperature, causing tissue fragility.

Last Verified: Cosing database,cir safety assessment

Primary Sources: 2026-03-12

DESCRIPTION

What It Does: Provides endogenous-skin-identical emolliency with exceptional stability and skin compatibility.

Why It's Used: The most skin-compatible emollient – chemically identical to human sebum squalene component with outstanding tolerability across all skin types.

How It Works: Fully saturated hydrocarbon with zero oxidation sites provides exceptional stability unlike squalene's 6 double bonds. integrates into stratum corneum lipid bilayers with near-perfect biocompatibility. provides antioxidant protection to formulation via radical quenching.

Typically Found In: Facial oils,serums,non-comedogenic moisturizers,luxury body care

TECHNICAL DETAILS

Primary Category: Functional ingredient – emollient

Secondary Functions: Maximum biocompatibility,antioxidant stabilizer,non-comedogenic

Application Areas:

Facial Skincare

Body Care

Hair Care

Beard Care

Color Cosmetics (Makeup)

Dietary/Oral Supplements

Typical Concentration Range: 1%–100%

SOURCING & ETHICS

Vegan Status: Conditional – plant-derived (sugarcane, olive) preferred; shark liver-derived being phased out

Halal Status: Yes – plant-derived

Source Notes: Sustainable plant-derived squalane from sugarcane fermentation (amyris) or olive oil fractionation is preferred over shark liver-derived. chemically identical regardless of source.

SKIN COMPATIBILITY

Irritancy Rating: 1/5 – very low

Comedogenicity Rating: 0/5 – non-comedogenic

Sensitivity Concerns: Non-irritating.

Safe for Sensitive Skin: Yes

SAFETY & COMPATIBILITY

Safety Profile: Excellent safety profile. ewg score: 1.

Works Well With: Humectants,ceramides,actives as carrier

Avoid Combining With: No significant incompatibilities

SCIENTIFIC NOTE

Squalene constitutes approximately 12-15% of human sebum – the highest proportion of any skin lipid. topical squalane (stable, hydrogenated form) replenishes this abundant endogenous skin lipid. the complete absence of oxidizable double bonds (unlike squalene's 6 double bonds) eliminates the pro-oxidant concerns of natural squalene oxidation.

Last Verified: Cosing database,huang et al. squalane review,cir safety assessment

Primary Sources: 2026-03-12