OLAPLEX No.4 Bond Maintenance Strengthening and Reparative Hair Shampoo

DESCRIPTION

What It Does: Provides amino group-mediated preferential adsorption to damaged hair for targeted conditioning.

Why It's Used: Premium hair conditioning silicone – amino groups provide substantive adsorption to hair far exceeding pdms, with automatic targeting to the most damaged areas requiring conditioning.

How It Works: Amino (nh2) groups on silicone chain provide cationic character at normal ph, electrostatic adsorption to anionic hair surface. higher charge density at damaged sites increases adsorption where conditioning is most needed. si-o-si backbone provides permanent conditioning film with heat protection.

Typically Found In: Intensive conditioners,anti-frizz products,damage repair conditioners

TECHNICAL DETAILS

Primary Category: Functional ingredient – amino-functional silicone

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%–5%

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: 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

Amodimethicone's amino group-driven substantivity to damaged hair is dramatically greater than non-functionalized pdms. studies show amodimethicone deposits 50-200× more mass on bleach-damaged hair vs virgin hair, providing an automatic 'damage detection' conditioning system that directs the most conditioning to the hair areas that need it most.

Last Verified: Cosing database,robbins hair science,cir safety assessment

Primary Sources: 2026-03-12

DESCRIPTION

What It Does: Supports keratin production for stronger hair and nails.

Why It's Used: Hair and nail keratin infrastructure support; widely marketed despite evidence being primarily oral supplementation-based.

How It Works: Coenzyme for carboxylase enzymes essential for fatty acid synthesis and amino acid metabolism relevant to hair follicle function.

Typically Found In: Hair growth shampoos,nail treatments,multivitamin products

TECHNICAL DETAILS

Primary Category: Active ingredient – vitamin b7

Secondary Functions: Hair growth support,nail strengthening

Application Areas:

Facial Skincare

Body Care

Hair Care

Beard Care

Color Cosmetics (Makeup)

Dietary/Oral Supplements

Typical Concentration Range: 0.01%–0.5%

SOURCING & ETHICS

Vegan Status: Yes – synthetically produced

Halal Status: Yes

Source Notes: Synthetically produced for cosmetic use.

SKIN COMPATIBILITY

Irritancy Rating: 1/5 – very low

Comedogenicity Rating: 0/5 – non-comedogenic

Sensitivity Concerns: Non-irritating; excellent tolerability.

Safe for Sensitive Skin: Yes

SAFETY & COMPATIBILITY

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

Works Well With: Other b vitamins,niacinamide,antioxidant complexes

Avoid Combining With: No significant incompatibilities

SCIENTIFIC NOTE

Evidence for topical biotin efficacy in hair growth is limited – most clinical evidence comes from oral supplementation in biotin-deficient individuals.

Last Verified: Cosing database,cir safety assessment,patel et al. (2017) skin appendage disorders

Primary Sources: 2026-03-12

DESCRIPTION

What It Does: Provides antimicrobial skin conditioning with deodorant activity and preservation system enhancement.

Why It's Used: Multifunctional clean beauty preservation active — ethylhexylglycerin provides antimicrobial, deodorant, and skin conditioning in a single ingredient accepted in most natural cosmetic certification schemes.

How It Works: Glycerol ether provides antimicrobial via bacterial membrane phospholipid disruption. deodorant activity via reduction of underarm lipase enzyme activity (similar mechanism to triethyl citrate). skin conditioning from glycerol humectant component. synergistic with phenoxyethanol and diols.

Typically Found In: Natural preservation systems,deodorants,skin conditioning products

TECHNICAL DETAILS

Primary Category: Functional ingredient – antimicrobial glycerol ether

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%–0.5%

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: 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

Ethylhexylglycerin's deodorant mechanism is pharmacologically identical to triethyl citrate: both inhibit skin surface microbial lipase enzymes that convert odourless triglycerides to odorous free fatty acids. the glycerol ether structure of ethylhexylglycerin, combined with the 2-ethylhexyl chain, provides lipase inhibition similar to ester-based lipase inhibitors from a different chemical class.

Last Verified: Cosing database,schülke sensiva sc 10 technical data,cir safety assessment

Primary Sources: 2026-03-12

DESCRIPTION

What It Does: Delivers characteristic cosmetic function at recommended use concentration.

Why It's Used: Selected for functional contribution and formulation compatibility supported by cosmetic science and regulatory safety data.

How It Works: Works through the mechanism of its molecular class — physicochemical or biological interaction with skin proteins, lipids, or receptors as documented in peer-reviewed cosmetic literature.

Typically Found In: Skin care formulations

TECHNICAL DETAILS

Primary Category: Active ingredient – cosmetic active

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%–10%

SOURCING & ETHICS

Vegan Status: Conditional

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

Glycereth-26 has an established safety and efficacy profile within the cosmetic regulatory framework at standard use concentrations.

Last Verified: Cosing database,glycereth-26 technical literature

Primary Sources: 2026-03-12

DESCRIPTION

What It Does: Glycerin pulls water from the environment and deeper skin layers into the outer skin layer (epidermis), boosting moisture levels and keeping skin soft, smooth, and plump.

Why It's Used: It is used in virtually every moisturizer, serum, and cleanser because it is highly effective at hydrating skin, is well-tolerated by all skin types, and enhances the texture and spreadability of formulations.

How It Works: As a humectant, glycerin forms hydrogen bonds with water molecules, trapping them in the skin. it also reinforces the skin barrier by integrating into lipid structures between skin cells.

Typically Found In: Moisturizers,serums,cleansers,toners,sheet masks,sunscreens,body lotions,shampoos,conditioners

TECHNICAL DETAILS

Primary Category: Humectant

Secondary Functions: Skin barrier support,emollient,solvent

Application Areas:

Facial Skincare

Body Care

Hair Care

Beard Care

Color Cosmetics (Makeup)

Dietary/Oral Supplements

Typical Concentration Range: 1%–30% (typical: 3–10%)

SOURCING & ETHICS

Vegan Status: Yes – plant-derived (coconut, soy, palm) or synthetic

Halal Status: Yes – when plant-derived or synthetic; verify source with supplier

Source Notes: Derived from plant oils via hydrolysis or saponification; synthetic versions also available. palm-derived glycerin carries sustainability concerns.

SKIN COMPATIBILITY

Irritancy Rating: 1/5 – very low; non-irritating at all standard concentrations

Comedogenicity Rating: 0/5 – non-comedogenic

Sensitivity Concerns: Extremely rare allergic reactions; generally safe for all skin types including sensitive and baby skin

Safe for Sensitive Skin: Yes

SAFETY & COMPATIBILITY

Safety Profile: Widely recognized as safe. ewg hazard score: 1. no significant concerns for irritation, sensitization, or toxicity at typical concentrations (up to 50%).

Works Well With: Hyaluronic acid,ceramides,niacinamide,panthenol,urea,peptides,retinol,ahas/bhas

Avoid Combining With: No known incompatibilities at standard concentrations

SCIENTIFIC NOTE

Glycerin is an endogenous skin component found naturally in the stratum corneum. aquaporin-3 channels in keratinocytes facilitate glycerin transport, making it integral to natural skin hydration pathways.

Last Verified: Cosing database,cir safety assessment,ewg skin deep,inci decoder

Primary Sources: 2026-03-12

DESCRIPTION

What It Does: Glycerin pulls water from the environment and deeper skin layers into the outer skin layer (epidermis), boosting moisture levels and keeping skin soft, smooth, and plump.

Why It's Used: It is used in virtually every moisturizer, serum, and cleanser because it is highly effective at hydrating skin, is well-tolerated by all skin types, and enhances the texture and spreadability of formulations.

How It Works: As a humectant, glycerin forms hydrogen bonds with water molecules, trapping them in the skin. it also reinforces the skin barrier by integrating into lipid structures between skin cells.

Typically Found In: Moisturizers,serums,cleansers,toners,sheet masks,sunscreens,body lotions,shampoos,conditioners

TECHNICAL DETAILS

Primary Category: Humectant

Secondary Functions: Skin barrier support,emollient,solvent

Application Areas:

Facial Skincare

Body Care

Hair Care

Beard Care

Color Cosmetics (Makeup)

Dietary/Oral Supplements

Typical Concentration Range: 1%–30% (typical: 3–10%)

SOURCING & ETHICS

Vegan Status: Yes – plant-derived (coconut, soy, palm) or synthetic

Halal Status: Yes – when plant-derived or synthetic; verify source with supplier

Source Notes: Derived from plant oils via hydrolysis or saponification; synthetic versions also available. palm-derived glycerin carries sustainability concerns.

SKIN COMPATIBILITY

Irritancy Rating: 1/5 – very low; non-irritating at all standard concentrations

Comedogenicity Rating: 0/5 – non-comedogenic

Sensitivity Concerns: Extremely rare allergic reactions; generally safe for all skin types including sensitive and baby skin

Safe for Sensitive Skin: Yes

SAFETY & COMPATIBILITY

Safety Profile: Widely recognized as safe. ewg hazard score: 1. no significant concerns for irritation, sensitization, or toxicity at typical concentrations (up to 50%).

Works Well With: Hyaluronic acid,ceramides,niacinamide,panthenol,urea,peptides,retinol,ahas/bhas

Avoid Combining With: No known incompatibilities at standard concentrations

SCIENTIFIC NOTE

Glycerin is an endogenous skin component found naturally in the stratum corneum. aquaporin-3 channels in keratinocytes facilitate glycerin transport, making it integral to natural skin hydration pathways.

Last Verified: Cosing database,cir safety assessment,ewg skin deep,inci decoder

Primary Sources: 2026-03-12

DESCRIPTION

What It Does: Helps oil and water blend and can dissolve oily ingredients into water-based products.

Why It's Used: Hlb ~13 makes laureth-9 suitable for o/w emulsification and oil solubilization; widely used in cleansers and emulsions.

How It Works: 9 eo units give hlb ~13; c12 lauryl chain provides detergent activity; suitable for clear-phase oil solubilization and light o/w emulsification.

Typically Found In: Cleansers,o/w emulsions,oil solubilizers,toners

TECHNICAL DETAILS

Primary Category: Functional ingredient – emulsifier

Secondary Functions: Solubilizing,surfactant,cleansing

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: Conditional

Halal Status: Yes

Source Notes: Lauryl alcohol from coconut; eo from petrochemical; semi-natural.

SKIN COMPATIBILITY

Irritancy Rating: 1/5 – very low

Comedogenicity Rating: 1/5 – low

Sensitivity Concerns: Well tolerated. cir reviewed: safe as used.

Safe for Sensitive Skin: Yes

SAFETY & COMPATIBILITY

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

Works Well With: Anionic surfactants,amphoteric surfactants,humectants

Avoid Combining With: No significant incompatibilities

SCIENTIFIC NOTE

Laureth-9 (hlb ~13) is near the optimal hlb range for both emulsification and solubilization of vegetable oils; cas 3055-99-0 refers to the mixed-eo homologue distribution centered around 9 eo units.

Last Verified: Cosing database,inci dictionary,cir safety assessment lauryl ethoxylates

Primary Sources: 2026-03-27

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: 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: Provides film-forming conditioning and detangling with heat protection in a polymer that adsorbs substantively to hair.

Why It's Used: The most widely used cationic polymer conditioner – provides excellent conditioning and detangling while adsorbing strongly to damaged hair areas that need conditioning most.

How It Works: Cationic quaternary ammonium groups along the polymer backbone adsorb to anionic sites on hair keratin. higher charge density on damaged hair (more negative sites) leads to preferential adsorption where conditioning is needed. polymer film formation provides heat protection and volume.

Typically Found In: Shampoos,2-in-1 products,conditioners,styling products

TECHNICAL DETAILS

Primary Category: Functional ingredient – cationic polymer conditioner

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%–2%

SOURCING & ETHICS

Vegan Status: Yes – cellulose-derived

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

Polyquaternium-10's 'self-targeting' to damaged hair sites is a unique smart conditioning mechanism. as hair damage increases negative charge density by exposing keratin's aspartate and glutamate carboxylate groups, pq-10's cationic polymer backbone adsorbs preferentially to these high-charge damage sites – automatically delivering more conditioning where the hair needs it most.

Last Verified: Cosing database,robbins hair science,cir safety assessment

Primary Sources: 2026-03-12