Phenoxyethanol is a preservative that prevents bacteria, yeast, and mold from growing in skincare products, helping them stay fresh and safe to use. It has been used safely in cosmetics for decades and is effective at very low concentrations.
Benefits
Prevents microbial contamination and product spoilage
Broad-spectrum antimicrobial activity against bacteria and yeast
Minimal impact on beneficial skin bacteria when used at approved levels
Potential concerns
Rare allergic contact dermatitis in sensitive individuals
May cause irritation if used in products at concentrations above 1%
Science: The European Scientific Committee on Consumer Safety considers phenoxyethanol safe for all consumers, including children, at concentrations up to 1%. Adverse effects observed in animal studies required exposure levels approximately 200 times higher than those in cosmetic products, and it is classified as one of the most well-tolerated preservatives in cosmetics.
Aspartic acid is a naturally occurring amino acid that plays a structural role in skin proteins and the extracellular matrix. In skincare products, it may be used to support skin firmness and resilience, though its primary function is typically as a pH buffer or humectant rather than an active anti-aging ingredient.
Benefits
Supports skin structure as a building block for proteins
May help maintain skin hydration as a humectant
Functions as a pH buffer in formulations
Science: Research indicates aspartic acid undergoes racemization (structural change) during skin aging and elastic fiber degradation, suggesting it plays a role in maintaining skin elasticity over time. However, peer-reviewed evidence for aspartic acid as a standalone active skincare ingredient is limited; most studies focus on its structural role in aging rather than its topical application benefits.
Alanine is a simple amino acid—a building block of proteins—used in skincare products to support skin hydration and provide conditioning benefits. It helps maintain the skin's natural moisture barrier and is generally used in small concentrations as part of formulation systems.
Benefits
Supports skin hydration and moisture retention
Helps condition and soften skin texture
May contribute to the skin's natural amino acid profile
Science: Limited peer-reviewed data available specifically for alanine in topical skincare applications. Alanine is a naturally occurring, non-essential amino acid that is well-tolerated by skin and widely recognized as safe in cosmetic formulations.
Glycine is a simple amino acid that serves as a building block for collagen, the protein responsible for skin structure and elasticity. In skincare, it helps support skin firmness and may contribute to anti-aging benefits when used as part of collagen-based formulations.
Benefits
Supports collagen production and skin structure
May help reduce the appearance of fine lines and wrinkles
Contributes to skin firmness and elasticity
Science: Research indicates that glycine, as a key amino acid in marine collagen supplements, plays a role in combating skin aging by supporting collagen integrity and minimizing oxidative stress. However, most anti-aging benefits are demonstrated when glycine is consumed as part of collagen peptides rather than applied topically alone.
Serine is a naturally occurring amino acid that your skin produces on its own. In skincare products, it helps support the skin's natural moisture barrier and may contribute to overall skin hydration and structure.
Benefits
Supports skin hydration and moisture retention
Helps maintain skin barrier function
May improve skin texture and smoothness
Science: Limited peer-reviewed data available for this ingredient in cosmetic skincare applications. Serine is a fundamental amino acid involved in skin biology, but the provided research focuses on disease mechanisms (fibrosis and pemphigus) rather than cosmetic benefits in healthy skin.
Valine is an amino acid—one of the building blocks your body uses to make proteins. In skincare products, it's included to help support skin structure and barrier function, though it's present in very small amounts compared to what you get from food.
Benefits
May support skin barrier integrity
Provides amino acid building blocks for skin proteins
Generally well-tolerated by sensitive skin
Science: Valine is a standard amino acid with an established safety record in cosmetics. The provided research focuses on prion disease diagnosis using valine polymorphisms as a genetic marker, which is unrelated to skincare efficacy. Limited direct evidence exists on valine's topical skincare benefits in peer-reviewed literature.
Isoleucine is an amino acid (a building block of proteins) that occurs naturally in the body and in foods. In skincare, it's included in formulations for its potential role in supporting skin structure and resilience, though it's typically present in small amounts.
Benefits
May support skin barrier function as part of amino acid profiles
Potential antioxidant properties when combined with other botanical compounds
Could contribute to skin firmness and elasticity through protein synthesis support
Science: Recent research identifies isoleucine as one of several salivary metabolites with potential relevance to skin health screening, and it appears as a minor component in botanical extracts studied for UV photoaging protection. However, direct evidence for isoleucine's independent efficacy in topical skincare products is limited.
Proline is an amino acid that serves as a building block for collagen, the protein responsible for skin firmness and structure. Your body uses proline (along with vitamin C) to create and repair collagen in the skin, which naturally declines with age.
Benefits
Supports collagen production and skin structure
May improve skin firmness and elasticity
Helps with skin repair and wound healing
Science: Proline is an essential amino acid in collagen synthesis; vitamin C-dependent hydroxylation of proline is a critical step in forming stable collagen. Limited direct human studies exist on topical proline alone, though it is recognized as a key structural component in skin biology and collagen formation.
Threonine is an amino acid that your body cannot produce on its own, so it must come from diet or skincare products. In skincare, it functions as a humectant and skin-conditioning agent, helping to attract and retain moisture in the skin.
Benefits
Helps maintain skin hydration and moisture balance
Supports skin barrier function as a natural amino acid
May improve skin texture and softness
Science: Limited peer-reviewed data available for threonine as a direct skincare ingredient. The provided research focuses on threonine as part of BRAF protein kinase pathways in melanoma treatment and fibrosis research, which are not relevant to topical cosmetic use. Threonine is generally recognized as safe in skincare applications.
Histidine is an amino acid that plays a key role in maintaining your skin's natural moisture barrier. In skincare, it supports the production of natural moisturizing factor (NMF)—compounds that help your skin retain water and stay hydrated.
Benefits
Supports skin hydration and moisture retention
Helps strengthen the skin barrier
May provide antioxidant protection through carnosine production
Science: Histidine is a naturally occurring amino acid essential for human health. Research shows it is a precursor to filaggrin breakdown products that form the skin's natural moisturizing factor, a critical component of skin hydration and barrier function.
Arginine is a naturally occurring amino acid that is a building block of proteins found in skin. In skincare products, it's used to support skin hydration and may help improve skin barrier function and elasticity.
Benefits
Supports natural skin hydration
Helps maintain skin barrier health
May improve skin firmness and elasticity
Science: Arginine is a naturally occurring amino acid in human skin with a strong safety profile. Research shows it is a normal metabolite excreted by skin and is used in clinical diagnostics, indicating its natural presence and compatibility with skin biology.
Ethylhexylglycerin is a preservative and antimicrobial ingredient used to prevent bacterial growth and extend shelf life in skincare products. It's a multifunctional ingredient that helps keep formulations stable and free from contamination.
Benefits
Prevents bacterial contamination in products
Helps extend product shelf life
Works synergistically with other preservatives for enhanced protection
Potential concerns
May not be effective against all bacterial species (notably some Pseudomonas aeruginosa strains)
Preservative-related sensitization possible in sensitive individuals, though uncommon
Science: Research shows ethylhexylglycerin has broad antimicrobial activity against many common cosmetic contaminants, though effectiveness varies by bacterial species. Studies demonstrate it can work synergistically with other preservative components to enhance biofilm inhibition.
Kiwi fruit extract is derived from the Actinidia chinensis plant and contains natural compounds like vitamins, antioxidants, and enzymes. In skincare, it's used for its potential to brighten skin, support gentle exfoliation, and provide antioxidant protection.
Benefits
Antioxidant protection from free radicals
May provide gentle enzymatic exfoliation
Potential brightening and skin-conditioning effects
Potential concerns
Possible irritation or allergic reactions in sensitive skin
Fruit extracts can increase photosensitivity in some individuals
Science: Limited peer-reviewed data available for this ingredient. Kiwi fruit contains vitamin C, polyphenols, and proteolytic enzymes that theoretically support skincare benefits, but clinical efficacy in cosmetic formulations has not been extensively documented.
Sodium hyaluronate is the salt form of hyaluronic acid, a naturally occurring substance found in your skin that acts like a moisture magnet. It can hold up to 1000 times its weight in water, making it excellent for hydrating and plumping the skin.
Benefits
Intense hydration and moisture retention
Reduces appearance of fine lines and wrinkles by plumping skin
Suitable for all skin types including sensitive and acne-prone skin
Science: Sodium hyaluronate is well-established in skincare research and has a strong safety profile with minimal irritation potential. Studies consistently demonstrate its effectiveness at improving skin hydration and elasticity when used in concentrations typical of consumer products.
Deionized water is purified water with minerals and ions removed, used as the main carrier and base ingredient in most skincare products. It helps dissolve and distribute active ingredients evenly throughout the formula.
Benefits
Hydrates and plumps the skin
Serves as a neutral base for other active ingredients
Helps maintain product texture and consistency
Science: Water is the most extensively studied cosmetic ingredient with a long history of safe use in skincare. Deionized water specifically minimizes mineral content that could interfere with product stability or efficacy.
