Glycerin is a naturally derived humectant—a ingredient that draws moisture from the air into your skin. It's one of the most widely used and well-studied moisturizing agents in skincare, helping skin feel softer and more hydrated.
Benefits
Attracts and retains moisture in the skin
Improves skin hydration and softness
Helps strengthen skin barrier function
Suitable for most skin types, including sensitive skin
Science: The Cosmetic Ingredient Review Expert Panel concluded glycerin is safe as used in cosmetics across all concentrations. Research shows glycerin effectively improves skin hydration and is well-tolerated with minimal irritation risk. It is also referenced in clinical guidelines for managing inflammatory skin conditions and maintaining skin integrity.
Tromethamine is a pH buffer and alkalizing agent used in skincare formulations to neutralize acids and maintain skin-friendly pH levels. It's not typically a featured active ingredient but rather a behind-the-scenes helper that stabilizes product formulations.
Benefits
Helps maintain optimal pH balance in skincare products
Stabilizes formulations containing acidic actives like retinoids or vitamin C
Allows safer delivery of potent ingredients without excess irritation
Potential concerns
Limited data on direct skin effects as a standalone ingredient
Generally used at low concentrations, minimizing irritation risk
May cause irritation if formulation pH becomes too alkaline
Science: The provided literature focuses on tromethamine's use as a pain-relief agent in ophthalmic settings rather than skincare applications. Limited peer-reviewed data is available specifically for its use in topical cosmetic formulations, though it is recognized as a safe, FDA-approved buffer agent in pharmaceutical and cosmetic products.
Propanediol is a lightweight humectant—a molecule that draws water into the skin to keep it hydrated. It's also used in cosmetic formulations as a solvent and preservative booster, helping products stay stable and feel smooth on the skin.
Benefits
Hydrates and moisturizes the skin
Improves product texture and spreadability
Helps preserve formulations naturally
Science: Propanediol can be produced through bio-based fermentation (from glycerol using microorganisms), making it an environmentally friendly alternative to traditional chemical synthesis. It is widely recognized as safe in cosmetic and food applications, with established use as both a humectant and preservative enhancer.
Panthenol is a lightweight humectant derived from pantothenic acid (vitamin B5) that draws moisture into the skin and helps maintain hydration. It also supports the skin barrier and can help soothe irritation, making it a popular choice in products designed for sensitive or compromised skin.
Benefits
Hydrates and moisturizes the skin
Helps calm and soothe irritated or sensitive skin
Supports skin barrier function and repair
Lightweight and non-greasy
Science: Panthenol is one of the few ingredients in sensitive skin formulations with clinical evidence specifically tested on volunteers with sensitive skin. Research confirms it reduces skin inflammation and supports barrier function, though comprehensive clinical studies on this ingredient remain limited compared to some alternatives.
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.
Polysorbate 60 is an emulsifier and solubilizer derived from sorbitan and polyethylene glycol. It helps blend water and oil-based ingredients together in formulations and can assist in delivering active ingredients into the skin.
Benefits
Helps stabilize product texture by mixing incompatible ingredients
May improve skin penetration of certain active ingredients
Enables creation of lightweight, uniform formulations
Science: Research shows polysorbate 60 functions effectively as a surfactant in nanoparticle delivery systems, enhancing skin penetration of topical actives. It has been used safely in pharmaceutical formulations with established stability profiles and minimal irritation potential at typical cosmetic concentrations.
2-Hexanediol is a humectant and preservative booster commonly used in skincare products to help retain moisture and extend shelf life. It works by drawing water into the skin while also enhancing the effectiveness of other preservatives, allowing brands to use lower amounts of traditional preservatives.
Benefits
Hydrates and moisturizes skin by drawing in water
Helps preserve products with lower preservative levels
Works synergistically with other skincare ingredients like niacinamide
Potential concerns
May cause cell viability concerns at concentrations above 1.0% in laboratory studies
Limited real-world safety data in humans at typical skincare concentrations (usually 2-5%)
Potential environmental concern if released into water systems
Science: While 2-hexanediol is widely used as a preservative substitute for parabens, recent cytotoxicity studies raise questions about safety at concentrations commonly found in skincare products (>2%). However, these findings are from laboratory cell studies and may not directly translate to human skin application. Further human safety studies are needed to confirm real-world risk.
Fragrance (Parfum) is a concentrated blend of aromatic compounds—including essential oils, aroma chemicals, and natural extracts—added to skincare products to provide a pleasant scent. It serves no active skincare benefit and is purely for sensory appeal.
Benefits
Enhances the sensory experience of using the product
Can make the skincare routine feel more luxurious or enjoyable
Potential concerns
May cause irritation or allergic contact dermatitis, especially in sensitive skin
Can trigger headaches or respiratory sensitivity in some people
Fragrance compounds may be comedogenic (pore-clogging) in acne-prone skin
Some fragrance components degrade over time and can become irritating
Science: Fragrance is a common cause of contact dermatitis and allergic reactions in skincare. The specific composition of 'Fragrance' blends is proprietary and undisclosed, making it difficult to identify which compounds may trigger individual sensitivities. People with sensitive or reactive skin often benefit from fragrance-free alternatives.
Polysorbate 80 is an emulsifier that helps mix oil and water-based ingredients together in skincare products. It's a synthetic compound derived from sorbitol (a sugar alcohol) and is widely used in cosmetics, pharmaceuticals, and food products to create stable, smooth textures.
Benefits
Enables smooth blending of oil and water ingredients
Improves product texture and spreadability
Helps stabilize formulations
Potential concerns
Rare but documented risk of allergic reactions or hypersensitivity in susceptible individuals, particularly those with sensitivities to polyethylene glycol (PEG) compounds
May cause contact dermatitis or irritation in people with sensitive skin
Science: Research indicates polysorbate 80 can trigger immediate hypersensitivity reactions in some individuals, with cross-reactivity possible with related compounds like polyethylene glycols. However, such reactions are uncommon in topical skincare applications compared to intravenous pharmaceutical use. The ingredient has a long history of safe use in cosmetics when applied to skin at typical concentrations.
Isohexadecane is a lightweight synthetic oil used in skincare formulations to improve texture, spreadability, and how products feel on skin. It helps emulsions stay stable and gives products a smooth, non-greasy finish.
Benefits
Creates a smooth, lightweight texture that spreads easily on skin
Helps skincare products absorb without a heavy or greasy feel
Improves product stability in emulsions
Science: Research shows isohexadecane is used in oil-in-water emulsions to enhance spreadability and skin feel. Studies confirm it functions effectively as an emollient ingredient, though it has slightly higher instability in nano-emulsion systems compared to linear-chain oils with similar carbon numbers.
Ceteareth-20 is a gentle emulsifier derived from natural plant oils and coconut. It helps bind water and oil together in creams and lotions, creating a smooth, stable texture that absorbs well into skin.
Benefits
Creates stable, smooth-textured formulations
Helps products absorb evenly into skin
Allows active ingredients to penetrate effectively
Science: Research shows that emulsifier choice, including ceteareth-20-containing systems, significantly affects how active ingredients like sunscreens penetrate and absorb into skin. The ingredient has a well-established safety profile in cosmetics and is widely used in dermatological formulations.
Homosalate is a chemical UV filter that absorbs UVB rays to protect skin from sun damage. It's commonly used in sunscreens and is often combined with other UV-blocking ingredients for broader protection.
Benefits
Absorbs UVB radiation to help prevent sunburn
Lightweight and works well in various sunscreen formulations
Allows for flexible product formats (lotions, sprays, etc.)
Potential concerns
Systemic absorption occurs—research shows it enters the bloodstream at levels exceeding FDA's 0.5 ng/mL threshold after a single application
Long-term effects of systemic absorption are not yet fully understood
May cause skin irritation or allergic contact dermatitis in sensitive individuals
Science: A 2020 FDA-led clinical trial found that homosalate, along with five other common sunscreen actives, is systemically absorbed and exceeds the FDA's recommended safety threshold (0.5 ng/mL) after a single application. While this absorption is documented, the clinical significance and long-term health implications remain under investigation.
Octocrylene is an organic UV filter that absorbs ultraviolet radiation, primarily UVB and short-wavelength UVA rays. It's commonly used in sunscreens and other cosmetic products to provide sun protection and prevent UV damage to skin and product formulations.
Benefits
Provides UVB and short-wavelength UVA sun protection
Works synergistically with other UV filters (notably stabilizes avobenzone)
Feels pleasant on skin, which encourages regular sunscreen use
Helps prevent skin cancer and UV-induced skin damage
Potential concerns
Potential allergic or photoallergic reactions in sensitive individuals
Concerns about possible endocrine system effects (currently under ongoing regulatory assessment)
Not a complete broad-spectrum protector on its own (limited UVA coverage)
Science: Recent research indicates octocrylene is stable and provides UV protection with minimal adverse effects compared to other organic filters like oxybenzone. However, potential endocrine concerns have been raised and the ingredient remains under continuous safety review by regulatory agencies including the European Chemical Agency.
