BHT (butylated hydroxytoluene) is a synthetic antioxidant used in skincare products to prevent oils and other ingredients from oxidizing and going rancid. It's used at very low concentrations (0.0002% to 0.5%) to extend shelf life.
Benefits
Prevents product degradation and extends shelf life
Keeps formulations stable over time
Allows use of beneficial oils without them spoiling
Potential concerns
Can cause skin irritation or allergic reactions in sensitive individuals at higher concentrations
May cause mild contact sensitization in some people
Minimal systemic absorption when applied to skin, but oral ingestion studies show potential liver and kidney effects at high doses
Science: The Cosmetic Ingredient Review Expert Panel concluded BHT is safe as used in cosmetic formulations at typical concentrations. When applied to skin, BHT remains largely in the skin with minimal systemic absorption, unlike oral exposure which showed some toxic effects in animal studies at high doses.
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.
Tocopheryl acetate is a stable form of vitamin E, an antioxidant that helps protect skin from damage caused by free radicals and environmental stress. It's the acetate ester of vitamin E, which means it's been chemically modified to be more shelf-stable in skincare formulas before being converted to active vitamin E in the body.
Benefits
Antioxidant protection against free radical damage
May help support skin barrier function
Contributes to maintaining skin hydration when used in moisturizers
Science: Tocopheryl acetate is a well-established vitamin E ester that the body converts to free vitamin E for use. Recent research shows it works effectively in moisturizing formulas, including those designed to support skin microbiome health in conditions like atopic dermatitis, though it functions as part of a broader skincare system rather than as an active ingredient on its own.
Phenoxyethanol is a preservative used in skincare products to prevent bacterial and fungal growth, keeping products safe and extending shelf life. It has been widely used in cosmetics for decades and works against a broad range of microorganisms.
Benefits
Prevents product spoilage and contamination
Allows products to remain safe for longer use
Effective against bacteria and yeast with minimal impact on healthy skin flora
Potential concerns
Very rarely causes allergic contact dermatitis in sensitive individuals
Some consumers prefer to avoid it due to personal preference, though safety data supports its use at approved concentrations
Science: European regulatory bodies have confirmed phenoxyethanol is safe for all consumers, including children, at concentrations up to 1% in cosmetic products. It is classified as one of the most well-tolerated preservatives in cosmetics, with allergic reactions being rare despite its widespread use.
Caprylic/Capric Triglyceride is a lightweight oil derived from coconut that acts as an emollient and carrier ingredient in skincare products. It helps soften the skin, improve product texture, and allows other active ingredients to penetrate more effectively.
Benefits
Improves skin hydration and reduces water loss from the skin
Creates a smooth, non-greasy feel on the skin
Helps deliver other active ingredients deeper into the skin
Supports the skin's natural moisture barrier
Science: Research shows that products containing 15% caprylic/capric triglyceride increase skin hydration and reduce transepidermal water loss (TEWL), likely through an occlusive moisturizing effect. The ingredient is also commonly used as an effective carrier oil in cosmetic formulations to enhance penetration of other skincare actives.
Citric acid is a naturally occurring organic acid commonly used in skincare products as an exfoliating agent and pH balancer. It belongs to a group of acids called alpha-hydroxy acids (AHAs) that work by gently removing dead skin cells from the surface to improve skin texture and appearance.
Benefits
Gentle chemical exfoliation to remove dead skin cells
Helps improve skin texture and reduce appearance of keratoses
Can help with acne-prone skin when used appropriately
Balances product pH
Potential concerns
May cause irritation, redness, or sensitivity, especially with frequent use or in sensitive skin
Can increase sun sensitivity — sunscreen use is recommended when using AHA products
Higher concentrations may cause stinging or dryness
Science: Citric acid is a well-established AHA used in cosmetic formulations for superficial skin peeling. Research indicates AHAs including citric acid have dual effects on skin and warrant caution regarding adverse reactions, particularly with concentration and frequency of use.
