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.
Glycerin is a naturally-derived humectant—a substance that draws water into the skin from the air and deeper skin layers. It's a common moisturizing ingredient used across skincare products to improve hydration and skin softness.
Benefits
Increases skin hydration by attracting moisture to the outer layers
Helps maintain skin barrier function and protects against dryness
Generally well-tolerated and suitable for most skin types, including sensitive skin
Science: A comprehensive safety assessment by the Cosmetic Ingredient Review Expert Panel concluded that glycerin is safe as used in cosmetics. Research supports its role as a humectant and skin conditioning agent, and it has been studied as part of broader skincare treatments for conditions like seborrheic dermatitis.
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.
Tocopherol is a form of vitamin E, a fat-soluble antioxidant that helps protect skin from damage caused by free radicals and oxidative stress. It works by neutralizing harmful molecules that can accelerate skin aging, particularly damage from UV exposure and environmental pollution.
Benefits
Protects skin from oxidative stress and free radical damage
Helps prevent premature aging and supports skin firmness
Works as a lipid antioxidant to protect skin's natural oils from degradation
May support skin barrier function
Potential concerns
Rare sensitivity or irritation in very sensitive skin types
Stability can be reduced when exposed to light and air — formulation quality matters
Science: Vitamin E (tocopherols) is recognized as a key natural defense mechanism against oxidative stress in aging skin, particularly against UV-induced damage. Research confirms it functions as a lipid-soluble antioxidant capable of preventing lipid peroxidation in skin cells, with α-tocopherol being the most biologically active form.
