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.
