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.
Limonene is a natural fragrance compound derived from citrus oils and other plants. It's used in skincare products primarily to provide a fresh, lemony scent and may also act as a preservative.
Benefits
Provides natural citrus fragrance
May help preserve products naturally
Sourced from plant-based ingredients
Potential concerns
Can cause skin irritation or allergic contact dermatitis in sensitive individuals
May penetrate skin and undergo metabolism in the liver; safety concerns noted for high-dose internal exposure in research
Can oxidize over time, potentially forming irritating compounds
Science: Limonene is widely used in cosmetics as a fragrance component from essential oils. However, research indicates monoterpenes like limonene can penetrate skin and be metabolized by the liver, with some hepatotoxic potential noted at high exposures—though typical cosmetic use levels are considered safe for topical application.
