Glossary
An extract from the leaves of rosemary (Rosmarinus officinalis) rich in carnosic acid and carnosol, powerful antioxidant compounds. In skincare, rosemary extract serves dual purposes: as a natural antioxidant that protects product oils from rancidity, and as a topical antioxidant that helps protect skin from free radical damage.
Rosemary extract's antioxidant potency rivals that of synthetic antioxidants like BHT and BHA. The primary active compound, carnosic acid, is a diterpene that effectively neutralizes free radicals and prevents the oxidation of unsaturated fatty acids in oils and butters. This makes rosemary extract valuable both as a product stability ingredient and as a skin-active compound.
When added to natural skincare formulations, rosemary extract helps prevent the oils and butters from going rancid, extending shelf life without the need for synthetic preservatives. At the same time, the carnosic acid provides antioxidant protection to the skin upon application, offering a dual benefit that few ingredients match.
Rosemary extract and rosemary essential oil are different products with different properties. The extract is produced through solvent or CO2 extraction and concentrates the polyphenol antioxidants (carnosic acid, carnosol, rosmarinic acid). The essential oil is steam-distilled and concentrates the volatile aromatic compounds (1,8-cineole, camphor, alpha-pinene).
In skincare products, rosemary extract is used for antioxidant protection, while rosemary essential oil is used for fragrance and its stimulating, antimicrobial properties. Both are valuable but they serve different functions in a formulation.
Rosemary extract is an antioxidant, not an antimicrobial preservative. It prevents oil rancidity (oxidation) but does not kill bacteria or mold. In water-free products (where microbial growth is not a concern), rosemary extract provides all the preservation needed. In water-based products, it supplements but does not replace antimicrobial preservatives.
Rosemary extract is generally well-tolerated at cosmetic concentrations (0.02 to 0.5 percent). However, individuals sensitive to rosemary or other Lamiaceae family plants should patch test. The extract is less likely to cause irritation than rosemary essential oil.
Both are antioxidants, but they work through different mechanisms and complement each other. Vitamin E breaks free radical chain reactions in fats, while rosemary extract scavenges free radicals before chain reactions begin. Using both provides more comprehensive protection than either alone.
Keep Learning
Browse hundreds of terms covering honey, beekeeping, and natural skincare.