Science
Mechanism of Action
Rosmarinic Acid exerts its effects through multiple pathways: it offers potent antioxidant protection by neutralizing free radicals and mitigating oxidative stress. Its anti-inflammatory action reduces redness and swelling by modulating inflammatory pathways and inhibiting pro-inflammatory enzymes (COX, 5-LOX) and cytokines. It also reinforces the skin barrier by promoting ceramide production, decreasing transepidermal water loss (TEWL), and activating NHE1 to lower skin surface pH. Furthermore, it possesses antimicrobial properties against specific bacteria and fungi relevant to acne, inhibits elastase to preserve elastin, stimulates collagen production, and exhibits a deglycating effect on AGE crosslink proteins, supporting skin firmness and elasticity while diminishing sebum production.
Research
Clinical Evidence
Medium confidence5%
Transparency
Dusting Analysis
The Formula
Formulation
Stability
Rosmarinic Acid is sensitive to light, heat, and oxygen. It demonstrates greater stability in acidic conditions; for example, its hydrolysis half-life is 26 years at pH 7 but only 2.6 years at pH 8, indicating rapid degradation at higher pH values. It is also more stable in hydroethanolic solutions compared to purely aqueous solutions. Encapsulation or co-formulation with other antioxidants is recommended to maintain efficacy and enhance absorption.
Synergies
- other antioxidants (for stability and absorption)
Conflicts
- strong acids (concurrent use may cause irritation)
- retinol (concurrent use may cause irritation)
Safety
Safety Profile
Rosmarinic Acid was included in a 2013 CIR safety assessment for Rosmarinus officinalis (rosemary)-derived ingredients, but a specific 'safe as used' or 'safe with restrictions' conclusion with a maximum concentration for cosmetic use of rosmarinic acid itself was not provided. However, rosemary extracts, which contain rosmarinic acid, have received Generally Recognized as Safe (GRAS) status from the US FDA for use as natural antioxidants in the food industry.
Your Skin
Skin Compatibility
Our Assessment
Verdict
Rosmarinic Acid is a valuable, multifaceted ingredient offering significant antioxidant, anti-inflammatory, and barrier-supporting benefits across all skin types, despite the current lack of a specific CIR safe-use concentration.
Related
Similar Ingredients
Finding similar ingredients…
References
Sources