Science
Mechanism of Action
Myrcene exerts its effects through multiple pathways, primarily acting as an anti-inflammatory agent by interfering with the production of pro-inflammatory cytokines, prostaglandins, and leukotrienes, and modulating enzymes like cyclooxygenase-2 (COX-2) and 5-lipoxygenase (5-LOX). As an antioxidant, it combats UVB-induced photoaging by reducing reactive oxygen species (ROS), diminishing the activity of matrix metalloproteinases (MMPs)-1 and -3, decreasing interleukin-6 (IL-6) levels, and promoting the synthesis of transforming growth factor type 1 (TGF-β1) and type I procollagen. Additionally, myrcene can transiently disrupt the stratum corneum's lipid organization, thereby improving the transdermal delivery of other beneficial compounds.
Research
Clinical Evidence
Medium confidence4%
Key findings
- 01 In vitro research demonstrated that myrcene (0.1-10 µM) ameliorated indicators of photoaging in UVB-irradiated human dermal fibroblasts, including a reduction in reactive oxygen species (ROS), matrix metalloproteinase (MMP)-1, MMP-3, and interleukin-6 (IL-6), alongside an increase in transforming growth factor type 1 (TGF-β1) and type I procollagen secretion.
- 02 A human patch test (n=25) confirmed myrcene to be neither irritating nor sensitizing at a 4% concentration.
Transparency
Dusting Analysis
Myrcene is classified under California's Proposition 65 as a chemical known to cause cancer or reproductive harm, necessitating warning labels for products exceeding specific thresholds within the state. While the U.S. FDA withdrew its authorization for myrcene as a synthetic flavoring in 2018, this action was stated to be unrelated to safety concerns under normal use conditions. Nonetheless, the Prop 65 listing is a significant regulatory flag for topical applications, requiring careful consideration and adherence to regional regulations.
The Formula
Formulation
Stability
Myrcene is highly susceptible to oxidation, which can compromise its efficacy and potentially lead to the formation of sensitizing byproducts. To extend shelf life and maintain ingredient integrity, stabilization with antioxidants (e.g., 0.05-0.1% rosemary extract in the oil phase) is essential. It must be stored cool, in a tightly sealed container, away from heat, open flames, sparks, and other ignition sources.
Synergies
- Enhances skin penetration of other active ingredients.
Conflicts
- Strong oxidizing agents
- Strong acids
- Strong bases
- Heat
- Open flames
- Ignition sources
Safety
Safety Profile
Beyond the potential for oxidation-induced sensitization, myrcene's listing under California's Proposition 65 as a reproductive toxicant and carcinogen is a critical safety consideration for its use in cosmetic products. The U.S. FDA's withdrawal of authorization for myrcene as a flavoring substance, although unrelated to normal use safety, signals broader regulatory scrutiny. Careful formulation, including antioxidant stabilization, and thorough risk assessment are paramount for its inclusion in skincare. While a 4% concentration was deemed non-sensitizing in a human patch test, undiluted β-myrcene has shown moderate irritation to rabbit skin, and Safety Data Sheets (SDS) indicate potential for skin and serious eye irritation. Individual sensitivities may also lead to irritation or allergic reactions with topical use.
Your Skin
Skin Compatibility
Our Assessment
Verdict
Myrcene offers promising anti-photoaging and anti-inflammatory benefits, alongside penetration enhancement, but its classification under Proposition 65 and susceptibility to oxidation-induced sensitization present significant safety and formulation challenges.
Related
Similar Ingredients
Finding similar ingredients…
References
Sources