Silybum marianum known commonly as milk thistle, is the plant that Silymarin, its extract rich in polyphenols and flavonolignans, comes from. Polyphenols and flavanols are specific antioxidants that also help to prevent the breakdown of collagen, elastin, and hyaluronic acid in skin. Silymarin is also known for its UVB-protective properties. Silymarin’s phenolic compounds show UV absorption in the UVB and shorter UVA wavelengths spectra, which means that it works synergistically in sunscreens to absorb UV rays before skin cells do.
Silymarin can prevent UVA-induced damage to skin cells by scavenging Reactive Oxygen Species (ROS) and inhibiting the inflammatory photoaging processes that degrade collagen and elastin, crucial parts of your skin’s moisture barrier. Its prevention of these photoaging reactions in skin also make Silymarin a soothing anti-inflammatory ingredient.
A., Joi. “Skin Photoprotection by Natural Polyphenols: Anti-Inflammatory, Anti-Oxidant and DNA Repair Mechanisms.” National Institutes of Health, National Institutes of Health, 20 Mar. 2023, https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2813915/.
He, Hailun. “Natural Components in Sunscreens: Topical Formulations with Sun Protection Factor (SPF) - PubMed.” National Institutes of Health, National Institutes of Health, 24 Dec. 2020, https://pubmed.ncbi.nlm.nih.gov/33360043/.
Vostálová, Jitka. “Skin Protective Activity of Silymarin and Its Flavonolignans.” National Institutes of Health, National Institutes of Health, 20 Mar. 2023, https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6470681/.