The sunscreen landscape in the US is transforming, with new FDA regulations paving the way for safer, more effective protection. But before I dive into the regulatory and scientific basis of this new filter approval, it’s worth taking a step back to understand the difference between sunscreen filters and why a new approval is so monumental.
To better understand the innovation Tinosorb S brings, it's helpful to compare it with zinc oxide, a staple in many US sunscreens, including all of Eleusia's current SPF products.
There is a lot of misleading information circulating online about mineral vs. chemical filters, as at the end of the day all of these ingredients are really chemical (even H2O aka water is technically a chemical), and what this means for your skin and overall health. Tinosorb S is a chemical (or organic) UV filter, which works by absorbing UV radiation and converting it into harmless heat energy that dissipates from the skin. This mechanism allows it to provide excellent broad-spectrum coverage, particularly excelling in long-wave UVA protection (up to 380 nm), while remaining photostable - meaning it doesn't break down easily under sunlight, ensuring consistent efficacy over time. In contrast, zinc oxide is a mineral (or inorganic) filter that primarily reflects and scatters UV rays away from the skin, acting like a physical barrier. It's also broad-spectrum, offering solid defense against both UVA and UVB rays, and is renowned for its gentleness, as it sits on the skin's surface without penetrating deeply, making it ideal for sensitive skin types.
A key highlight is the anticipated approval of Tinosorb S (Bemotrizinol) by the end of 2025, a photostable UV filter widely used in Europe and Asia for over 20 years. The FDA’s 2025 deemed final order and proposed order, building on the 2020 CARES Act, aim to modernize the US market, which has been limited to only 16 approved UV filters since 1999, compared to 29 in Europe. Tinosorb S offers superior broad-spectrum protection against UVA rays—linked to skin aging and cancer—while boasting a robust safety profile, as noted in Regulatory Toxicology and Pharmacology (2001). Unlike older filters like oxybenzone, which a 2019 JAMA Dermatology study found absorbs into the bloodstream, Tinosorb S minimizes systemic absorption, making it a game-changer for microbiome-friendly brands like Eleusia that prioritize skin health and balance.
Key differences extend to safety, texture, and application. Tinosorb S has demonstrated low systemic absorption and minimal irritation in studies, addressing concerns with some older chemical filters that can disrupt hormones or harm marine life. Zinc oxide, however, is often praised as one of the safest options available, with no significant absorption into the bloodstream and a long history of use in baby products and for those with allergies. Aesthetically, Tinosorb S tends to be more cosmetically elegant, blending seamlessly into formulations without a visible white cast, which can sometimes be an issue with zinc oxide unless micronized or nano-sized particles are used. That said, zinc oxide's non-absorptive nature makes it a go-to for eco-conscious and microbiome-supportive products, as it avoids introducing potentially disruptive chemicals into the skin's ecosystem.
At Eleusia, we're committed to harnessing the best of science for balanced skin health. All of our SPF products currently rely exclusively on zinc oxide for its proven safety and efficacy in supporting the skin's natural barrier and microbiome. However, with the exciting potential approval of Tinosorb S, we're actively investigating its integration into our formulations. This could allow us to enhance broad-spectrum protection while maintaining our dedication to gentle, prebiotic-enriched skincare that nurtures your skin's unique ecosystem.
Weekly Ritual: Apply a broad-spectrum SPF 30+ sunscreen daily, reapplying every two hours during sun exposure.
