Understanding Your Sunscreen Ingredients

It's wonderful that you found a sunscreen you love and are interested in making your own! The list of ingredients you provided is very helpful in understanding what makes the product work. However, as mentioned before, replicating a cosmetic product exactly requires knowing the precise percentage of each ingredient and the specific manufacturing process, which are typically proprietary information.

Making sunscreen is particularly complex because the amount and type of UV filters (like Titanium Dioxide and Zinc Oxide) directly impact the SPF and PA protection level, which needs to be tested to ensure effectiveness and safety. The other ingredients work together to create the desired texture, stability, and feel on the skin.

Based on the ingredients you listed, here is a breakdown of their general functions in a cosmetic formulation, drawing from information about similar ingredients:

• Water: This is typically the base or solvent for the water-soluble ingredients and forms the continuous phase in an oil-in-water emulsion or the dispersed phase in a water-in-oil emulsion.
• Titanium Dioxide: A physical UV filter that protects against UVB and short-wave UVA rays by sitting on the skin's surface and scattering/reflecting UV light. Different particle sizes and coatings affect its transparency and ease of dispersion.
• Cyclomethicone / Cyclopentasiloxane: These are lightweight silicones that provide a silky, smooth feel to the skin. They help spread the product easily, reduce greasiness, and can evaporate quickly, contributing to a non-heavy finish. They are often used to disperse pigments like Titanium Dioxide and Zinc Oxide.
• C30-45 Alkyl cetearyl dimethicone crosspolymer: This is likely a silicone elastomer or crosspolymer. It acts as a thickener, provides a powdery or matte feel, helps stabilize emulsions, and can contribute to the product's texture and feel.
• Zinc oxide: Another physical UV filter, effective against both UVA and UVB rays, especially long-wave UVA. Like Titanium Dioxide, its particle size and coating influence its transparency and dispersion. Using both Titanium Dioxide and Zinc Oxide provides broad-spectrum UV protection.
• Methyl propanediol: A solvent and humectant. It helps dissolve other ingredients, enhances the absorption of active ingredients into the skin, and provides moisture.
• PEG/PPG-20/15 Dimethicone: A water-soluble silicone that acts as an emulsifier and conditioning agent. It helps mix oil and water components and provides a smooth feel.
• Hydrogenated polydecene: An emollient (softens and smooths skin) and a lightweight, stable oil that can act as a solvent or dispersant for other ingredients, similar to mineral oil but often preferred for its feel and stability.
• Talc powder: A mineral powder used as a texturizer, absorbent, or filler. In sunscreen or makeup, it can help reduce shine, improve feel, and aid in the spreadability of the product.
• Cetyl alcohol: A fatty alcohol used as a thickener, emulsifier stabilizer, and emollient. It helps give the cream body and a smooth feel.
• Panax gingseng root extract: A botanical extract known for potential skin benefits, such as antioxidant, anti-inflammatory, and potentially anti-aging properties. It falls under the category of "skin conditioning" ingredients.
• Methylparaben: A common preservative used to prevent the growth of bacteria, yeast, and mold in cosmetic products, ensuring product safety and shelf life.
• Triethanolamine: An alkaline ingredient used to adjust the pH of the formulation, particularly to neutralize ingredients like Carbomer to form a gel or thicken the product.
• Tocopheryl acetate: A stable form of Vitamin E, primarily used as an antioxidant to protect the formula from degradation. It can also offer some antioxidant benefits to the skin.
• Disodium EDTA: A chelating agent that binds to metal ions in water, preventing them from affecting the stability and appearance of the product.
• Carbomer: A gelling agent or thickener. When neutralized with an alkali like Triethanolamine, it forms a gel or increases the viscosity of the water phase, contributing to the cream's structure.

While understanding the function of each ingredient is a great starting point, formulating a stable, effective, and pleasant-to-use sunscreen requires careful balancing of all components and specific processing techniques. It is challenging to recreate a commercial product precisely at home.