When making homemade skin care products, you need to choose ingredients carefully, as the wrong formula may cause skin irritation or other problems. Here are some common chemical ingredients that are widely used in skin care and are relatively safe, but it is still recommended to do a skin test before use, or consult a professional: 1. **Aqua**: As a solvent, water is the basis of most cosmetics and medicines. 2. **Glycerin**: A humectant that can help retain moisture in the skin and is suitable for dry skin. 3. **Hyaluronic Acid**: A powerful moisturizing ingredient that can attract moisture to retain moisture in the skin. 4. **Aloe Vera Extract**: It has soothing and moisturizing effects and is suitable for sensitive skin. 5. **Salicylic Acid**: Commonly used to treat acne, it has exfoliating and anti-inflammatory effects. 6. **Lactic Acid**: An alpha-hydroxy acid that is often used to exfoliate and improve skin texture. 7. Tea Tree Oil: It has antibacterial and anti-inflammatory properties, which is suitable for oily or acne-prone skin. 8. Glycolic Acid: A common exfoliant that helps improve skin smoothness and tone. 9. Ascorbic Acid: An antioxidant that helps brighten the skin and promote collagen production. 10. Tocopherol: An antioxidant that helps moisturize and protect the skin. Before using these ingredients, be sure to understand their concentration and applicable range, and do sufficient research. In addition, it is strongly recommended to consult a dermatologist or professional aesthetician before making any homemade skin products to ensure safety and effectiveness.