Final answer:
Serums used in the Treat step usually have a higher level of inactive ingredients, such as antioxidants, ceramides, emulsifiers, and more. However, scientific evidence supporting the claims of these skin benefits is limited.
Step-by-step explanation:
When it comes to serums used in the Treat step, they typically have a higher level of inactive ingredients. These inactive ingredients often include antioxidants, ceramides, emulsifiers, fragrances, penetration enhancers, preservatives, and solvents. While some products claim to have anti-wrinkle and skin enhancement effects, it's important to note that scientific evidence supporting these claims is limited.