Yes, you can mix vitamin C with your cream, but there are a few things to keep in mind. First, use less than a 4-to-1 ratio of vitamin C to your lotion or serum. This will help ensure that the vitamin C is effective and doesn't irritate your skin.
Second, it is crucial to understand that mixing vitamin C with certain ingredients can cause them to become less effective or even harmful. For example, it's recommended to avoid mixing vitamin C with AHAs/BHAs, retinol, and niacinamide, as these ingredients can interfere with vitamin C's pH levels and effectiveness.
However, mixing vitamin C with hyaluronic acid can be beneficial, as hyaluronic acid helps to hydrate the skin and improve the absorption of vitamin C.
Overall, mixing vitamin C with your cream can be a great way to boost your skin's health and radiance, but it's important to do so carefully and choose compatible ingredients.