There may be several reasons causing your scalp to itch after using your homemade shampoo. Find below the most common cases and our suggestion to improve: ** If you used shampoo A + dry scalp: The surfactant is too strong for your sensitive scalp, try shampoo B instead. ** If you used shampoo A + oily scalp: There may be too much oil on your scalp now, causing inflammation. Try switching the oil for an MCT oil or reducing the amount of oil in your shampoo. ** If you used shampoo B on an oily scalp: It probably is not cleaning enough so you should try either using coco-glucoside in the recipe or even switching for shampoo A all together. ** If you used shampoo B on a dry/sensitive scalp: This is the most gentle shampoo that you can find so you are probably sensitive to one of the ingredients. Try tweaking the recipe by changing one ingredient at a time to see if you can figure out which one you are sensitive to. We're all unique so there will be an infinite versions of the tweaks you can do to your shampoo. These are general guidelines to help you figure out the first tweaks you can try to your shampoo. You're doing a great job by paying attention to the way your hair and scalp respond to products. Listening to your body is key on your haircare journey!