Seborrheic dermatitis and dandruff tend to overlap, you'll want to make use of the dandruff formulations. Be sure to avoid the dry scalp formulations as the ingredients in these will only exacerbate your SD symptoms! Students with seborrheic dermatitis or dandruff benefit from MCT oil, squalane or mineral oil. This means that if you make Shampoo A, you'll want to replace your olive oil with one of the aforementioned! I believe you can still make use of other oils suited for your porosity in conditioning recipes. Generally seborrhoeic dermatitis scalps should avoid the same ingredients as a dandruff scalp: - Fatty Acids and Oils (the safe options would be MCT Oil, Squalane and Mineral Oil) - Esters - Polysorbates - Cholesterol - Fatty Alcohols - Yeast Ferments - Squalene (different from Squalane) - Ceramides - Glycerin - Sugars - Neem Oil.