MCT Oil can leave the hair greasy, which is obviously not ideal! In the case of the student, it may be because her low porosity can't absorb any of the oil and therefore, it is just sitting on top of the strands. Therefore, there are a couple of things she can try - firstly, she can try making the formulation with a lower amount of MCT Oil than the Olive Oil in the original formulation -secondly, she can use something like Squalane instead, which is more suitable for low porosity hair due to how light weight it is 2. There are a couple of things to look out for when choosing a conditioner for low porosity hair: - firstly, consider what oils the conditioner contains, and how high up the list they are. Of course, low porosity hair suits sealing oils much better, therefore it is best to look for a conditioner that contains primarily sealing oils, over and above penetrating oils. This means that the oils higher up the list should be sealing oils, not penetrating oils. However if there are some penetrating oils nearer the bottom of the list, then that isn't so bad, since they are diluted within the whole formulation! - secondly, look to avoid protein ingredients within your shop bought conditioner. Some conditioners do contain things like soy protein or hydrolysed whet protein, which is not ideal for low porosity hair. So look for protein-free options!  Example: https://abeautifulworld.co.uk/collections/hair/products/feed-your-volume-conditioner 3. Many of the oils are covered in the Ultimate Guide to Hair Oils. We are working to improve this document so it covers more advice for medium porosity and contains some of the missing ingredients such as MCT oil or Shea Butter. In regards to Olive Oil and Castor Oil, these are both are seen as penetrating oils. Olive oil is closer on the spectrum to be able to suit more porosities, but it is seen to work best for high porosity hair!  Low porosity students can blend a couple of drops of penetrating oils with sealing oils, if they want to get some benefits from a penetrating oil but also want to make it work for their hair profile!