Hi Ashley,
This is a great question. I am not entirely sure why castor oil is not talked about in the course however it could be because it is not as versatile and all around ‘safe’ as the oils and fats that are discussed in the course.
Externally castor oil can be safe and very useful for certain applications, especially for muscles. Internally it can cause irritation and diarrhea.
I hope that helps a bit.
Warmly,
Benna