what is brain octane
Bulletproof Brain Octane vs XCT Oil Difference. Brain octane is a pure C8 oil (caprylic acid) compared to XCT oil, which is a blend of both C8 and C10 (capric acid). Both Bulletproof products are MCT (medium chain triglyceride) oils. If you follow the advice in the Bulletproof diet book you know how many recipes you can use it in.