The other thing about Yohimbine HCL is that it should be taken in the absence of Carbs, or so I have read from a supp industry guy (Lobliner). Not sure if this applies to a topical application as well. As long as you adhere to the CNS protocol, you already have this aspect covered if training fasted/a.m. or on ULC days, just something to become/remain aware of on your CN or if you switch to another diet.