I've tried out the combo a few times but not enough to know what they do with each other, i need to try it again at some point. I do know though that Nigella Sativa is said to inhibit CYP2D6, and Harmalas are metabolized by CYP2D6 so it could potentiate and increase the dosage/duration of Harmalas possibly, depending on when the CYP inhibition is in effect and when you take the Harmalas.