Modafinil and grapefruit

While grapefruit juice can help combat the induction that happens from modafinil, it does not seem to increase modafinil's effects. The same can be said of piperine, which is a much stronger CYP3A4 inhibitor. It may be slowing the metabolism down some. However, I have not noticed any significant difference in the strength or duration of modafinil while on it.

It does help with other drug interactions while on modafinil, though. Women on oral contraceptives in particular should look into it, as modafinil lowers their effectiveness by inducing CYP3A4.