hmmmm Grape seed oil does not come from grapefruit, it comes from grapes.. grapefruit is a citrus fruit. compounds in grapefruit are very potent inhibitors of the CYP450 system, specifically CYP 3A4, inhibiting the metabolism of many drugs... there's actually research going on investigating the use of grapefruit to increase the potency of medications.... The anti-retroviral drug Ritonavir does the same thing....ther CYP450 inhibitors, pomegranate, cranberry, cinnamon, black/white pepper, ginger, nutmeg, etc..
grapfruit is a more potent CYP450 inhibitor than Ketoconazole as well which is an effective anti-androgen
Also FYI, Estradiol metabolism is mediated by the CYP450 isoforms CYP1A@ and CYP3A4, catalyzing the 16alpha-hydroxlation of Estradiol to Estriol..
And... the CYP450 system is responsible for the conversion of the hydroxytestosterones to testosterone...
so not only do they affect the metabolism of various drugs but also endogenous androgen levels
And I'd fully disclose any AAS use to my wife's Dr if that was something I was considering...