Does Grapefruit Affect Pregnenolone?

Amount or timing may matter

The short answer

Pregnenolone is a CYP3A4 substrate. Grapefruit may slow its metabolism, increasing downstream steroid hormone levels unpredictably.

How to arrange timing

Separate pregnenolone from grapefruit by at least 4 hours.

Reference

Reference noted for this food and supplement combination: Examine.com; Miller WL, Endocr Rev 2005

Important context

The effect can also change with food amount, supplement dose, product formulation, health conditions, and medication use. Ask a doctor or pharmacist first if you take medication, are pregnant or breastfeeding, or have a chronic condition.