Does Soy foods Affect Black Cohosh?

Amount or timing may matter

The short answer

Both soy isoflavones and black cohosh modulate estrogen receptors. Combined use may cause unpredictable estrogenic effects.

How to arrange timing

Avoid taking black cohosh on the same day as heavy soy consumption, or consult a healthcare provider.

Reference

Reference noted for this food and supplement combination: Examine.com; Borrelli & Ernst, Eur J Clin Pharmacol 2008

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.