Tamoxifen, as well as many medicines, can have an interaction with grapefruit and grapefruit juice. It is best to avoid grapefruit while on most medications as it can decrease or increase the effect of the drug. You should also avoid herbs and supplements like St. John’s Wort, turmeric, ephedra, country mallow, and cesium.

Remember, before taking a nutritional supplement or any natural product, talk with your doctor to make sure it won’t interact with Tamoxifen or any medicines you are currently taking.

Source:

Breastcancer.org, 2024. Tamoxifen.

Heery, M., 2023. Precautions for Patients Taking Tamoxifen and Aromatase Inhibitors.

Susan G. Komen, 2024. Turmeric. Drug interactions: Tamoxifen.