A 34-year-old member asked:
Have there been any adverse interactions between femara (letrozole) and grapefuit?
2 doctor answers • 4 doctors weighed in

Dr. Barry Rosenanswered
General Surgery 35 years experience
Indirectly: There is a substance in grapefruit that disables the enzyme responsible for metabolizing estrogen in our bodies; therefore, eating grapefruit may increase the body's levels of estrogen. Femara (letrozole) is used to inhibit the production of estrogen in the body as a treatment for hormone-sensitive breast cancer. Therefore, eating grapefruit in these circumstances may counteract what you are treating.
6.3k viewsReviewed >2 years ago

A Verified Doctoranswered
41 years experience
Theoretically: There is a substance in grapefruit that disables the enzyme responsible for breaking down estrogen in our bodies; therefore, eating grapefruit could increase estrogen levels in the body. Femara (letrozole) is used to inhibit the production of estrogen in the body as a treatment for hormone-sensitive breast cancer. Therefore, eating grapefruit could work against what you are treating.
5.2k viewsReviewed >2 years ago
Last updated Jun 25, 2014
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