Bicalutamide

Bicalutamide is a tablet that blocks testosterone from acting on the body's cells, without lowering the amount of testosterone in the blood. It was developed for prostate cancer, and some prescribers use it as the [anti-androgen](/glossary/anti-androgen) in feminizing hormone therapy.

Where you'll meet it

In online discussion more than in guidelines. Some informed-consent clinics and individual prescribers offer it, often for people who did not get on with spironolactone or cyproterone, and it comes up in non-binary plans because it blocks rather than removes.

Why the blood test looks odd

Because it blocks the receptor rather than lowering production, testosterone on a blood test can stay in the typical male range, or even rise. That is expected, and it means the usual way of checking an anti-androgen is working does not apply. Prescribers judge it by physical changes and by estradiol levels instead.

What gets checked

Bicalutamide can, rarely, cause serious liver injury, so prescribers who use it usually check liver function before starting and regularly afterwards, especially in the first months. It also tends to cause breast growth on its own, which is wanted by some people and not by others.

The evidence

Most of what is known about it comes from prostate cancer treatment, at doses and in patients quite different from trans women. Studies in trans people are few and small, and the major guidelines do not list it as a standard option. That does not make it a bad choice; it means you should know you are on a less-studied path and ask your prescriber why they suggest it.

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