Bicalutamide and feminizing hormone therapy

Bicalutamide is an antiandrogen drug which means that it blocks the effect of androgenic hormones such as testosterone and DHT. The important thing to understand is that bicalutamide does not lower testosterone levels, it simply blocks the effect of testosterone on tissues.

In many cases, Testosterone levels initially increase after starting this medication however, that is nothing to be concerned about. Testosterone levels start declining over time, this change happens much more rapidly if you're also taking estrogen and progesterone in addition to bicalutamide.

Bicalutamide is most commonly used for treating men with prostate cancer

Offlabel uses:
Puberty blocker
Feminization therapy
Androgenic Alopecia in females
Acne Reduction

Today primarily will be focusing on bicalutamide use in transgender females
Other antiandrogen medications often prescribed are spironolactone and cyproterone acetate. However, these drugs are much weaker than bicalutamide. Cyproterone is also not available in the US.

Bicalutamide also helps the aromatization of testosterone to estrogen which is why it is especially helpful for breast development when compared to other antiandrogen medications. Some small studies have shown better breast growth when compared to Aldactone and cyproterone. A possible mechanism is that Aldactone causes early maturation of the breast bud when compared with bicalutamide.

Bicalutamide is known to cause a reduction in vitamin C levels and glutathione levels in animal studies. Taking glutathione and vitamin C may reduce the risk of liver toxicity however I have no data to support this strategy.
Key Benefits:
better Breast development when compared to spironolactone and Cyproterone.
Reduced acne
Reduce facial hair
Halflife is 6 days so the drug stays in the body for several days so only twice a weekly dose is adequate. Compare that to spironolactone which has a halflife of only 2 hours
Do not use or use caution if you
Have Liver problems
If you drink heavily
Over the age of 35
Get a liver panel done 24 weeks after starting the medication. For any sign of liver failure such as jaundice, the medication must be immediately stopped.
Dosing:
Bicalutamide stays in the body for several days and has a halflife of 6 days which means half of the drug is broken down and removed by the body in 6 days. Twice a weekly dose of 50 mg is adequate. Higher doses increase the risk of liver toxicity and should be avoided
In summary, this is a very good medication for feminization therapy especially if high breast growth is strongly desired. Liver toxicity is a major concern and can be lifethreatening so do not consume alcohol, and avoid hepatotoxic medications such as Tylenol.