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What is bicalutamide?

Medication that temporarily blocks the effects of testosterone.

It's also known as Casodex.

What does bicalutamide do?

  • Body hair

    Prevents additional growth and may reduce and thin

  • Facial hair

    Prevents additional growth and may reduce and thin

  • Muscles

    Weakens and makes smaller

  • Head hair

    Prevents some forms of hair loss

  • Fertility

    Causes temporary or permanent infertility

  • Lower body

    Causes genital shrinkage, reduces erections

  • Face

    Softens skin, reduces acne

  • Libido


  • Fragrance

    Prevents change of body odour due to puberty

Who can have bicalutamide?

  • This is not normally available on the NHS

  • You cannot have this if you are pregnant, or might become pregnant

  • You usually need to be at least 18

How long does bicalutamide last?

Bicalutamide is taken as daily pills and the effects stop if the medication is discontinued. Prolonged use may have some effects that are permanent and cannot be reversed.

What should I be aware of?


There are a number of health risks associated with hormone therapies. It’s important to get regular blood tests, both to spot problems before they arise and to make sure your dosage is correct.


The safety of bicalutamide is unstudied and unknown outside of cancer treatment 1.


Prolonged anti-androgen treatment can cause infertility, erectile dysfunction and genital shrinkage.


Taking anti-androgens without also taking another sex hormone (e.g. oestrogen and/or testosterone can cause osteoporosis.

Bicalutamide blocks the effects of testosterone, but does not reduce testosterone levels. Bicalutamide may also cause some increase in oestrogen levels, which can cause breast development 2;3.

Bicalutamide is an antiandrogen which is sometimes used outside of the UK. In the UK, endocrinologists usually prescribe GnRH agonists instead, as while bicalutamide is much cheaper to obtain, it is considered to potentially have higher risks of side effects 4, p.158. GnRH agonists are considered to have a very good side-effect profile 5.

Bicalutamide is not recommended for use by people under the age of 18, who are pregnant or could possibly become pregnant, or who are breastfeeding 6.

Are there other options?

Medications with similar effects whose side effects whose risks and side-effects are much better understood are GnRH agonists, spironolactone, and cyproterone.


  1. 1.
    Iwamoto, Sean J., Defreyne, Justine, Rothman, Micol S., Van Schuylenbergh, Judith, et al. (2019) “Health considerations for transgender women and remaining unknowns: a narrative review.” Therapeutic Advances in Endocrinology and Metabolism, 10, p. 2042018819871166. Link
  2. 2.
    Neyman, Anna, Fuqua, John S and Eugster, Erica A (2019) “Bicalutamide as an androgen blocker with secondary effect of promoting feminization in male-to-female transgender adolescents.” Journal of Adolescent Health, 64(4), pp. 544–546. Link
  3. 3.
    Angus, Lachlan M., Nolan, Brendan J., Zajac, Jeffrey D. and Cheung, Ada S. (n.d.) “A systematic review of antiandrogens and feminization in transgender women.” Clinical Endocrinology. Link
  4. 4.
    Vincent, Ben (2018) Transgender Health, Jessica Kingsley Publishers. Link
  5. 5.
    Seal, Leighton J (2017) “Hormone Treatment for Transgender Adults,” in Bouman, W. P. and Arcelus, J. (eds.), The Transgender Handbook: A Guide for Transgender People, Their Families and Professionals, Nova Science Publishers Inc, pp. 227–249. Link
  6. 6.
    Electronic Medicines Compendium (2020) “Bicalutamide 150 mg film-coated tablets.” Link


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