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What is testosterone?

Hormone with many effects including muscle strengthening, hair growth, and lowering voice pitch.

It's also known as T, Testogel, Sustanon, or Nebido.

What does testosterone do?

The extent of the effects vary between people. Most people experience these effects:

Occasionally, people experience these effects:

Who can have testosterone?

  • You need to have had persistent dysphoria, but there is no specific time frame

  • You must have capacity to consent for this treatment

  • If you have significant medical conditions, these need to be “reasonably well-controlled”

  • You usually need to be at least 16

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

How long does testosterone last?

Many of the effects of testosterone are permanent and start within weeks. Changes may take several years to reach their full effect.

How do I stay safe?

  • Get regular blood tests

    Testosterone use can cause serious medical conditions. To reduce your risk level, use testosterone under medical supervision with regular blood testing.

  • Learn about sleep apnoea symptoms

    Testosterone users are more likely to have sleep apnoea. Learn about the symptoms to watch out for, and if you sleep in a room with someone else, you may wish to tell them too.

  • Use safe injection practices

    If your testosterone isn’t being injected for you by a nurse or doctor, read the safety information on our self-injection page.

What should I be aware of?

  • Testosterone is not a contraceptive

    You can still become pregnant while taking testosterone. You can read more about contraceptive options for people on testosterone on the FSRH website. If you become pregnant testosterone use must be stopped.

  • Testosterone may contain peanut oil

    Tell your doctor if you have an allergy to peanuts so they can choose a formulation of testosterone that does not contain peanut oil.

  • Testosterone use increases your risk of serious medical conditions

Using testosterone can increase your risks of polycythaemia (too many red blood cells which can increase stroke risk), liver problems 1, p.239, and obstructive sleep apnoea (stopping breathing during sleep which can lead to heart problems or sudden death). Testosterone does not remove the risk of pregnancy 2 and should not be used as a method of contraception 3, p.136. If you become pregnant, you should stop testosterone use, as it can damage a developing foetus 4;2.

Is testosterone right for me?

Testosterone causes a large number of physical changes to your body, including significant changes to body fat distribution, hair growth, and pitch of voice. Testosterone has noticeable effects on mood and thinking, and can increase energy and aggression, but can also help some people feel “more settled” in their body 1, p.239.

However, many effects of testosterone, such as changes to your voice or body hair, are permanent or not easily reversed. You might want some of the effects of testosterone, but not all of them, which may mean testosterone is not the right option for you. You can talk to your gender clinician if you would like to further discuss the possible effects.

Testosterone may cause acne. You can read more about acne and how to manage it on the NHS website.

While taking testosterone, you will still need to have cervical screening tests if you have a cervix.

How do I get testosterone?

Most people get testosterone using the UK system for gender medicine. Read our step-by-step guide to getting medical support for information about using that system. Some people also choose to access hormones without a medical diagnosis.

For testosterone therapy to begin, it is required that any other significant medical or mental health issues are “reasonably well controlled” 5, p.24. This means that a medical professional is currently helping or has helped you manage the condition.

What kinds of testosterone are there?

  • Short-acting injections

    Sustanon costs around £5-6 for 2-4 weeks

  • Long-acting injections

    Nebido costs around £100 for 3 months supply

  • Daily use gel

    Testogel costs around £50 for 2 months supply

Testosterone is commonly available as depot injections or as gels applied to the skin 1, p.241. Oral (pill) forms of testosterone are rarely used as blood testing is more complex, and patches are rarely used in the UK (partly because of the frequency of bad reactions to patches) 5, p.37.

What else might I want?

In a small proportion of people menstruation (periods) is not stopped by testosterone therapy, and either GnRH agonists 6, p.5 or progesterone 7 can be used to do this in addition to testosterone.

In the UK, some clinicians have in the past recommended that people taking testosterone long-term should have a hysterectomy. They theorised that as testosterone suppresses menstruation (periods), which could lead to endometrial hyperplasia (thickening of the lining of the womb), this might increase the risk of cancer 1, p.240. However, subsequent studies have not shown any evidence of an increased risk of reproductive cancers from testosterone use, and they do not suggest any need for hysterectomy 8. Hysterectomy for people taking testosterone is optional and you may feel the risks involved in a major operation are unnecessary. If you decide not to undergo hysterectomy it has been suggested that scans to check for thickening of the endometrium every two years could reduce any potential risks 1, p.240.


  1. 1.
    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
  2. 2.
    FSRH Clinical Effectiveness Unit (2017) “Contraceptive Choices and Sexual Health for Transgender and Non-binary People.” Link
  3. 3.
    De Roo, Chloe, Tilleman, Kelly and De Sutter, Petra (2017) “Fertility Options in Transgender People,” 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. 133–146. Link
  4. 4.
    World Professional Association for Transgender Health (2011) Standards of Care for the Health of Transsexual, Transgender, and Gender Nonconforming People, 7th Version, WPATH. Link
  5. 5.
    Royal College of Psychiatrists (2013) “Good practice guidelines for the assessment and treatment of adults with gender dysphoria.” Link
  6. 6.
    National Gender Identity Clinical Network for Scotland (2015) “Endocrine Management of Adult Transgender Patients.” Link
  7. 7.
    Seal, Leighton J (2007) “The practical management of hormonal treatment in adults with gender dysphoria,” in Barrett, J. (ed.), Transsexual and other disorders of gender identity: A practical guide to management, Radcliffe Publishing, pp. 157–190. Link
  8. 8.
    Toze, Michael (2018) “The risky womb and the unthinkability of the pregnant man: addressing trans masculine hysterectomy.” Feminism & Psychology, 28(2), pp. 194–211. Link

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