Gender Construction Kit Logo


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?

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?


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.


Re-using needles puts you at risk of infection.

If you’re taking this as an injection, it is important that you always use fresh needles. If you’re injecting yourself and you’re not sure where you can get fresh needles, look for a local needle exchange. These are organisations that will take used needles and replace them with fresh, sterile ones.

Used needles should be put into a dedicated sharps bin. This is a special type of bin for objects like needles and scalpels that makes it easier to dispose of them safely. You can bring the sharps bin to a needle exchange programme, some pharmacies, or your local council may offer a collection service. Make sure the bin is properly sealed before you try to take it anywhere.

If your injections are being done by a doctor or nurse, they should make sure the needles are sterile and dispose of them properly.

What should I be aware of?


Some brands of testosterone contain peanut oil.

Take care to read the ingredients in your medicine if you are allergic to peanuts.


Testosterone use can cause serious medical conditions including polycythaemia (too many red blood cells which can increase stroke risk) and liver problems 1, p.239.

To avoid serious side-effects, it is important to only use testosterone under medical supervision with regular blood testing.


Testosterone increases the risk of obstructive sleep apnoea (stopping breathing during sleep) which can lead to heart problems or sudden death.

Symptoms of sleep apnoea include:

  • very loud snoring
  • noisy and laboured breathing while you are asleep
  • stopping breathing followed by gasping or snorting

If you experience any of these symptoms, or you feel constantly tired or fall asleep during the day, speak to your GP. If you normally sleep in a room with someone else, you may wish to tell them the symptoms of sleep apnoea as you will not be awake to observe them.


Testosterone may cause infertility which may be permanent.

You should consider whether you need to use gamete storage (egg storage).


Testosterone usually causes periods to stop, but does not remove the risk of pregnancy 2. Do not use testosterone as a method of contraception 3, p.136.

Testosterone does not remove the need for cervical screening tests.


Do not take testosterone if you are pregnant as it can damage a developing foetus 4;2.

Why might I want testosterone?

Testosterone causes a large number of physical changes to your body that you may wish for, including significant changes to body fat distribution, hair growth, 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.

Why might I not want testosterone?

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.

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

How do I get testosterone?

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.

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 instead.

In the UK, some clinicians recommend that people taking testosterone long-term should have a hysterectomy. They theorise 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.

What kinds are there?

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 (transdermal testosterone) are rarely used in the UK (partly because of the frequency of bad reactions to patches) 5, p.37.

How much will it cost?

If you have received a formal diagnosis, the NHS will normally provide funding for testosterone therapy. Testosterone therapy is not usually provided to under-18s on the NHS, with the effects of hormones during puberty being stopped by GnRH agonists until the age of 18 when testosterone therapy can be commenced. Some services may additionally provide testosterone to selected 16 and 17 year old people 9.

Under some circumstances, it may be possible to get hormone therapy from the NHS without a diagnosis.

You do not have to pay the full cost of medication you are prescribed on the NHS. You are not asked to pay anything at all in Northern Ireland, Scotland and Wales. In England, people are asked to pay a small charge for each item on their prescriptions. There are ways you can reduce or avoid this cost, which you can read about on the NHS website.

If you are using private gender services, the service will normally ask your GP to write you NHS prescriptions. Your GP may or may not agree to do this - it is up to them. NHS England have published guidance for GPs to help them make this decision, which you may wish to give to your GP. If your GP agrees to prescribe, the cost of your medication is the same as any other NHS prescription. If your GP does not, the private service can write you private prescriptions, which you will have to pay the full cost of.


  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
  9. 9.
    NHS England Specialised Commissioning Team (2016) “Clinical Commissioning Policy: Prescribing of Cross-Sex Hormones as part of the Gender Identity Development Service for Children and Adolescents.” Link

Errors and omissions

Is there something missing from this page? Have you spotted something that isn't correct? Please tweet us or message us on Facebook to let us know, or file an issue on GitHub.