Authors: Dr Sav Zwickl & Elliot O’Donoghue
Content Warning: This article contains reference to genitalia, menstruation (periods), and sexual health. When referring to specific parts of the body, we use anatomical/medical terms e.g., clitoris, vaginal canal.
Note: Not all people want the same changes from using testosterone and not all bodies will respond the same to hormone therapy. All the body changes described in this article are typical but not universal. Lower doses of testosterone and lower levels of testosterone will likely impact the rate of changes, and whether some changes occur at all.
You can watch some videos showing the diversity of individual experiences at the bottom of this post.
What are the options for testosterone gender-affirming hormone therapy (GAHT) in Australia?
In our recent survey of nearly 500 trans and gender diverse people, Reandron was the most common choice for gender-affirming testosterone treatment in Australia (73.7% of survey respondents). Reandron is an intramuscular injection typically administered every 10 – 12 weeks to the buttock by a doctor or nurse. While the injections can be painful, Reandron is a popular choice given that besides a handful of injection appointments each year, it requires little thought or effort.
There are two other types of intramuscular testosterone injections available in Australia - Primoteston depot injections (used by 7.8% of our survey respondents) and Sustanon 250 injections (2.1%). Both these are typically administered every 2 – 3 weeks. Due to recent disruptions to supply and the greater frequency of injections, they are not as popular as Reandron.
For a variety of reasons, some people prefer to use a testosterone cream or gel, rather than injections. Testogel, an alcohol-based gel is currently the most common option (12.8%), followed by Androforte 5 cream (2.3%) and Testavan gel (2.1%). The gels and creams are typically applied to the body daily. This requires higher levels of compliance but also provides flexibility for those people using lower doses of testosterone and those who prefer to use it intermittently.
What changes can I expect once I start testosterone?
There are many changes that occur in the first three months of starting testosterone, as your testosterone levels rise, and your estrogen levels decrease.
On testosterone, your sex drive increases, and one of the first changes that people often report is to their genitals. Within weeks, some people notice an increase in the size of their clitoris and report it becomes more erect during arousal. It starts looking and behaving more like a penis. Within the trans community, this is often called ‘lower growth’ or ‘bottom growth’. You can read more about genital changes here.
Your body hair gets thicker and darker and there will be more of it on your legs, chest, back, and abdomen. Like in puberty, your skin will be oilier and acne prone. This acne may occur on the face, chest, and back. You will likely experience mood changes which will initially fluctuate with your testosterone levels between dosages. You will sweat more, and your overall body odour will change.
Your muscle mass and upper body strength will begin to increase and the fatty tissue around your hips and thighs will begin to redistribute to the stomach and waist. Weight fluctuation, particularly weight gain, may occur when taking testosterone.
During the first six months, your voice will crack and drop, although it may take a year or more before your voice finishes changing. During this time, most peoples’ menstrual periods tend to stop, however this does vary from person to person. For those with continued break-through periods, options for stopping bleeding may include increasing testosterone levels and progestin-based medications which can be administered orally or via intrauterine device.
Over the first year, facial hair growth will begin to occur, and like your newfound body hair, it will grow in thicker and darker than it had previously. If a person continually maintains testosterone use, some male-pattern balding may occur.
Not all of these changes are permanent. If you choose to discontinue testosterone use, any changes that have occurred regarding your facial hair, body hair, and any balding, deepened voice, and enlargement of clitoral tissue will be permanent. Many of the other changes you may experience are largely, if not entirely, reversible.
Typical changes on testosterone (varies from person-to-person)
Effect of testosterone
1-3 months after starting testosterone
1-6 months after starting testosterone
3-6 months after starting testosterone
1 year or more after starting testosterone
Typical changes from Testosterone, sourced from the Australian Informed Consent Standards of Care for Gender-Affirming Hormone Therapy (2022)
Are there any health risks or adverse effects of testosterone GAHT?
While there are many exciting changes to anticipate from taking testosterone, there are some risks or undesired effects to be aware of if you are considering starting hormone therapy.
Acne on the face, shoulders, and back is extremely common in those taking testosterone. The acne tends to be most severe at approximately 6 months and gradually improves over the next 1-2 years. Persistent issues with acne can be regulated with mild topical treatments (retinoids, benzoyl peroxide, antibiotics, anti-androgens), oral treatments such as antibiotics, spironolactone, and hormonal contraceptives or oral isotretinoin for more severe cases.
Balding is common amongst long-term testosterone users and will often reflect the hair loss patterns of the individual’s family. Any hair loss will usually begin after a few years on testosterone. For those who are uncomfortable with their balding, common treatments include topical minoxidil and oral finasteride.
Pelvic pain is also reported by some people using testosterone. Research suggests that increased pelvic floor muscle tone, rises and falls of estradiol and progesterone concentrations throughout the menstrual cycle in those whose periods have not stopped, and current or previous history of PTSD may all contribute to ongoing pelvic pain. Some treatment options are discussed here.
Some studies have suggested that taking testosterone aids bone density for those with sufficient hormone levels but can increase the risk of osteoporosis in those who have had their ovaries removed before the age of 45 without optimal hormone replacement. Individuals who have undergone an oophorectomy and are not taking testosterone or are doing so infrequently are at the greatest risk of losing bone density.
Some trans people develop Obstructive Sleep Apnea (OSA) with testosterone use. Both cisgender men and trans people using testosterone are susceptible to developing OSA. Changes to the physiology of the nasal passage, and fluctuating hormone levels over time are both likely causes. OSA can be treated by use of a respiratory ventilation machine, in combination with lifestyle changes and other therapeutic treatments.
High testosterone levels are commonly associated with high cholesterol and polycythemia - an increased number of red blood cells causing ‘thickened’ blood and high blood pressure. If left untreated, this can increase the risk of stroke, heart attack, cardiovascular disease and other conditions.
Research into whether trans people using testosterone have a higher risk of heart attack is inconclusive. For example, one study found that there may be a higher risk compared to cisgender women, but not cisgender men, while another study found no higher risk. Risk of heart disease can be minimised by monitoring blood pressure, glucose, and cholesterol, not smoking, engaging in exercise, and maintaining a healthy diet.
I have heard about ‘micro-dosing’. What does that mean?
The typical dose for each testosterone formulation is often referred to as a ‘full dose’. For most people, this dose will get them into the target ‘male’ testosterone blood level range for the fastest and most extensive body changes. Australian guidelines recommend a target trough level of 10–15 nmol/L.
While a majority of people use a typical or ‘full-dose’ of testosterone, our research indicates about one in ten people use a lower dose or intermittently use testosterone. These approaches are what are sometimes referred to as ‘micro-dosing’.
Lower doses and intermittent testosterone use typically result in lower testosterone levels than the ‘full- dose’, and although there will be body changes, they will occur at a slower rate. A lower dose and lower blood levels are often not effective at producing some changes, such as suppression of menstrual periods.
Where can I find more Australia-specific information?
Transhub provides more Australia-specific information about testosterone by and for trans people. The Position Statement on the Hormonal Management of Trans and Gender Diverse Individuals published in the Medical Journal of Australia (2019) and the AusPATH Australian Informed Consent Standards of Care for Gender-Affirming Hormone Therapy (2022) may also be of interest.
Ultimately, the decisions about testosterone formulation and dosage should be made between the trans person and their treating doctor and take into consideration gender-affirmation goals, barriers to compliance, medical history and potential risks of treatment. Sometimes trial and error may be needed to find the testosterone formulation that works best for you.
About the authors:
Dr Sav Zwickl (they/them) is a non-binary researcher and educator who is passionate about improving the health and wellbeing of the trans community through research. They have a Masters degree in Sexology, a PhD in Gender, Sexuality and Diversity Studies, and experience working in peer support roles with LGBTIQA+ young people and sexual health education. Sav has been part of the Trans Health Research team since early 2019.
Elliot O’Donoghue (he/him) is a transgender student and advocate who is outspoken about the intersection of trans/gender diverse identity with mental illnesses. He is currently studying to become a clinical psychologist with a specialisation in gender and eating disorders. Elliot is completing an internship with Trans Health Research.