Effects of testosterone therapy

With a relatively short period of time (usually twelve months or less), testosterone treatment can cause visible, reversible and irreversible male secondary sexual development.

Depending on your age, genetics and general health as well as the dosage and method of testosterone delivery, there is some variability in the following effects.

Acne can occur – in some cases with a vengeance. Some men see a dermatologist and are prescribed strong medication to reduce their acne. Other guys ‘bear with it’ and in time as your hormones settle down, the acne does as well.

Acne results in up to 40% of individuals, mainly showing up on your back, which is similar cases of hypogonadal men who start androgen treatment past the age of normal puberty.

As testosterone begins to act on your body, your oil glands become more active and hair follicles are stimulated and begin to respond to the testosterone. Some people can get what looks like a short-term rash, which is part of the adjustment to testosterone.

Body Shape
Over time, the female pattern of carrying body fat on your hips, buttocks and upper thighs moves to that of the male pattern where body fat usually accumulates around your mid-torso.

People who stop taking their testosterone medication for whatever reason, can find their body fat pattern reverts to their hips, buttocks and upper thighs (female pattern) again. Others find this body fat remains on their mid-torso and they also accumulate body fat around the hips, buttocks and upper thighs.

These do not change dramatically. Overall, the bones of your skull, hands, feet, chest and hips do not alter.

As long you keep taking testosterone, it will maintain your bone mineral density and protect against osteoporosis. Studies show an increase in cortical thickness and density of the bone, which suggests an anabolic effect of the testosterone on the bones.

There are anecdotal reports from people who started testosterone after puberty, of an increase in shoe size or other unexpected growth spurts. These changes are more likely due to ligament tissue growth around your joints, as your bones become heavier because of the growth of muscles attached to your bones. (see Will I grow taller on testosterone?).

The main concern for all men and women as they age, is the risk of osteoporosis. Osteoporosis is a gradual thinning of bone-mass, which can eventually lead to fragile bones. Bones are assisted by a calcium rich diet, regular exercise and not smoking

There can be an initial reduction of breast fat as your body fat moves to the male body fat pattern. This can feel like the breasts have reduced in size, but this is only an effect of your body fat redistribution. Breasts do not significantly alter due to hormone therapy.

The fuller breast tends to become more pendulous while the smaller breast will become less firm, however they won’t disappear from your body with testosterone treatment.

Some people report mood swings either when they begin hormone treatment or during treatment. Two of the most common changes are a lower anger threshold and an increase in libido (sexual urge or desire).

If you become moody on testosterone sometimes this can indicate an adjustment (increase) of the dose is necessary. See your doctor as soon as possible if this happens. Blood tests comparing your testosterone levels with the average male testosterone range will show if this is the case.

Beginning testosterone therapy is an exciting time, bringing a mixture of emotions, both positive and negative as you interact with workmates, family and friends during transition. It’s also a strange new time; aches, pains, muscle tinges, changes, low energy, high energy, moodiness, funny feelings and all (know any teenagers?)

Facial and Body Hair
[This effect is permanent] The development of facial hair largely depends on your biological family traits, ethnic origin and genetic makeup. It also depends on your maintenance dose of testosterone.

Hair development follows that observed in boys going through puberty – the upper lip, the cheeks and the chin and so on.

Your biological male relatives’ facial hair pattern and growth will give you some indication of facial hair you’re likely to develop after several years on treatment.

[This effect is permanent] Your ovaries will eventually stop working and atrophy, resulting in permanent sterility. Menstruation usually stops after three months of testosterone treatment and almost all men will lose all menstrual function by around six months of treatment. If menstruation has not ceased within five months of testosterone therapy it is important for you to tell your doctors.

Many individuals report brief ‘hot flushes’ (in the first few months of treatment) similar to menopause symptoms. Usually, around this time, your ovaries will no longer be producing effective quantities of oestrogen (female) hormones. Fertility changes will differ from person to person, so any fertility questions or concerns should be addressed before you begin treatment.

Changes in your ovaries usually occur, which are indistinguishable from polycystic ovaries.

[This effect is permanent] Amongst the first noticeable changes is clitoral enlargement. The degree of growth depends, as with most of these changes, on your genetic disposition. There are reports of lengths of between three to six cm when erect and an increase in sensitivity. In 5-8% of men, the size becomes sufficient for penetration with a female partner.

If receptive intercourse is part of your sexual behaviour, vaginal intercourse might become difficult and painful as your vaginal tissues become drier, less flexible and more fragile. Some people no longer produce significant natural lubrication and will need to use a water based lubricant for intercourse. If an unexpected blood loss occurs from your vagina at any time, you should immediately report this to your treating doctor without delay.

Libido (Sex drive)
Some individuals report an increase in libido when starting testosterone treatment. Others report a decrease and others notice no change. Some men report a fluctuation in sexual attraction and many experience a phase of wondering if their sexual orientation is changing.

Testosterone doesn’t change your sexual orientation. Testosterone can help you feel more comfortable in your body and you can feel better exploring more of your sexual behaviour.

Male Pattern Baldness
[This effect is permanent] If your older male biological relatives are bald, there is a high likelihood this will affect you after several years of treatment. Up to 50% of men treated with testosterone develop male pattern baldness.

It is suggested, baldness can usually be predicted from the degree and pattern in uncles on your biological mother’s side of the family. Given baldness is linked to the X chromosome and most female-to-male men possess two of these, this trait is not reliably predictable.

Metabolism changes
About 10% of individuals gain excess weight after beginning testosterone therapy. While studies report a reduction of subcutaneous fat (the layer of fat just under your skin) they also report an increase of abdominal fat storage.

Many men gain weight due to the increased muscle mass and subsequent calorie intake. Most men report an increase in their metabolic rate and appetite. Unless a conscious balance is maintained between exercise and food intake, weight gain is inevitable.

Some individuals have anecdotally reported metabolic-related changes such as an increase in energy, less sleep demands, slightly higher body temperature, and generally feeling more alert.

The effects of testosterone on your body are both androgenic (responsible for the development of male sexual characteristics) and anabolic (helps to build and repair muscle tissue).

Anabolic effects mean that your muscles will develop according to the traits shown by your biological male relatives and enhanced by exercise you do.

Muscle mass, especially around your shoulders, neck and chest can increase with very little effort.

Skin Changes
As your oil and sweat glands become more active, changes occur in the skin of your face and body. These changes also increase your body’s ability to sweat. Odours tend to become less “sweet” or “musky” and more “tangy” or “metallic.”

If your skin was fairly oily to begin with, you might find it becomes oiler for a while until your testosterone treatment is stabilised. Some people had very dry skin before treatment and found testosterone improved the quality of their hair and skin.

[This effect is permanent] Testosterone will thicken your vocal cords causing a gradual lowering of the voice to the male range. Depending on your age and genetic factors, this usually occurs after six to twelve weeks of testosterone therapy.

Many men report this continuing over the following years. You will find you won’t be able to sing in the higher ranges like you might have been able to before treatment.

Other anecdotal effects
There are reports from some people who feel their way of thinking changed after starting testosterone.

Many men report a decrease in their ability to cry. Tears (or the lack of them!) seem to be less ‘on-tap’ than they might have once been.

There are reports of a decreased tendency to dwell on things. Many men report being more connected to their ability to ‘take action’ or their readiness to resolve issues. Some men have reported a reduction in sugary food cravings.

Others report an increased tendency to speak more directly as well as a lower tolerance for ambiguity and idle chatter in social situations.

Overall, men report an increased feeling of well being and a ‘calming down’ of their emotions. This ‘calming down’ of emotions is thought to be partly due to the increased satisfaction you have with your physical appearance as physical changes become evident to other people.

The effects of testosterone hormone treatment differ based on many factors: the age you start treatment, your general health, the dosage and frequency of testosterone, your use of recreational drugs, substance abuse, smoking, alcohol consumption and the use of antipsychotic medication.

Reversible effects

  • acne (especially in the first few years of therapy);
  • alterations in your blood lipids (cholesterol and triglycerides);
  • oestrogen production (reversible in early stages);
  • fertility cycle (reversible in early stages);
  • mild breast atrophy (due to loss of fat);
  • increased upper body strength and over-all muscle density;
  • male-pattern fat distribution throughout your body;
  • prominence of veins and coarser skin (depending on genetic traits).

Irreversible Effects (Permanent)

  • body hair development;
  • cessation of menstrual activity within three months for over 90% of individuals;
  • clitoral enlargement to varying degrees;
  • deepening of your voice.;
  • fertility cycle (irreversible over time);
  • increased facial hair, after the same pattern observed in pubertal boys;
  • male pattern baldness (if it runs in your family);
  • muscle development and conditioning (especially your upper body); and
  • oestrogen production ceases over time.