Why do I feel so Tired after a Testosterone shot?

When you read the effects of low testosterone in the body, one of the most commonly listed symptoms is fatigue. Thus, testosterone has been linked with more energy, increased levels of alertness, stronger muscles and a better mood. However, this is a common oversimplification of very complex hormonal and metabolic mechanisms triggered by testosterone. There is much more to say about this hormone, and some people may experience unexpected side effects that may be opposed to what’s commonly expected, such as tiredness and fatigue.

Testosterone is a complex hormone that interacts with many different receptors and cells throughout the body. Thus, our understanding of this hormone should not be so linear, and there are four main reasons why testosterone replacement therapy might result in feeling tired, at least for a short while after receiving a shot.

Metabolic changes and tiredness

When talking about testosterone, there are two different metabolic states we should discuss: anabolism and catabolism. The former is based on creating new molecules and storing energy while the latter takes these molecules and breaks them down to release energy. That’s why testosterone as an anabolic steroid creates muscle mass and prevents the creation of energy by breaking down tissues.

Neither anabolism nor catabolism is good or bad. They should be correctly balanced to achieve proper body functions. An excess in catabolism depletes and wastes your energy sources, making you feel tired and contributing to the chronic fatigue syndrome. Similarly, an excess anabolism speeds up the creation of new molecules, spends a lot of energy in the process and may also lead to tiredness when you’re not providing your body with sufficient carbohydrates and protein.

Thus, a steroid shot may give you temporary symptoms of tiredness when you’re not following a diet accordingly or when the dose you’re administering is not appropriate for you.


Modifications in the brain neurotransmitters

The initial effect of testosterone modulates the brain neurotransmitters favouring the stimulation of the brain function and reducing the impact of various inhibitory neurotransmitters. Substances such as dopamine, serotonin and noradrenaline are activated, and their function becomes enhances while testosterone inhibits other neurotransmitters like GABA. This leads to a state of overexcitement and neurologic activation that may sometimes result in irritability, aggressive behaviour, and other abnormal psychologic states. There is also evidence Testosterone can improve brain functionality.

brain changes testosterone


In physiologic doses administered to patients requiring hormonal replacement, these symptoms may never show up. Conversely, when the dose is very high and not required for the normal function of the body, testosterone administration may result in anxiety, mood changes, fidgeting, and many other symptoms that contribute to burning more energy and contributing to exhaustion.

In this case, you may start feeling tired hours or days after receiving a testosterone shot. It is not immediate but a cumulative effect that should be fixed by adjusting the dose or examining whether you really need testosterone replacement therapy or not.

Testosterone and depression

Once again, we can’t assume anything with testosterone, and even if the hormone is commonly used to improve depression symptoms, it may also contribute to them. It is not common to find cases of depression associated with testosterone replacement therapy, but when it is used for athletic performance, it may become more common.

Testosterone and depression in aging men.

with thanks www.ncbi.nlm.nih.gov


According to studies, men with body-image concerns who start to use anabolic steroids usually become more concerned about their body and muscularity turns into a key aspect of their motivation and self-esteem. These testosterone users may be more susceptible to anxiety and depression than other groups and usually combine testosterone with many other body image drugs, including stimulants, beta-agonists, and additional hormones. All of these substances have been used and applied in medical conditions, but their effects in this type of individuals and in combination with anabolic steroids have not been thoroughly studied.

Chronic fatigue is a common complaint in patients with anxiety or depression. They usually feel very tired or with no energy to perform their day-to-day activities, and this severely affects their social, academic and working performance. In this case, the effect is not acutely felt after receiving testosterone. It is a chronic condition that develops over time and usually one or more psychological triggers associated with it.


Testosterone withdrawal syndrome

You have probably read about the withdrawal syndrome testosterone users experience after their hormonal cycles. Similar to alcohol and other drugs, chronic users who are not properly guided may become dependent on testosterone administration and experience drug cravings similar to those experienced by heavy alcohol users.

Among the most feared withdrawal symptoms, we can name depression, which is sometimes severe and leads to suicidal thoughts. Patients with a withdrawal syndrome are likely to develop mood swings, anxiety and restlessness, insomnia, loss of appetite, decreased sex drive, muscle pain, headaches, and extreme tiredness.

As a symptom included in the withdrawal syndrome, tiredness is marked and severe. It usually leads patients to continue using anabolic steroids and may be reported as a crippling and limiting factor. In this case, the symptoms start days after administrating testosterone for the last time and improves when using anabolic steroids once again.



If you’re experiencing a withdrawal syndrome, it is imperative to talk to your doctor and find out the right way to get over this phase. It will be necessary to perform a series of diagnostic tests as well to rule out other adverse effects of testosterone administration when it is not properly controlled, such as shrinking testicles and cardiovascular complications.




Celec, P., Ostatníková, D., & Hodosy, J. (2015). On the effects of testosterone on brain behavioral functions. Frontiers in neuroscience9, 12.

Kanayama, G., Hudson, J. I., & Pope Jr, H. G. (2008). Long-term psychiatric and medical consequences of anabolic–androgenic steroid abuse: a looming public health concern?. Drug and alcohol dependence98(1-2), 1-12.

Kanayama, G., Hudson, J. I., & Pope Jr, H. G. (2009). Features of men with anabolic-androgenic steroid dependence: a comparison with nondependent AAS users and with AAS nonusers. Drug and alcohol dependence102(1-3), 130-137.

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