The main hormone associated with male sex, testosterone, is necessary for many body processes. It controls your bone density, muscle mass, male sexual development, mood, and energy levels. In recent years, testosterone replacement therapy, or TRT, has become more and more used as a performance enhancer in addition to its primary use as a treatment for medical conditions brought on by low testosterone levels. 
Although it is generally known that testosterone has a significant impact on both your physical and mental health, what happens if the balance tips and you take too much testosterone? This worry is not merely theoretical or imaginative; several research investigations have been conducted in light of this question and looked into the effects of high testosterone injections, both therapeutically and athletically.
Side Effects of Injecting Too Much Testosterone
When commencing TRT, the recommended weekly dosage typically falls between 50 and 100 mg; this can be increased to 200 mg if necessary to reach the target testosterone levels. This dosage is intended to mimic the natural range of testosterone in the body, which in healthy men is normally between 300 and 1000 ng/dL.
A Study by Wilson et al. entitled, Concentration Matters for Testosterone-Induced Neurotoxicity, the study looked at the potential neurological effects of high testosterone injections. Studies in the lab suggest that concentrations exceeding 100 nanomoles (nmol) may have neurotoxic consequences; however, these high levels are uncommon in regular TRT and are usually associated with misuse of the hormone. Moreover, these in vitro studies, which are conducted outside of a living organism, often use testosterone levels that far exceed those found in human abuse cases. Their relevance to real-world physiology is thus questionable. 
In a nutshell, while this study hints at neurotoxic risks at extremely high levels of testosterone for a prolonged period of time, their applicability to humans, especially in medical contexts, is unclear, underscoring the need for more human-based research to understand the risks of high testosterone concentrations safely.
Can You Inject Too Much Testosterone?
When examining whether you can inject too much testosterone, it's important to compare the levels achievable through abuse with those used in therapy. Wilson indicates that the concentrations of testosterone reached through abuse (quantities of injecting 400cc or greater weekly in some cases) are significantly higher than those used in medical treatments. However, even in abuse scenarios, surpassing the extremely high levels used in some lab studies is unlikely.
Understanding the difference between total and free testosterone is also crucial. Total testosterone includes both bound and unbound (free) testosterone. Free testosterone, which is not bound to proteins like SHBG (sex hormone-binding globulin) and albumin, makes up only about 2–4% of the total circulating testosterone. Since a large portion of testosterone is bound and not readily available to certain tissues, including the brain, the actual impact of testosterone on these tissues can differ significantly from what in vitro studies suggest. 
If a patient injects high doses of testosterone for an extended period, it can cause certain physical manifestations.:
Male pattern baldness
Heart: Left ventricular hypertrophy, decreased ejection fraction
Testicular atrophy, Azoospermia
Kidney: decrease in eGFR and proteinuria
Men will often refer to cycling high doses of testosterone "off" and "on" to prevent the side effects of the anabolic steroids, as mentioned above. While cycling is not recommended for testosterone replacement, which is given continuously at a steady dose to achieve normal, elevated physiological levels of serum testosterone, some men push this to the extreme in cases where physique building is desired.
What Happens If You Inject Too Much Testosterone?
In the event that you do inject too much testosterone, higher than what our bodies are used to, several significant effects can occur, as illuminated by three studies. Each of these studies provides insights into different aspects of the impact of excessive testosterone use.
Effects on Spermatogenesis and Hormone Secretion
Matsumoto’s study focused on how chronic administration of testosterone affects spermatogenesis (the production of sperm) and hormone secretion. In this study, men were given varying doses of testosterone enanthate, ranging from physiological to supraphysiological (higher than normal) levels. The findings showed that at a dose of 50 mg per week, luteinizing hormone (LH) and follicle-stimulating hormone (FSH) levels, as well as sperm counts, were suppressed to about half of the control values. Interestingly, increasing the dose to 300 mg per week didn't result in a more pronounced suppression of LH, FSH, or sperm production compared to 100 mg per week. This indicates that there's a limit to how much testosterone can suppress these hormones and sperm production, suggesting that even higher doses may not lead to more significant suppression. 
Testosterone Dose-Response Relationships
Bhasin and colleagues conducted a study to understand how different doses of testosterone affect various body functions. They discovered that for certain aspects like sexual function, thinking skills related to space and orientation, and levels of PSA (a marker used to check prostate health), just a low dose of testosterone was sufficient. Increasing the testosterone dose didn't enhance these aspects any further.
On the other hand, when they increased the testosterone dose, they noticed significant changes in body composition and physical strength. Higher dosages resulted in an increase in muscle mass, size, and strength, notably in leg press activities. They also discovered changes in hemoglobin (a protein present in red blood cells), IGF-I (a growth hormone), and HDL cholesterol (the "good" cholesterol) levels in the blood. This suggests that different quantities of testosterone have distinct effects on different activities in your body; some functions can be stabilized with a modest dosage, whereas others require greater doses to observe a difference. This study emphasizes how crucial it is to use the appropriate dosage of testosterone based on the particular bodily systems you want to affect or the health objectives you hope to achieve. 
Psychosexual Side Effects
Men were given varying doses of testosterone cypionate, ranging from 100 mg to 500 mg monthly, in Yates and colleagues' study. The results showed that most men's moods and behaviors were not significantly affected by testosterone, even at high concentrations. However, at 500 mg per week, a small proportion of men began to have substantial psychological side effects, such as feeling excessively agitated and irritated, which is akin to a restless kind of mania. This implies that while many men may take large doses of testosterone without experiencing any problems, there is a threshold—in this case, around 500 mg per week—beyond which there is an increased risk of these negative
psychological effects. 
Weighing Pros and Cons through Informed Caution
These studies all demonstrate that, despite the particular advantages of testosterone therapy, the adverse effects of high doses need to be carefully evaluated. It is crucial to weigh the benefits and drawbacks of TRT, and you should always make this choice while consulting a physician and taking the most recent studies into consideration.
REGENX Health's specialists can help you learn more about safe testosterone treatment. Schedule a consultation now for individualized hormone health solutions.