As males age, their testosterone levels may decline by up to 2% annually after age 30 years. Some research also suggests that high levels of prenatal testosterone levels may be linked to autism in children. However, there’s no official consensus on healthy testosterone levels. Research on testosterone therapies is still developing, in particular around the potential risks of increasing its levels in a person. According to a 2017 article, if a person has hypogonadism, the best course of action is to begin testosterone therapy once they know the risks. A person may have a condition that causes low testosterone levels — most commonly hypogonadism. Overdoing intensity techniques like drop set training to failure can lead to overtraining and psychological burnout as well as lower levels of anabolic hormones like IGF-1 and testosterone.13
The Panel recommends that clinicians use the same laboratory with the same method/instrumentation for serial total testosterone measurement. As an example, a total testosterone value of 250 ng/dL may be considered low based on the current guideline but be marked within the normal range by the laboratory. Well-established reference ranges constitute the essential basis for identifying whether the circulating levels of a particular analyte, testosterone in this case, are normal or low. Other population-based studies have attempted to measure prevalence, but have not used standard methodology, which makes arriving at a definitive number of testosterone deficiency difficult.
In the final and rate limiting step, the C17 keto group androstenedione is reduced by 17β-hydroxysteroid dehydrogenase to yield testosterone. Like other steroid hormones, testosterone is derived from cholesterol (Figure 1). In contrast to testosterone, DHEA and DHEA sulfate have been found to act as high-affinity agonists of these receptors. The bones and the brain are two important tissues in humans where the primary effect of testosterone is by way of aromatization to estradiol. Greatly differing amounts of testosterone prenatally, at puberty, and throughout life account for a share of biological differences between males and females. The areas of binding are called hormone response elements (HREs), and influence transcriptional activity of certain genes, producing the androgen effects.
For men with on-treatment testosterone levels that fall below the suggested target range but who experience complete resolution of symptoms, there is no need to titrate dosing. For men with on-treatment testosterone levels that fall below the suggested target range but who have on-treatment amelioration of symptoms, up-titration may be considered in an effort to achieve symptom abolition. While this period of waiting might preclude the need for testosterone therapy by allowing testosterone to return to normal levels organically, it is possible that men who underwent long courses of ADT may not regain physiological testosterone levels even one year after cessation of ADT.349, 350 It is the opinion of this Panel that until there is definitive evidence demonstrating that testosterone therapy is not safe for use in prostate cancer patients, the decision to commence testosterone therapy in men with a history of prostate cancer is a negotiated decision based on the perceived potential benefit of treatment. Included studies had significant heterogeneity with the populations themselves, methods of assessment, study durations, baseline population characteristics, and number of participants, leading the Panel to conclude that there is currently insufficient evidence to determine if testosterone therapy impacts QoL in a meaningful way. Despite the absence of definitive evidence, the Panel recommends that patients with these symptoms be counseled regarding the possibility of improvement on testosterone therapy. In men with testosterone deficiency, testosterone therapy results in increased lean muscle mass and reduced fat mass, but no overall changes in BMI.
Men who seek medical care for possible testosterone therapy often present with non-specific symptoms, such as low energy and fatigue, which can be manifestations of other conditions, such as chronic stress, chronic fatigue, and depression. As with other symptoms, the duration of testosterone therapy likely has a significant impact on overall bone density benefits. At the present time, there are insufficient data available to predict which men with ED are most likely to respond to testosterone therapy. While the Panel is unable to quantify what percentage of men with ED and testosterone deficiency experience clinically meaningful improvements in erectile function (in contrast to statistically significant improvements) or the ability to achieve a functional erection, it is clear that some men will have improvement in erectile function with testosterone therapy. In 2013, the AUA published the Early Detection of Prostate Cancer Guideline,222 which makes no specific statements about PSA screening in men with testosterone deficiency or in men on testosterone therapy. Clinicians should be aware that symptomatic gynecomastia or other breast symptoms are an uncommon side effect in men on testosterone therapy.
Most clinics start with a conservative weekly total and then titrate to symptoms and labs. TRT is a doctor-prescribed treatment for confirmed low testosterone (hypogonadism). This guide uses a clear, practical testosterone injection dosage chart and plain-language explanations to help you understand what clinicians consider when adjusting therapy. Your ideal plan depends on diagnosis, symptoms, blood test results, and how you metabolize medication over time. We also cover women’s considerations, safety checkpoints, and a simple way to split doses for steadier day-to-day levels. If you experience any adverse effects, it’s always best to seek advice from your doctor.
To merely refer to injectable or gel testosterone formulations without differentiation does not impart complete and accurate information to the reader. For example, there are several testosterone gels available in 1%, 1.62%, and 2% formulations, each marketed under a different brand or generic name. While all products contain the same medication (testosterone), each product and modality has distinct pharmacokinetic and application attributes based on the excipient agents and the permeator components. The testosterone therapeutic space is relatively unique. Expert Opinion refers to a statement, achieved by consensus of the Panel, that is based on members' clinical training, experience, knowledge, and judgment for which there is no evidence.
In addition, a continuous increase in vaginal sexual arousal may result in higher genital sensations and sexual appetitive behaviors. Men who watch sexually explicit films also report increased motivation and competitiveness, and decreased exhaustion. In non-human primates, it may be that testosterone in puberty stimulates sexual arousal, which allows the primate to increasingly seek out sexual experiences with females and thus creates a sexual preference for females. Therefore, these mammals may provide a model for studying clinical populations among humans with sexual arousal deficits such as hypoactive sexual desire disorder. Studies conducted in rats have indicated that their degree of sexual arousal is sensitive to reductions in testosterone. Testosterone treatment for reasons other than possible improvement of sexual dysfunction may not be recommended.