Predefined subgroups were established to explore explanations for inconsistency between studies. Whenever appropriate (more than 10–20 studies and low between-study heterogeneity), we assessed publication bias using the Egger regression asymmetry test and visual inspection of funnel plots (26, 27). A panel of experts from The Endocrine Society provided the content expertise and developed a priori protocol for this systematic review and meta-analysis. T plays an important role in female sexual function, is considered a major driver for sexual desire, and modulates the response to sexual stimuli (3). Long-term safety data were sparse, and the quality of such evidence was low. We conducted study selection, data extraction, and appraisal in duplicate. The use of T has been suggested to improve women's health during the postmenopausal period. We conducted a systematic review with meta-analysis of individual participant data according to current methodological standards. We also assessed the clinical and cost-effectiveness of testosterone replacement therapy for men with male hypogonadism, and the existing qualitative evidence on men's experience and acceptability of testosterone replacement therapy. Due to the above-mentioned advantages, TTh has clearly gained popularity among hypogonadal males as a safe and beneficial treatment, with increasing evidence of favourable effects on multiple organ systems. A plethora studies have not demonstrated testosterone concentrations to be higher in men with prostate cancer compared to those without cancer. PSA is often used as a marker of prostate health, and several studies have investigated this association and at how TRT affects PSA. For a long time, it was believed that higher testosterone concentrations increased the risk of prostate cancer or caused rapid cancer growth, while low testosterone concentrations would have a protective outcome. Animal studies, case reports and studies not written in English were excluded. The aim of the present review was to consolidate the recent data on the four main innovations in TTh. The first-generation oral testosterone undecanoate (TU) product then to scrotal and non-scrotal testosterone patches and then to topical testosterone gels . Different therapeutic options have been reported from implanted testosterone pellets to injectable testosterone esters, short and long acting and then to oral methyltestosterone. Each approach has advantages and disadvantages, and the choice of the method of TRT will often be determined by patient preference or co-medication (no intramuscular injections in patients under coumarin or similar anticoagulants). Numerous studies have demonstrated the benefits of TTh in overtly hypogonadal men. The quality of evidence is low, due to increased risk of bias and imprecision. The quality of evidence for these outcomes ranged from low to moderate, due to high heterogeneity and low-to-moderate risk of bias. Randomization method was adequate in 35%, with adequate allocation concealment reported in 75% of all; more than 90% masked patients and study investigators. A decision-analytic Markov model was developed to evaluate the cost per quality-adjusted life-years of the use of testosterone replacement therapy in cohorts of patients of different starting ages. We performed one-stage meta-analyses using the acquired individual participant data and two-stage meta-analyses to integrate the individual participant data with data extracted from eligible studies that did not provide individual participant data. Evidence was considered from placebo-controlled randomised controlled trials assessing the effects of any formulation of testosterone replacement therapy in men with male hypogonadism. Furthermore, published studies have not specifically evaluated whether TTh resulted in normalization of T levels. To investigate the long-term effects of TTh, real-world evidence (RWE) is required. Recognition of the value of TTh in diabetes is evolving—one major professional society recommends its use when TD is present, whereas a second advocates testing for testosterone in men with symptoms of TD but does not yet recommend treatment.29,30 Clearly, therefore, testosterone should be measured in all type 2 diabetes and obese patients. Among the early T2DM patients, there was a reversal of diabetes in 45.2% in the testosterone arm and only 32.1% in the control arm. It has also been demonstrated that T2DM patients with HH have increased insulin resistance when compared with those without.28 TTh restores insulin sensitivity and enhances genes in the insulin signaling pathway, whereas simultaneously reducing adiposity and increasing muscle mass.15 Consistent with these observations, TTh has been shown to prevent the development of T2DM. After bariatric surgery, testosterone levels normalized in the majority after 2 years and were maintained in those who maintained their weight loss but diminished again if they regained weight.27 Thus, body weight is a major determinant of plasma testosterone concentrations. The authors suggest that TRT does not increase the risk of prostate cancer. Moreover, reports have shown that hypogonadal men with normal PSA levels do not have lower cancer rates than the general healthy population . PSA is not the perfect marker for prostate cancer; so, several studies have tried to clarify if TRT increases the occurrence of prostate cancer. Our systematic review reflects the current state of the best available evidence through updating previous reviews. Lack of data on T dose and T level achieved add another layer of uncertainty to the clinical implications of our findings. Communication of these results to patients requires knowledge of the minimally important difference of each scale (recognized by patients) and the use of shared decision-making tools. Daily insulin dose in patients receiving insulin at baseline was reduced from 38.0 to 4.1 U/d. There were 190 men in the TTh group and 180 men in the control group, all of whom received standard diabetes treatment, including lifestyle modification courses at the local diabetes center. An ongoing prospective observational study in a urological office in Germany was initiated in 2004. Tempering these results was an observation of increased hematocrit in ∼25% of men receiving TTh, although only 6% had two such readings, justifying study withdrawal. In a randomized placebo-controlled trial, obese men with impaired glucose tolerance or early diabetes, and with testosterone concentrations 16 There was a 41% reduction in incidence of T2DM in the testosterone arm. A study in severely obese young males between 14 and 20 years of age revealed HH in 75% of them. Pastuszak et al published a series of 103 hypogonadal men receiving TTh, of which 26 men were considered high risk.19 High risk was defined as having positive surgical margins, positive lymph nodes, or positive surgical margins.