CHICAGO — A troubling trend in modern medicine has been brought to the forefront by new research presented at ENDO 2026, the annual meeting of the Endocrine Society. A retrospective study conducted by clinicians at the University of Michigan (UMich) has revealed that a significant portion of testosterone therapy (T-therapy) prescriptions in the United States lack the necessary diagnostic rigor required by clinical standards. The findings suggest that the widespread, often casual use of testosterone supplements is frequently occurring in the absence of verified androgen deficiency, and in some cases, despite the presence of dangerous medical contraindications.
The State of the Science: Main Facts and Findings
The investigation, which analyzed a random sample of 200 male patients at a single major academic institution, found that a staggering 88% of patients receiving testosterone prescriptions had not undergone testing that aligned with the Endocrine Society’s clinical practice guidelines.
According to established medical standards, a diagnosis of hypogonadism—the clinical condition for which testosterone therapy is indicated—requires a specific, multi-step diagnostic process. This includes two separate, low morning testosterone level measurements (taken between 5 a.m. and 10 a.m.), followed by an evaluation of luteinizing hormone (LH) and/or follicle-stimulating hormone (FSH) to determine the cause of the deficiency. Furthermore, the guidelines mandate a thorough screening for contraindications, such as untreated sleep apnea, elevated prostate-specific antigen (PSA) levels, or a history of hormone-sensitive cancers.
The UMich study found that only 12% of the sampled patients met this high threshold of guideline-concordant care. Perhaps more alarmingly, nearly 40% of the patients who received the hormone had undergone the basic laboratory checks but were prescribed the medication despite having documented medical conditions that specifically advise against the use of testosterone.
Chronology of the Testosterone Boom
To understand the gravity of these findings, one must look at the historical context of testosterone prescribing in the U.S. Over the last three decades, prescriptions for testosterone have quadrupled. This explosion in usage has occurred even as the actual prevalence of male hypogonadism in the general population has remained relatively stable.
The Last 30 Years of Growth
In the 1990s and early 2000s, testosterone was primarily reserved for men with clear, pathological conditions such as Klinefelter syndrome or pituitary tumors. However, the mid-2000s saw a shift in marketing and patient awareness, with "Low T" becoming a household term. By the 2010s, direct-to-consumer advertising and the rise of "men’s health clinics" fueled a surge in prescriptions for symptoms that are often non-specific, such as fatigue and decreased libido.
Recent Trends (2018–2022)
A recent cross-sectional study published in PLOS ONE highlights that this growth is not slowing down; rather, it is permeating younger demographics. Between 2018 and 2022, testosterone use increased significantly across every age group:
- Ages 24 and under: 120% increase
- Ages 25–34: 86% increase
- Ages 35–44: 45% increase
- Ages 45–54: 35% increase
- Ages 55–64: 17% increase
- Ages 65 and older: 12% increase
The data indicates that the most rapid growth is occurring among younger men, many of whom may be seeking performance enhancement or "lifestyle" benefits rather than treatment for a genuine endocrine disorder.
Supporting Data: Why Are Men Seeking Testosterone?
The UMich retrospective review provided a granular look at why men are presenting for treatment and the physical state of the patients involved. The median patient in the study was 56 years old, with a median BMI of 32, placing the average patient firmly in the "obese" category.
Triggering Symptoms
When researchers analyzed the medical records to see why these patients were initially evaluated for hypogonadism, the motivations were consistent with broader societal trends:
- Fatigue: 63%
- Erectile Dysfunction: 62%
- Decreased Libido: 54%
- Patient Request: 25%
While these symptoms are common in hypogonadism, they are also classic indicators of obesity, sleep apnea, metabolic syndrome, and depression—conditions that do not necessarily respond to testosterone and may actually be exacerbated by it.
The Burden of Contraindications
The study identified a high prevalence of comorbidities that make testosterone therapy risky. Over half (55%) of the patients had documented Obstructive Sleep Apnea (OSA), a condition that can be worsened by the physiological effects of testosterone. Additionally, 4% of the cohort had a history of prostate cancer, and 1.5% had a PSA greater than 4 ng/mL, both of which are significant red flags for testosterone supplementation, as testosterone can potentially stimulate the growth of existing prostate cancer cells.
Furthermore, the data showed that patients with two or more comorbidities (such as hypertension, diabetes, and obesity) were significantly less likely to receive an appropriate, guideline-concordant work-up compared to healthier patients (OR 0.25). This suggests that in the most medically complex patients—those who arguably need the most careful management—the clinical rigor was actually lower.
Official Responses and Perspectives
Sophia Sinha, MD, of the University of Michigan, who presented the findings at ENDO 2026, expressed concern over the "discrepancy in testosterone prescribing practice." She emphasized that the primary motivation for the study was to quantify the risks being taken by clinicians, noting that testosterone therapy carries well-documented hazards including hypertension, erythrocytosis (the thickening of blood), infertility, and the potential for psychological dependence or abuse.
Maria Papaleontiou, MD, also of UMich, emphasized that the data should be viewed as a call to action. "These findings highlight opportunities to improve patient care and reduce inappropriate testosterone prescribing," Dr. Papaleontiou stated. "Long-term, these findings can lead to quality-improvement efforts and clinical decision support tools that promote consistent, guideline-concordant testosterone prescribing."
The Specialty Gap
The study also revealed a clear divide between medical specialties regarding diagnostic adherence. When patients received their prescriptions through endocrinologists (OR 12.05) or urologists (OR 5.62), they were significantly more likely to have undergone appropriate diagnostic evaluations compared to those whose testosterone was prescribed by primary care physicians (who accounted for 45% of all prescriptions). This suggests that specialized training in hormonal regulation plays a critical role in ensuring that patients are screened correctly before initiating lifelong hormone therapy.
Implications for Future Medical Practice
The implications of this study are far-reaching. As the use of testosterone continues to climb, the medical community faces a potential public health issue involving thousands of men being exposed to unnecessary medication that carries legitimate cardiovascular and oncological risks.
The Need for Clinical Decision Support
Dr. Sinha suggests that the way forward involves integrating technology into the electronic health record (EHR). Clinical decision support tools could automatically flag when a patient does not meet the necessary criteria for a prescription—such as lacking the required lab results or having a documented history of prostate cancer. By creating "hard stops" in the prescribing software, health systems could force adherence to established safety protocols.
Addressing the "Lifestyle" Narrative
There is also a broader need for education—both for clinicians and patients. Many patients are under the impression that testosterone is a "fountain of youth" for aging men, ignoring the reality that symptoms like fatigue are often better addressed through weight loss, exercise, and the treatment of underlying metabolic conditions. If 63% of the cohort was obese, addressing weight and sleep apnea would likely resolve many of the symptoms that led them to seek testosterone in the first place, without the need for exogenous hormone supplementation.
Future Research Directions
The research team at UMich advocates for further studies that focus on intervention. It is no longer enough to document that the problem exists; future research must evaluate whether mandatory educational modules for primary care providers or standardized diagnostic pathways can effectively lower the rate of inappropriate prescribing.
As the medical field grapples with the fallout of the "Low T" marketing wave, the UMich study serves as a stark reminder that even widely prescribed medications must be treated with caution. The transition from a "symptom-first" approach to a "testing-first" approach is essential to ensuring that testosterone therapy remains a tool for treating genuine disease, rather than a misapplied solution for the systemic health challenges of an aging population.
