Large Study of 9,500 Men Shows Testosterone Therapy Delivers Real-Life Benefits—With a Good Safety Record

A comprehensive study of 9,537 men has found that testosterone therapy delivered meaningful improvements in sexual function, energy levels, and overall quality of life—while maintaining a reassuring safety profile. The research, which tracked participants for an average of 8.47 months, represents one of the largest real-world analyses of testosterone treatment outcomes to date.

What Did This Large-Scale Study Actually Find?

Unlike controlled clinical trials that often use limited treatment approaches, this study examined how testosterone therapy works in actual clinical practice, where doctors commonly combine multiple treatments. The results showed significant improvements across all eight quality of life areas measured, with libido scores increasing by an average of 1.26 points on a 5-point scale.

The study's scope was impressive—researchers analyzed data from men treated by Menwell Ltd, a UK-based men's health provider, between 2019 and 2024. The median age was 42 years, and participants received various combinations of treatments that reflect real-world medical practice.

How Were the Men Actually Treated?

The treatment approaches varied significantly, mirroring what happens in actual medical practice rather than the narrow protocols typically used in research studies. The most common treatments included:

• Subcutaneous testosterone injections: Used by 8,517 men (89.20% of participants), representing the most popular delivery method
• Human chorionic gonadotropin (hCG): Prescribed to 7,079 men (75.23%), often used to maintain natural testosterone production
• Tadalafil: Given to 1,308 men (13.72%), commonly used to address erectile dysfunction alongside testosterone issues
• Clomiphene citrate: Prescribed to 675 men (7.08%), used to stimulate the body's own testosterone production
• Transdermal testosterone: Used by 366 men (3.84%), applied as gels or patches

Many men received multiple treatments simultaneously, which is common in clinical practice but rarely studied in formal research trials.

Was the Treatment Safe for Long-Term Use?

Safety concerns often dominate discussions about testosterone therapy, but this study found reassuring results. The average increase in hematocrit—a blood measurement that can indicate thickening of the blood—was minimal at just 0.03 L/L by month 12. Importantly, there was no significant difference in the rate of hematocrit levels exceeding the concerning threshold of 0.54 between different treatment groups.

The researchers noted that recent landmark trials have shown testosterone therapy is not associated with increased risks of cardiovascular disease or prostate cancer, adding context to the safety profile observed in their study.

The study's findings suggest that testosterone therapy, when properly monitored in real-world clinical settings, can provide substantial quality of life improvements while maintaining an acceptable safety profile. The research team emphasized that future studies should focus on developing more nuanced treatment algorithms that consider individual factors like age, symptom severity, and baseline testosterone levels to identify men most likely to benefit from therapy.