News | GLP-1 drugs may improve testosterone levels and sperm quality in obese men
Beyond weight loss and diabetes treatment, GLP-1 drugs may also be associated with improvements in male reproductive health. Recently, a study to be presented at the American Endocrine Society's annual meeting, ENDO 2026, showed that long-term use of GLP-1 drugs showed no signs of impairing male hormone levels or fertility. On the contrary, in men with obesity-related low testosterone, these drugs may help improve testosterone levels and sperm quality, while addressing the underlying issues of obesity and metabolic abnormalities.
The study was conducted by scientists from University Hospitals Coventry and Warwickshire and Warwick Medical School in the UK. The research team searched medical databases to screen published randomized controlled clinical trials, focusing on the effects of GLP-1 drugs compared to other treatments or placebos on reproductive and metabolic indicators in men aged 18 to 65.
Researchers primarily assessed testosterone levels and changes in other hormones regulating testicular function, while also incorporating indicators such as sperm quality, body weight, blood sugar, cholesterol, and overall metabolic health. To reduce bias, two independent reviewers audited the relevant studies, and ultimately five clinical trials met the inclusion criteria.
Analysis results showed that existing clinical trials did not find negative effects of GLP-1 drugs on male hormone levels, sexual function, or sperm quality. Among them, a 24-week study on semaglutide showed improvements in participants' sperm morphology and cholesterol levels, while testosterone and related hormone levels remained stable. Another 16-week study on liraglutide showed that in men with low testosterone due to overweight or obesity, testosterone and related hormone levels increased after treatment.
The study also suggested that intervening in obesity and metabolic abnormalities may lead to better overall health outcomes compared to testosterone replacement therapy alone. The research team believes this finding has significant clinical implications because obesity itself can affect male reproductive health through various mechanisms, including lowering testosterone levels, affecting sperm production, exacerbating inflammatory states, and disrupting metabolic balance. If the underlying cause can be addressed at the level of weight and metabolic health, male hormone levels and fertility-related indicators may subsequently improve.
Pratibha Natesh, an endocrinology expert at Warwick Medical School and head of the research team, stated that this study supports shifting clinical thinking from "directly prescribing testosterone replacement therapy for obese men with low testosterone" to "prioritizing the treatment of the root cause of overweight and poor metabolic health." She pointed out that improving obesity and metabolic status may allow the body to naturally restore hormone levels while helping to preserve fertility.
This view also addresses an important issue in the treatment of male low testosterone. While testosterone replacement therapy can increase testosterone levels in the blood, it is not always an ideal choice for men with fertility needs, as exogenous testosterone may suppress the hormonal axis that regulates sperm production in the body, thereby affecting sperm generation. In contrast, GLP-1 drugs primarily work by improving body weight, blood sugar, insulin resistance, and metabolic status, theoretically being closer to addressing the cause behind obesity-related low testosterone.
However, researchers emphasize that the current evidence is still in its early stages. Although the results of existing clinical trials are generally positive, the number of included studies is small, and results vary between different studies. Therefore, larger, more rigorously designed, and longer follow-up studies are still needed to fully assess the long-term effects of GLP-1 drugs on male fertility.
The research team also specifically cautioned that most of the observed reproductive benefits are likely indirect effects, i.e., improvements in hormones and sperm indicators brought about by weight loss and improved metabolic health, rather than GLP-1 drugs directly acting as treatments for male infertility or hypogonadism. In other words, GLP-1 drugs have not yet been evaluated as a specific treatment regimen for male infertility or low testosterone.
As GLP-1 drugs such as semaglutide and liraglutide are widely used in the management of obesity and type 2 diabetes, public interest in their long-term safety and potential additional benefits continues to heat up. For men of reproductive age, whether the drugs affect sperm quality, hormone levels, and future fertility plans is a question of practical significance. This study provides a clearer direction of evidence for this issue: at least from existing randomized controlled trials, GLP-1 drugs have not shown signals of reproductive harm and may bring some improvement in men with obesity-related low testosterone.
Natesh stated that the positive impact of improving metabolic health may extend far beyond weight itself. The research team hopes that this evidence-based information can help patients and clinicians view GLP-1 weight loss and diabetes drugs more rationally, considering weight, metabolism, hormones, and fertility needs when making treatment choices.
Overall, this study provides new insights for the management of reproductive health in obese men. In the future, if more research confirms that GLP-1 drugs can safely improve testosterone levels and sperm quality, the management of male low testosterone and fertility may place greater emphasis on treating metabolic causes rather than relying solely on hormone replacement.
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Published 2026-06-21
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News | GLP-1 drugs may improve testosterone levels and sperm quality in obese men
News | GLP-1 drugs may improve testosterone levels and sperm quality in obese men
Beyond weight loss and diabetes treatment, GLP-1 drugs may also be associated with improvements in male reproductive health. Recently, a study to be presented at the American Endocrine Society's annual meeting, ENDO 2026, showed that long-term use of GLP-1 drugs showed no signs of impairing male hormone levels or fertility. On the contrary, in men with obesity-related low testosterone, these drugs may help improve testosterone levels and sperm quality, while addressing the underlying issues of obesity and metabolic abnormalities.
The study was conducted by scientists from University Hospitals Coventry and Warwickshire and Warwick Medical School in the UK. The research team searched medical databases to screen published randomized controlled clinical trials, focusing on the effects of GLP-1 drugs compared to other treatments or placebos on reproductive and metabolic indicators in men aged 18 to 65.
Researchers primarily assessed testosterone levels and changes in other hormones regulating testicular function, while also incorporating indicators such as sperm quality, body weight, blood sugar, cholesterol, and overall metabolic health. To reduce bias, two independent reviewers audited the relevant studies, and ultimately five clinical trials met the inclusion criteria.
Analysis results showed that existing clinical trials did not find negative effects of GLP-1 drugs on male hormone levels, sexual function, or sperm quality. Among them, a 24-week study on semaglutide showed improvements in participants' sperm morphology and cholesterol levels, while testosterone and related hormone levels remained stable. Another 16-week study on liraglutide showed that in men with low testosterone due to overweight or obesity, testosterone and related hormone levels increased after treatment.
The study also suggested that intervening in obesity and metabolic abnormalities may lead to better overall health outcomes compared to testosterone replacement therapy alone. The research team believes this finding has significant clinical implications because obesity itself can affect male reproductive health through various mechanisms, including lowering testosterone levels, affecting sperm production, exacerbating inflammatory states, and disrupting metabolic balance. If the underlying cause can be addressed at the level of weight and metabolic health, male hormone levels and fertility-related indicators may subsequently improve.
Pratibha Natesh, an endocrinology expert at Warwick Medical School and head of the research team, stated that this study supports shifting clinical thinking from "directly prescribing testosterone replacement therapy for obese men with low testosterone" to "prioritizing the treatment of the root cause of overweight and poor metabolic health." She pointed out that improving obesity and metabolic status may allow the body to naturally restore hormone levels while helping to preserve fertility.
This view also addresses an important issue in the treatment of male low testosterone. While testosterone replacement therapy can increase testosterone levels in the blood, it is not always an ideal choice for men with fertility needs, as exogenous testosterone may suppress the hormonal axis that regulates sperm production in the body, thereby affecting sperm generation. In contrast, GLP-1 drugs primarily work by improving body weight, blood sugar, insulin resistance, and metabolic status, theoretically being closer to addressing the cause behind obesity-related low testosterone.
However, researchers emphasize that the current evidence is still in its early stages. Although the results of existing clinical trials are generally positive, the number of included studies is small, and results vary between different studies. Therefore, larger, more rigorously designed, and longer follow-up studies are still needed to fully assess the long-term effects of GLP-1 drugs on male fertility.
The research team also specifically cautioned that most of the observed reproductive benefits are likely indirect effects, i.e., improvements in hormones and sperm indicators brought about by weight loss and improved metabolic health, rather than GLP-1 drugs directly acting as treatments for male infertility or hypogonadism. In other words, GLP-1 drugs have not yet been evaluated as a specific treatment regimen for male infertility or low testosterone.
As GLP-1 drugs such as semaglutide and liraglutide are widely used in the management of obesity and type 2 diabetes, public interest in their long-term safety and potential additional benefits continues to heat up. For men of reproductive age, whether the drugs affect sperm quality, hormone levels, and future fertility plans is a question of practical significance. This study provides a clearer direction of evidence for this issue: at least from existing randomized controlled trials, GLP-1 drugs have not shown signals of reproductive harm and may bring some improvement in men with obesity-related low testosterone.
Natesh stated that the positive impact of improving metabolic health may extend far beyond weight itself. The research team hopes that this evidence-based information can help patients and clinicians view GLP-1 weight loss and diabetes drugs more rationally, considering weight, metabolism, hormones, and fertility needs when making treatment choices.
Overall, this study provides new insights for the management of reproductive health in obese men. In the future, if more research confirms that GLP-1 drugs can safely improve testosterone levels and sperm quality, the management of male low testosterone and fertility may place greater emphasis on treating metabolic causes rather than relying solely on hormone replacement.
Story source:
Online collection