boosting testosterone and sperm quality
GLP-1 obesity medications may improve sperm quality and increase testosterone levels in men with obesity, according to a systematic review presented at the Endocrine Society’s annual meeting in Chicago, Illinois. While evidence remains preliminary, data suggests these drugs could offer fertility benefits by raising testosterone and improving sperm morphology.
Pratibha Natesh, an endocrinologist at Warwick Medical School in Coventry, UK, co-authored the review. Natesh and her colleagues analyzed randomized controlled trials to determine how GLP-1 drugs—which bind to receptors for the hormone glucagon-like peptide 1 to create a feeling of fullness—impact male fertility.
How do GLP-1 drugs affect testosterone and sperm quality?
The systematic review identified five studies regarding GLP-1 drugs and testosterone. In one trial involving 30 men with obesity and hypogonadism, testosterone levels rose after 16 weeks for those receiving either a GLP-1 drug or testosterone replacement therapy (TRT).
A second study of 25 men with type 2 diabetes and hypogonadism found that GLP-1 drugs improved sperm quality over 24 weeks. Specifically, the percentage of morphologically typical sperm—those with the correct size and shape—increased from 2% to 4%.
Separate research presented at the American Urological Association annual meeting in Washington DC supports these findings. Andrés Guillén-Lozoya, a physician at Mayo Clinic in Rochester, Minnesota, analyzed electronic health records for more than 1,600 men.
Guillén-Lozoya found that testosterone levels increased by approximately 30% after treatment with a GLP-1 drug or a medication mimicking both GLP-1 and glucose-dependent insulinotropic polypeptide.
What is the difference between GLP-1 drugs and TRT for fertility?
The review highlighted a contrast between GLP-1 medications and testosterone replacement therapy (TRT). While both can raise testosterone levels, their effects on sperm differ.
In the study of 25 men with type 2 diabetes, the TRT group saw a greater increase in testosterone than the GLP-1 group. However, sperm count and quality declined in the TRT group, a result the researchers noted is expected during that type of therapy.
The review also noted that GLP-1 medications had no effect on testosterone levels in three studies involving healthy men receiving the drugs for short periods.
What happens next for obesity medication research?
Because the current evidence is preliminary, Natesh states that more robust trials are needed to confirm the association between GLP-1 drugs and improved fertility.
Future research may focus on the long-term sustainability of these testosterone increases. Researchers could also investigate if the fertility benefits are a direct result of the medication or a secondary effect of weight loss.
Frequently Asked Questions
Do GLP-1 drugs increase testosterone in healthy men?
Three studies included in the systematic review involving healthy men receiving the medications for short periods showed no effect on testosterone levels.
How much did testosterone increase in the Mayo Clinic analysis?
According to physician Andrés Guillén-Lozoya, testosterone levels increased by around 30% in a group of over 1,600 men treated with GLP-1 or dual-hormone mimicking drugs.
How does TRT impact sperm compared to GLP-1 drugs?
While TRT can increase testosterone levels more than GLP-1 drugs, it is associated with a decline in sperm count and quality, whereas GLP-1 drugs were linked to improved sperm morphology in one study.
Do you think these findings will change how obesity is treated in men who are also seeking fertility options?