By Dr. John A. Robinson, NMD & Dr. Cristina Romero-Bosch, NMD
The Hormone Zone
GLP-1 medications have transformed the conversation around weight loss, but their effects go far beyond the scale. Semaglutide and tirzepatide influence insulin sensitivity, inflammation, appetite, cardiovascular risk, reward signaling—and increasingly, we are learning, sexual and reproductive health.
Three recent papers in the sexual-medicine literature caught our attention because they tell a fascinating story. GLP-1 medications may improve testosterone, erectile function and reproductive parameters in some patients while potentially reducing sexual arousal or reward signaling in others.
That may sound contradictory, but it really is not.
At The Hormone Zone, we have always emphasized that sexual health, metabolic health and hormonal health are deeply interconnected, but they are not interchangeable. Treating one does not automatically treat the others.
GLP-1s May Improve Testosterone and Male Reproductive Health
A 2026 systematic review in The Journal of Sexual Medicine examined 10 studies involving 639 men treated with GLP-1 receptor agonists. Total testosterone generally increased, particularly among men with obesity, type 2 diabetes or functional hypogonadism. LH and FSH were maintained or sometimes increased, and several studies also reported improvements in sperm concentration, motility and morphology.
This makes physiological sense.
Obesity and insulin resistance can suppress normal male reproductive function through inflammation, increased aromatization, metabolic dysfunction and disruption of the hypothalamic-pituitary-gonadal axis. Improve that metabolic environment and the reproductive system may begin functioning better.
This is different from simply giving a man testosterone. Exogenous testosterone can suppress LH, FSH and sperm production. GLP-1 therapy may improve testosterone in metabolically unhealthy men while preserving reproductive signaling.
That could be especially important for younger men with obesity-associated hypogonadism who still desire fertility.
Weight Loss Can Improve Sex—but There Is More Going On
A second 2026 review in Sexual Medicine Reviews examined weight-loss medications and sexual function more broadly.
In men, GLP-1 therapy has been associated with improvements in erectile function, testosterone and sperm parameters. The evidence in women remains much more limited.
Again, the biology makes sense. Erectile function depends heavily on vascular and metabolic health. Improve insulin sensitivity, body composition, inflammation and cardiovascular function, and sexual function may improve with it.
But GLP-1 receptors also exist in brain regions involved in appetite, motivation, attention and reward.
That raises a fascinating question:
Could a medication improve someone’s physical ability to have sex while simultaneously reducing how strongly they want it?
Potentially.
Sexual function requires more than hormones and blood flow. It also requires desire, motivation, anticipation and reward.
The Tirzepatide Case That Raises a New Question
The third paper is particularly interesting.
Researchers reported a 44-year-old woman with lifelong persistent genital arousal disorder/genitopelvic dysesthesia, or PGAD/GPD. This is not simply “high libido.” It involves unwanted genital sensations or arousal that may occur without corresponding sexual desire and can be extremely distressing.
She started tirzepatide for weight loss.
Within two days, she reported approximately a 95% reduction in her symptoms.
That timing is far too fast to explain through meaningful weight loss, improved vascular health or metabolic remodeling. The authors instead proposed that GLP-1/GIP signaling may have altered reward, attention or sensory-processing pathways within the brain.
This is only a case report, and we should not overinterpret it. But it raises an intriguing question about how incretin medications may affect sexual arousal at the neurological level.
This is also where my clinical experience differs from what this case might make people fear.
We have been prescribing GLP-1 medications for more than six years, and we have never seen this kind of dramatic suppression of sexual arousal in my patients.
We suspect one reason is simply how we practice medicine.
At The Hormone Zone, we generally do not treat weight in isolation. Many of our patients have already had their sexual dysfunction addressed before we even get to weight-loss goals. Others are undergoing treatment for sexual function at the same time they are losing weight.
That may include optimizing estrogen, progesterone and testosterone when appropriate. It may include treating erectile dysfunction, vaginal and vulvar tissue health, pelvic floor dysfunction and endothelial function. Depending on the patient, we may also incorporate bremelanotide, oxytocin, PRP procedures such as the O-Shot®, and other individualized sexual-health therapies.
In other words, the patient is not simply receiving a GLP-1 and being told to lose weight.
We are asking: How are your hormones? How is your libido? How is your sexual response? How is your energy? How is your body composition? And how do you actually feel?
The GLP-1 Sexual Paradox
Taken together, these studies suggest what we might call the GLP-1 sexual paradox.
On one side, GLP-1 therapy may improve the biological environment needed for healthy sexual function:
Weight loss → improved insulin sensitivity → better vascular health → improved hormonal signaling → potentially better erections and reproductive function.
On the other side:
GLP-1/GIP signaling → altered reward and attention pathways → potentially less salience or motivation around food, alcohol and perhaps sexual stimuli in susceptible individuals.
Both things may be true at the same time.
A man’s testosterone and erections could improve while his spontaneous desire decreases. Another patient may experience dramatically better sexual function because improved metabolic health, optimized hormones and better body composition outweigh any dampening of reward.
This is why we do not believe weight loss should be practiced as isolated medicine.
Don’t Just Lose Weight. Get Healthier.
The goal of GLP-1 therapy should never simply be to make the number on the scale smaller.
We want to preserve muscle. We want healthy hormones. We want energy, cardiovascular improvement, cognitive health and good sexual function.
If someone loses 40 pounds but loses libido, energy and muscle along the way, we should not automatically call that successful treatment.
Sexual function is one of the best windows we have into the health of the entire person because it depends simultaneously on hormones, blood vessels, nerves, metabolism, neurotransmitters, psychology and relationships.
The emerging research on GLP-1s reinforces the approach we have taken at The Hormone Zone for years: treat the whole person, not simply a hormone level, metabolic marker or number on a scale.
Because ultimately, the goal is not simply weight loss.
It is better health and better living.
Sources
Deameh MG, et al. Effects of glucagon-like peptide-1 receptor agonists on male reproductive hormones, semen parameters, and metabolic outcomes: a systematic review. Journal of Sexual Medicine. 2026.
Fuentes-Mendoza JM, et al. Beyond metabolism: sexual dysfunction and weight-loss drugs. Sexual Medicine Reviews. 2026.
Burr E, et al. The use of tirzepatide to successfully treat persistent genital arousal disorder/genitopelvic dysesthesia: a case report. Sexual Medicine. 2025.
