Testosterone Nasal Gel Potentially Safe, Effective in Hypogonadism

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Three doses of testosterone nasal gel may help normalize testosterone levels in men with hypogonadism.

SAN DIEGO — A new testosterone nasal gel may help raise low testosterone levels to normal with few side effects in men with hypogonadism, according to the results of a phase 3 clinical trial presented ENDO 2015. 

Researchers conducted a 90-day, randomized, open-label, dose-ranging study and found that testosterone nasal gel is an effective and practical alternative to other available testosterone replacement therapy products.

In May 2014, the U.S. Food and Drug Administration (FDA) approved the first testosterone nasal gel, which is sold as Natesto (Trimel Pharmaceuticals). 

“The unique delivery system makes this a convenient and easy-to-use, self-administered form of testosterone to treat adult males with hypogonadism,” said the study’s lead investigator Alan Rogol, MD, PhD, who is professor emeritus at the University of Virginia in Charlottesville. “Also important is that intranasal testosterone minimizes the risk of unwanted secondary exposure of testosterone to women or children.”

Dr. Rogol, who is a consultant to Trimel, said the new formulation sends testosterone directly into the nostril. The product comes in a multiple-dose pump dispenser that administers a specified amount of testosterone gel (5.5 mg) inside each nostril.

For this study, he and his colleagues conducted a phase 3 clinical trial evaluating the effectiveness and safety of this new product in 306 men with low testosterone. The trial was conducted at 39 outpatient centers in the U.S. To qualify for participation, all the men were required to have at least two fasting morning total serum testosterone levels <300 ng/dL.  

The men used the treatment for 90 days in both nostrils either twice a day (n=228) or three times a day (n=78) as randomly assigned. This was done to examine the most effective dose. 

The men stayed on the drug for another 90 or 180 days to evaluate tolerance to the medication and effects of treatment.

After 90 days of treatment, the average testosterone concentration in the blood was in the normal range for 90% of men who used the nasal gel three times daily, compared with 71% of men using it twice a day. Currently, the manufacturer’s recommended dosing is three times a day in each nostril, for a total daily dose of 33 mg.

Dr. Rogol said in this study, the treatment strongly improved men’s erectile function and mood. No serious medical problems related to the medication occurred in either dosing group.

In addition, Dr. Rogol noted that rates of problems with tolerating the nasal gel were low, with 3.7% of men in the group receiving three daily doses discontinuing use of the medication because of side effects. 

Among 99 men in the trial who completed a survey on their experience with the drug, 84% felt confident they were correctly using the pump applicator within 2 days of beginning treatment.

Dr. Rogol said this trial was conducted because an easy but safe delivery system for testosterone was not available before now. 

“Nasal testosterone, as formulated as Natesto, is an FDA-approved formulation of testosterone for the treatment of men with hypogonadism, whether primary or secondary. This is the first study to show that this particular dosing form is safe and efficacious. The drug itself is not new. What is new is the gel formulation and the self-administration device,” Dr. Rogol told Endocrinology Advisor.


  1. Rogol A et al. Abstract SAT-122. Presented at: The Endocrine Society’s 97th Annual Meeting & Expo (ENDO 2015); March 5-8, 2015; San Diego.