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Nasal Gel Treats Low Testosterone Without Harming Sperm Production

Currently, for men with low testosterone (low-t) and erectile dysfunction, many of the prescribed testosterone replacement therapies also cause a marked decrease in sperm production. For older men, this may be less of a concern than for younger men who are still planning to have children. Clinical researchers at the University of Miami Miller School of Medicine are conducting a Phase IV clinical trial of the nasal testosterone gel Natesto – and the early results are promising.

Natesto was approved by the FDA in 2014 as a low testosterone therapy. Unlike other testosterone replacements, it does not cause the body to maintain high testosterone levels throughout the day. Because of this, Ranjith Ramasamy, M.D., assistant professor of urology at the Miller School and director of male reproductive medicine and surgery at UHealth – University of Miami Health System, and his team believe that Natesto is a promising low-t treatment option for younger men concerned about maintaining fertility.

Early results show signs that the gel does help restore total serum testosterone to normal levels, and assists men with ED while balancing mood swings. “It is intended as a replacement therapy in adult males for conditions associated with a deficiency or absence of endogenous testosterone,” said Dr. Ramasamy.

There are 5.5 mg of testosterone in 122.5 mg of Natesto gel, administered nasally three times a day. Because it’s short acting, it preserves the production of hormones from the pituitary gland that’s responsible for sperm production. “Our goal is to see if the gel preserves testis size and fertility, which is vital because other testosterone products cause testis atrophy and infertility,” Dr. Ramasamy said. “UM is the only site in the country that is conducting this type of clinical trial.”

Dr. Ramasamy explains that the mucous membrane in the nose is an ideal drug receptor. It quickly absorbs the medication, allowing it to enter into the bloodstream faster, with more effective results. “Patients feel the effects right away, as opposed to some other preparations where they have to wait a few days, sometimes even a few weeks before it begins to work,” he said. “They’re very happy with the results.”

Testosterone: possibly the body’s most essential hormone

Testosterone promotes masculine or male characteristics during puberty and throughout life, increases muscle growth, and increases bone mass. It also helps the body produce red blood cells and sperm, and is essential to overall health. Though testosterone levels are substantially higher in men, women also produce a small amount of the hormone. In addition to enhancing the sex drive in both men and women, testosterone plays a key role in the growth and repair of reproductive tissues. About one in 10 men experience low testosterone levels, especially when aging.

Although opinions differ about what constitutes low testosterone, the diagnosis usually accompanies a blood testosterone level of less than 300 ng/dL in men.

Those aiming to restore optimal testosterone levels should seek to bring the hormone to the range of 425 to 1,000 ng/dL. Women usually have a much lower range, averaging 21 ng/dL.

The end goal of this Phase IV clinical trial is to discover if Natesto, a testosterone replacement medication, can consistently boost testosterone levels without lowering a patient’s sperm count.

For more information about the trial, contact Manuel Leyba Molina at 305-243-4783, ext. 1176, or m.molina.leyba@miami.edu.

Tags: Dr. Ranjith Ramasamy, erectile dysfunction, nasal testosterone gel