By Sandra Rose  | 

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U.S. doctors have started prescribing hormone replacement therapy for men after learning that men are more likely to die from Covid-19 than women.

The coronavirus that causes Covid-19 uses ACE2 (Angiotensin-converting enzyme 2) as a pathway to enter human cells. ACE2 is expressed in the lungs, kidneys, and testicles.

Doctors are hoping estrogen will help protect men from the virus. Estrogen is naturally present in the blood of both sexes, but women have much higher levels of the sex hormone than men for the purpose of reproduction and carrying a baby to term.

According to the NY Times, two clinical trials are currently underway to determine whether dosing men with female sex hormones will protect them from the virus.

Last week, doctors on Long Island started treating male Covid-19 patients with Estradiol to boost their immune systems.

Los Angeles doctors will begin treating Covid-19 patients next week, according to the Times.

"There's a striking difference between the number of men and women in the intensive care unit, and men are clearly doing worse," said Dr. Sara Ghandehari, a pulmonologist at Cedars-Sinai in Los Angeles.

She said 75 percent of Cedars-Sinai's Covid-19 patients on ventilators are men.

Dr. Ghandehari said pregnant women, who have high levels of estrogen and progesterone, tend to have mild symptoms.