More than 1,300 men who say they have suffered major health problems, including heart attacks and strokes, after taking testosterone replacement drugs are banding together to sue major drugmakers over these effects. The men said they were misled by drugs companies’ marketing to take the hormones for a condition they claim companies made up.

Low testosterone can be a genuine medical condition if caused by medical disorders in the testicles, pituitary gland or brain, according to the Food and Drug Administration. This particular condition is known as hypogonadism, and in these cases, testosterone is approved as replacement therapy. But, the agency noted, it has “become aware that testosterone is being used extensively in attempts to relieve symptoms in men who have low testosterone for no apparent reason other than aging. The benefits and safety of this use have not been established.”

The men in the suit, which is underway in a district court in Illinois, are suing pharmaceutical companies AbbVie, Auxilium, Lilly, Watson, Endo and Pfizer, according to a press release by one of the law firms involved. The suit alleges that these companies marketed the condition “Low T,” alongside their testosterone products, by describing symptoms that are often associated with aging.

What I haven’t seen before is companies inventing a fake disease,” Ron Johnson, a lawyer in one of the cases, said, Forbes reported. “There’s no such thing as that.”

The copyright for the website belongs to AbbVie. “Reduced Sex Drive? Decreased Energy?” one of the slides on the homepage asks viewers. “Low testosterone, or Low T, is a medical condition ... and can cause symptoms such as: reduced sex drive, reduced energy, and sexual dysfunction, among others,” it says. “If you feel you’re experiencing the signs and/or symptoms of Low T, talk to your doctor to learn more about all the signs and symptoms of Low T and see if you should be tested.”

One plaintiff, Bob Cripe, blamed AndroGel, a testosterone gel made by AbbVie, for a stroke that left him partially paralyzed at the age of 46. He began taking the gel one week before his stroke.