In the 1940s, experiments showed that major depression can be relieved by injecting testosterone into men with low levels of that hormone. The treatment never caught on because the shots are painful, and effective antidepressant drugs started coming to market. More recently, however, testosterone patches and gels became available. In June 2000, the United States Food and Drug Administration approved a new form of gel for treating muscle loss, decreased sex drive, lack of energy, and other symptoms of so-called hypogonadism, or underactivity of the testes. Harrison Pope, a Harvard professor of psychiatry, wondered if the gel might also help males with the combination of low testosterone and depression not treated successfully with drugs. He asked for and received a grant from Unimed Pharmaceuticals Corp., which makes a testosterone supplement known as AndroGel. At McLean Hospital, a private psychiatric facility affiliated with Harvard Medical School, 12 men received small packets containing 2.5 grams of AndroGel. Another 10 subjects received identical packets containing a dummy, or placebo substance. By the end of the experiment, Pope found a significant improvement in mood among those taking testosterone compared with those using the dummy rub.