But I'm not more aggressive—a behavior change often tied to testosterone. That's not surprising to Robert Sapolsky, ., a neuroendocrinologist at Stanford University and a leading researcher on stress and behavior. "It's really not the case that testosterone 'causes' aggressive behavior," he says. "Instead, it makes the brain more sensitive to social cues that trigger aggression. And in support of that, a guy's testosterone level isn't a very good predictor of how likely he is to be aggressive."
The start of the AndroGel court proceedings is a thorn in the side of AbbVie, which is facing a host of challenges to some of its biggest blockbusters. Sales of its top-selling arthritis remedy Humira did jump 23% year-over-year in the first quarter to $ billion, but the company is facing biosimilar competition overseas that’s hampering its growth, and biosimilars are on their way in the . Meanwhile, sales of its hepatitis C combo Viekira Pak fell 36% to $263 million during the quarter, as AbbVie struggles to compete for market share against Gilead Sciences’ Harvoni.