In ads on Google, Facebook and elsewhere, testosterone telemedicine websites may promise a quick fix for sluggishness and low libido in men. But evidence for that is lacking, physicians said, and the midlife malaise for which testosterone is being touted as a solution is more likely caused by chronic medical conditions, poor diet or a sedentary lifestyle. In fact, doctors urge caution — and the FDA recommends that all testosterone supplements carry a warning that they may increase the risk