Sales of Monster Energy rose 9 percent in April and May compared with a year ago, despite recent headlines questioning the drink’s safety, according to The Wall Street Journal.

In May, Monster Beverage Corp. filed a lawsuit to stop the San Francisco City Attorney’s office from trying to force the company to limit serving sizes of its energy drinks, as well as its marketing. Last fall, San Francisco City Attorney Dennis Herrera began an investigation into possible violations of California law involved in Monster’s marketing of energy drinks to children.

In March, Monster Energy agreed to market its drinks as beverages, instead of dietary supplements. The company’s decision comes after 18 public health experts asked the Food and Drug Administration (FDA) to restrict caffeine content in energy drinks. The company’s products will not change, but their label will soon include the amount of caffeine in each can.

Monster Energy has been implicated in the deaths of five people. In one case, a 14-year-old girl reportedly died of cardiac arrhythmia after consuming two 24-ounce Monster Energy drinks. Energy drink manufacturers say their products are safe. Monster Energy says its product contains significantly less caffeine than coffee, the article notes.

Under federal law, manufacturers of dietary supplements are required to notify the FDA of any adverse events linked to their products. Manufacturers of food or beverages are not required to do so.