Federal health officials on Tuesday approved the first prescription drug intended to treat women suffering from a lack of sexual desire. The daily pill, which acts on brain chemicals, followed a long, winding path to approval, including two previous rejections by the Food and Drug Administration. Here's a look at the history:

- Pre-2009: German drugmaker Boehringer Ingelheim studies its drug, known chemically as flibanserin, as a treatment for depression in men and women. The drug had little effect, but researchers noticed patients reported increased sexual desire, suggesting an alternate use.

- 2009: Boehringer submits the drug to the Food and Drug Administration for approval to treat female hypoactive sexual desire disorder, a condition described as emotional distress caused by a lack of sexual desire. The FDA had never approved a drug for that condition or any other female sexual disorders.

- June 2010: A panel of FDA advisers votes unanimously against the drug, saying its benefits are outweighed by its risks, including side effects like dizziness, fatigue and fainting.

- Late 2011: Boehringer abandons the drug and sells it to Sprout Pharmaceuticals, a small North Carolina company.

- March 2013: Sprout resubmits the drug to FDA with additional data showing its benefits using a new measurement technique.

- September 2013: The FDA rejects the drug a second time, saying its benefits are "numerically small" and still don't outweigh "substantial safety concerns."

- December 2013: Sprout files a formal dispute against the FDA, arguing the agency should approve the drug without any additional data.

- February 2014: The FDA responds by proposing Sprout conduct additional studies, including one examining flibanserin's effects on driving, because of its drowsiness side effect.

- February 2015: Sprout resubmits the drug to the FDA with the requested studies. At the same time, the company helps fund a campaign called Even the Score, which lobbies the FDA to approve sexual medicines for women.

- June 2015: A panel of FDA advisers votes 18-6 in favor of approving the drug, with safety restrictions.

- August 2015: The FDA approves flibanserin, branded Addyi, as the first drug to treat any type of female sexual dysfunction. The drug includes a black box warning about side effects.