According to the search results, there are several prescription weight loss pills that are effective. The most effective weight loss pill available is Qsymia, which combines an adrenergic agonist with a neurostabilizer. Other effective prescription weight loss pills include semaglutide, liraglutide, naltrexone-bupropion, orlistat, and phentermine-topiramate. However, it is important to note that these pills should be used in addition to a healthy diet and exercise, and they are not suitable for everyone. Before taking any weight loss pill, it is important to consult with a healthcare provider to determine if it is safe and appropriate for you.