Which of the following is a common side effect of medications?

Nausea is a well-documented common side effect of various medications. Many drugs, particularly those affecting the gastrointestinal system, can induce feelings of queasiness or discomfort in the stomach, which leads to nausea. This occurs due to the way certain medications interact with the body, often irritating the stomach lining or affecting gastrointestinal motility.

In contrast, the other options are not typically recognized as common side effects of medications. Increased energy levels and improved metabolism might occur due to specific types of medications, such as stimulants or those that impact hormonal balance, but they are not generalized side effects. Similarly, clearer skin may result from specific treatments, such as those for acne, but it is not commonly reported as a side effect of medications in general. Understanding these distinctions helps in recognizing the typical experiences associated with drug therapies in various populations.