Which of the following best describes side effects?

Side effects are defined as effects of a medication that occur in addition to the desired therapeutic outcomes. These effects can be unwanted or unexpected reactions that may or may not require medical attention. When a patient takes a medication, the primary goal is often to achieve a specific therapeutic effect, but other physiological changes can occur as well, which constitute side effects.

The choice that describes side effects as "effects distinct from the desired outcome" accurately encapsulates this definition. It highlights the notion that while the drug may be effective in treating the primary condition, it may also cause other effects that are secondary and possibly undesirable.

Other options do not correctly define side effects. Benefits that enhance drug efficacy suggest a positive or beneficial effect, which does not align with the typical understanding of side effects as being unwanted. Adverse reactions that improve patient outcomes contradict the nature of side effects, as adverse reactions are generally detrimental. Lastly, symptoms indicating treatment is effective would more accurately describe indications that a medication is working, rather than side effects, which are usually negative experiences associated with the medication's use.