(S)-Venlafaxine is primarily used in the treatment of major depressive disorder (MDD), generalized anxiety disorder (GAD), social anxiety disorder, and panic disorder. It functions as a serotonin-norepinephrine reuptake inhibitor (SNRI), increasing the levels of these neurotransmitters in the brain, which helps improve mood and reduce anxiety.

In clinical practice, it is often prescribed when other antidepressants, such as SSRIs, have not been effective. It is also used off-label for conditions like obsessive-compulsive disorder (OCD), post-traumatic stress disorder (PTSD), and certain types of chronic pain, such as neuropathic pain.

The (S)-enantiomer is particularly noted for its potent inhibition of serotonin reuptake, making it a key component in managing symptoms of depression and anxiety. It is available in both immediate-release and extended-release formulations, allowing for flexible dosing based on patient needs.

Patients typically start with a low dose, which is gradually increased to minimize side effects such as nausea, dizziness, and insomnia. Regular monitoring is essential to ensure efficacy and manage any adverse effects.