Duloxetine vs Venlafaxine: what is the difference?

How they differ

Both are SNRIs, blocking the reuptake of serotonin and norepinephrine rather than serotonin alone, and they weight the two differently. Venlafaxine is strongly serotonergic at lower amounts and only recruits norepinephrine as the amount rises, so its character changes across its range. Duloxetine hits both from the start, which is part of why it is used for nerve pain and fibromyalgia as well as for depression. Venlafaxine has a notably short half-life and produces a well-known discontinuation syndrome when stopped abruptly; duloxetine is somewhat gentler on that front. Structurally duloxetine carries a thiophene ring and a naphthalene ether at 297.4, and venlafaxine is a simpler phenol ether at 277.4.

Side by side

Common questions

What is the difference between Duloxetine and Venlafaxine?

Both are SNRIs, blocking the reuptake of serotonin and norepinephrine rather than serotonin alone, and they weight the two differently. Venlafaxine is strongly serotonergic at lower amounts and only recruits norepinephrine as the amount rises, so its character changes across its range. Duloxetine hits both from the start, which is part of why it is used for nerve pain and fibromyalgia as well as for depression.

Is Duloxetine bigger than Venlafaxine?

Duloxetine is the heavier molecule, 297.4 g/mol against 277.4 g/mol for Venlafaxine. Duloxetine is C18H19NOS and Venlafaxine is C17H27NO2.