Pristiq Vs Effexor: Understanding the differences and similarities between these antidepressants


Depression is a common mental disorder affecting millions of people worldwide. According to the World Health Organization, depression is the leading cause of disability globally, and it disproportionately affects women. Although various treatments are available, antidepressants are the most commonly prescribed medications for depression. Pristiq and Effexor are two commonly prescribed antidepressants that belong to the class of serotonin-norepinephrine reuptake inhibitors (SNRIs). In this article, we will explore the differences and similarities between these two antidepressants to help patients make informed decisions about their treatment options.

What are Pristiq and Effexor?

Pristiq (Desvenlafaxine) and Effexor (Venlafaxine) are drugs commonly prescribed for treating MDD (major depressive disorder). Both Pristiq and Effexor act as SNRIs. They work by blocking the reuptake of both serotonin and norepinephrine, which helps to increase the levels of neurotransmitters in the brain.

What is SNRI?

The SNRI is a class of medication that affects neurotransmitters in the brain. These medications selectively block the reuptake of two neurotransmitters – serotonin and norepinephrine – to improve the availability of these brain chemicals in the nervous system.

What are the similarities between Pristiq and Effexor?

Both Pristiq and Effexor are SNRIs, which means they work similarly in the brain to increase levels of the neurotransmitters serotonin and norepinephrine to ease depression symptoms. They are both FDA approved to treat MDD.

What Is MDD?

MDD refers to Major Depressive Disorder, also known as clinical depression, which is a mental health disorder characterized by persistent feelings of sadness and loss of interest in activities that the person once found pleasurable.

What are the differences between Pristiq and Effexor?

While Pristiq and Effexor are similar, there are some differences between them that doctors consider when prescribing treatment.

Active Ingredient

The main difference between Pristiq and Effexor is their active ingredient. Pristiq contains desvenlafaxine, whereas Effexor contains venlafaxine. Desvenlafaxine is a derivative of venlafaxine, created to improve the tolerability and reduce side effects in patients.


Another significant difference is the half-life of these medications. Pristiq has a shorter half-life than Effexor, meaning it is eliminated from the body more quickly. Pristiq has a half-life of approximately eleven hours, whereas Effexor has a half-life of approximately five hours. This means that Pristiq generally stays in the body for a shorter amount of time, while Effexor can remain in the body for longer.


Due to the difference in half-life, the dosage of Pristiq and Effexor is different. The recommended dose for Pristiq is 50 mg daily, whereas the recommended dose for Effexor is 75 mg or 150 mg per day. However, it is crucial to speak to a doctor to determine the optimal dose for each individual patient.

Side effects

Pristiq and Effexor can cause several side effects, but the side effects can differ between the two. Both medications can cause similar side effects such as nausea, vomiting, and dry mouth. However, Pristiq has a lower incidence of side effects compared to Effexor. Pristiq does not cause sexual dysfunction, whereas Effexor can affect sexual function.


There is also a price difference between Pristiq and Effexor, with Pristiq being more expensive than Effexor. In Australia, the listed PBS cost for one month’s supply of Pristiq is $41.30 for 50 mg and $57.50 for 100 mg. On the other hand, a one-month supply of Effexor is listed at $6.60 and $10.00 for the 75 mg and 150 mg tablets, respectively. However, the cost may vary based on the pharmacy and the location.

Which is better: Pristiq or Effexor?

Pristiq and Effexor are both effective antidepressants used to treat depression. However, the preference of one over the other depends on several factors.

For patients concerned about side effects, Pristiq may be a better option due to its lower incidence of sexual dysfunction and other side effects. For those concerned with dosing convenience, Effexor may present a better option since it requires a lower dosage and less frequent dosing, given its longer half-life. However, some individuals may experience better relief with Effexor than Pristiq, and vice versa. Therefore, it is essential to consult with a doctor or mental health professional to determine which antidepressant is most suitable for each individual patient.


Depression is a debilitating mental health disorder that requires appropriate treatment. Pristiq and Effexor are both effective antidepressants that belong to the SNRI class, which work by blocking the reuptake of serotonin and norepinephrine to increase their availability in the brain. While both medications are used to treat MDD, they differ in their active ingredient, half-life, dosage, side effects, and price. Furthermore, there is no conclusive evidence to determine which medication is superior, as the individual patient’s response to medication varies. It is crucial to consult with a doctor to determine the best treatment options, including medication and other therapy methods.


FAQs About Pristiq Vs Effexor

1. What are Pristiq and Effexor, and how do they differ?

Pristiq and Effexor are both medications prescribed to treat depression and anxiety disorders. They belong to a class of drugs called serotonin-norepinephrine reuptake inhibitors (SNRIs), which work by increasing the levels of neurotransmitters in the brain that regulate mood. However, Pristiq and Effexor differ in terms of their active ingredients and dosages. Pristiq contains desvenlafaxine, while Effexor contains venlafaxine. Also, Pristiq has a higher potency than Effexor, meaning that a lower dosage of Pristiq may have the same effect as a higher dosage of Effexor.

2. What are the common side effects of both medications?

Both Pristiq and Effexor have similar side effects, which may include dizziness, dry mouth, nausea, headache, sweating, and constipation. These side effects are usually mild and may go away over time as your body adjusts to the medication. However, some people may experience more serious side effects that require medical attention, such as allergic reactions, seizures, or suicidal thoughts. If you experience any of these symptoms, you should contact your healthcare provider immediately.

3. Can I switch from Pristiq to Effexor or vice versa?

In some cases, your healthcare provider may recommend switching from one medication to another if you experience intolerable side effects or if your symptoms are not improving with your current medication. However, it is important to do this under the guidance of your doctor, who can help you safely taper off one medication and start the other. Also, switching from Pristiq to Effexor or vice versa may affect the dosage and duration of treatment, so it is essential to follow your doctor’s instructions closely.


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2. Ghosal, S., & Humberstone, V. (2008). Is desvenlafaxine a better choice than venlafaxine for treating depression? The Psychiatrist, 32(11), 424-426. doi: 10.1192/pb.bp.107.019968

3. Lu, D., D’Agostino, D., Luo, Q., Rosenfeld, J., & Seeger, J. (2013). A systematic review comparing desvenlafaxine with venlafaxine in the treatment of major depressive disorder. Annals of Pharmacotherapy, 47(5), 656-665. doi: 10.1177/1060028013485287