Sold under brand names such as Prozac and Sarafem, fluoxetine is a selective serotonin reuptake inhibitor (SSRI) antidepressant that has seen massive commercial success.
Fluoxetine has been used since 1986 and has achieved such a high degree of usage that it’s largely responsible for the breakthrough of antidepressant medications into the public consciousness.
However, as research piles up, fluoxetine’s adverse effects are becoming clearer. We now know that fluoxetine can cause erectile dysfunction (ED) and other sexual problems.
We’ll explore the realities of fluoxetine-induced sexual dysfunction and what can be done about it.
Sexual side effects are linked to antidepressants in general, but, according to the literature, fluoxetine appears to be among the worst offenders.
Common adverse effects involving sexual dysfunction and SSRI antidepressants are erectile dysfunction, lack of vaginal lubrication, anorgasmia, and decreased sex drive. Early clinical trials suggested these effects were rare but more recent findings show they’re actually quite common — certain studies find at least one form of sexual dysfunction in roughly 70% of all cases .
The causes for fluoxetine-induced erectile dysfunction are not well understood — it’s theorized the SSRI’s calming effects can dampen sexual libido and interrupt the hormones that cause the body to prepare for sexual activity.
Recent findings regarding fluoxetine and sexual dysfunction give even more cause for concern. In June 2019, Pharmacovigilance Risk Assessment Committee of the European Medicines Agency publicly concluded that it had found a possible causal association between SSRIs and long-lasting sexual dysfunction that persists even after SSRI use is discontinued.
If you’re concerned about ED — or any of the other sexual adverse effects related to fluoxetine — your best bet is likely to switch your antidepressant medication.
This is a decision that should be discussed with your doctor, but we can recommend some antidepressants known to elicit fewer sexual side effects than SSRIs.
According to the Mayo Clinic, the antidepressants with the lowest rates of sexual dysfunction include:
- Bupropion (Wellbutrin XL, Wellbutrin SR)
- Mirtazapine (Remeron)
- Vilazodone (Viibryd)
- Vortioxetine (Trintellix)
However, if you decide that switching to a different antidepressant is not the right move, there are always other options you could try:
- Wait a couple of weeks: If you’re just starting out on fluoxetine, give it a couple of weeks before you become unduly concerned. It’s quite normal for side effects to be more prevalent at the start of treatment.
- Try Yohimbe: Studies reveal that yohimbine, an α2-adrenergic receptor antagonist, can successfully treat fluoxetine-induced ED . However, this needs to be discussed with your doctor. Never mix supplements with prescription medication without a doctor’s okay.
- Adjust your dose: Adverse effects in prescription medications are usually dose-dependent. As such, reducing the dose might be enough to bring ED and other side effects under control.
- Consider a PED5 inhibitor: ED medications like sildenafil (Viagra), tadalafil (Cialis) or vardenafil (Levitra, Staxyn) are safe and effective. Talk to your doctor about which option is best for you.
Fluoxetine is a certain type of antidepressant known as an SSRI.
- Major Depressive Disorder (MDD)
- Obsessive Compulsive Disorder (OCD)
- Bulimia Nervosa
- Panic Disorder, with or without agoraphobia
- Acute depressive episodes associated with bipolar disorder and treatment-resistant depression (in combination with the antipsychotic olanzapine)
- Alcohol dependence
- Binge eating disorder
- Post Traumatic Stress Disorder (PTSD)
- Premature ejaculation
- Premenstrual Dysphoric Disorder
The large number of off-label uses for fluoxetine show how important it is in the medical community and how much research and interest this compound has attracted.
Fluoxetine’s effects are achieved by altering the neurochemistry of the brain. It does this by targeting and mediating neurotransmitters, the chemical messengers that carry signals across the brain and interact with a vast swath of receptors.
It’s theorized that depression is primarily caused by chemical imbalances in the brain. These supposed “chemicals” actually refer to neurotransmitters like dopamine, epinephrine, and serotonin.
By interacting with neurotransmitters in the brain and central nervous system, antidepressants like fluoxetine are thought to correct the fundamental imbalances that lead to depression.
For a long time, the theory that depression was caused by a lack of serotonin in the brain was a widely held belief in the medical community. However, the validity of this belief, and thus the validity of SSRIs, has recently begun to come under question for a variety of reasons. We won’t dive into this matter, though, as it’s outside the scope of this article.
According to the FDA, fluoxetine can cause the following adverse effects:
- Abnormal dreams
- Abnormal ejaculation
- Decreased libido
- Dry Mouth
- Flu syndrome
As an SSRI, fluoxetine increases serotonin levels in the brain. Serotonin acts as a hormone but is actually one of the body’s primary neurotransmitters (signaling molecules) and regulates a number of functions such as mood, digestion, nausea, and sleep.
SSRIs increase the available levels of serotonin in the brain by disrupting a process known as reuptake. Reuptake is the pathway by which serotonin molecules are cleared from the synaptic cleft, the space between neurons, and are reabsorbed back into the presynaptic neuron, where they’re no longer pharmacologically active.
A molecule known as a transporter protein binds to serotonin molecules and, as its name suggests, transports them out of the synaptic cleft.
SSRIs work by inhibiting transporter proteins, impeding their function. This leads to increased levels of serotonin in the brain, increasing serotonin neurotransmission — when the axon terminal of a neuron (the presynaptic neuron) releases neurotransmitters, which bind to and react with the receptors on the dendrites of another neuron.
Recent research on the link between fluoxetine and sexual dysfunction is not pretty. Not only is the problem more prevalent than it seemed to be, but there is also evidence for long-term effects that persist even after stopping SSRI treatment.
ED and low sex drive often cause men to discontinue fluoxetine treatment, but, unfortunately, this often implies the return of depressive symptoms. No one wants to choose between being free of depression and having a healthy sex life.
As such, we recommend choosing an antidepressant with fewer incidences of sexual dysfunction or using a PDE-5 inhibitor. However, patients should be aware that these are extremely delicate decisions, and don’t take action without a doctor’s consultation.
- Clark, M. S., Jansen, K., Bresnahan, M., & Replogle, W. H. (2013). Q/How do antidepressants affect sexual function?. Journal of Family Practice, 62(11), 660-662.
- Jacobsen, F. M. (1992). Fluoxetine-induced sexual dysfunction and an open trial of yohimbine. The Journal of clinical psychiatry.
- Stone, K. J., Viera, A. J., & Parman, C. L. (2003). Off-label applications for SSRIs. American Family Physician, 68(3), 498-504.
- Rezaei, H. G., Shahverdi, E., Ebrahimi, S., & Dehghani, K. (2015). The Therapeutic Effects of Tramadol and Fluoxetine in Premature Ejaculation: A Randomized Clinical Trial. Thrita, 4(3).