Disclaimer: None of the information in this article constitutes medical advice, and is just the opinion of the writer(s). We recommend that patients follow their doctor’s guidance in regards to prescription medication.
Prozac is one of the most commonly-prescribed antidepressants in the U.S. and has been on the market since 1999. The generic version of the drug is called fluoxetine, and we’ll use these terms interchangeably throughout this article.
In this article we’ll review the medical research on Prozac to determine if it’s safe and effective for depression, obsessive-compulsive disorder (OCD), panic disorder and other uses that it’s approved by the Food and Drug Administration (FDA) in the U.S. to treat.
Does Prozac Work?
Prozac has been studied for its effects in treating a number of mental health disorders. The most commonly-prescribed use of Prozac is for depression.
Since Prozac was approved several decades ago, most of the research on the drug is not recent. A medical review published in the Annals of General Hospital Psychiatry journal examined the results from 87 individual clinical trials on Prozac for depression, with data on 9,087 patients.
The researchers concluded that Prozac was effective for treating depression from the first week of therapy. This doesn’t mean it was effective for all patients; just that it decreased patient depression scores on average to a statistically significant degree.
A fascinating and more recent animal study examined how living environment affected Prozac efficacy. The researchers found that the mice that received Prozac treatment in a supportive living environment had a reduction of their symptoms, while mice that received Prozac treatment in a stressful living environment had a worsening of their symptoms.
The study didn’t clearly define how the living environment was made to be “enriched” or stressful, but the results suggest that Prozac may be more effective in patients with a supportive and loving home environment.
Prozac is also proven effective for treating OCD. The linked clinical trial examined the effects of the drug on 265 OCD patients, and found that treatment “significantly decreased” their symptoms. The drug was more effective on a subcategory of OCD called “washers” (patients with a phobia of germs who excessively wash their hands) than a subcategory called “checkers” (patients who have to check through a list of items before completing their daily routines).
As referenced in the intro section, Prozac is also approved for use in panic disorder, and it appears to be effective for that use based on medical research. A clinical trial examined the effects of the drug on 25 patients with diagnosed panic disorder.
76% of the patients experienced a significant improvement in their symptoms. This was a small trial, and not double-blinded or placebo-controlled, so we find the results to be relatively weak.
Prozac is also approved for treatment of bulimia, and has been studied to this effect. A 1992 medical trial tested Prozac versus a placebo on 387 bulimic patients. Prozac use decreased the frequency of binge eating and vomiting episodes, and the 60 milligram (mg) per day dosage was found more effective than the 20 mg per day dosage.
There were secondary benefits in the bulimic patients on Prozac such as improvements in depression, carbohydrate craving and pathologic eating attitudes.
Clearly there is a significant amount of medical research backing the efficacy of Prozac for treating a variety of mental conditions. There is more research on its effectiveness for depression than other conditions.
How Does Prozac Work?
Prozac is an Selective Serotonin Reuptake Inhibitor (SSRI), which is the most common class of antidepressant medications.
These drugs minimize the reuptake of serotonin in the brain. Since serotonin is a neurotransmitter that influences mood and depression, artificially increasing its circulating levels by blocking reuptake is the mechanism of action targeted by Prozac.
Researchers still haven’t conclusively proven that low levels of serotonin in the brain are the cause of depression; we just know that this type of drug is effective on average for depressed patients.
In the future it’s likely that pharmaceutical depression treatment will be much more individualized, as it seems logically clear that one single neurotransmitter isn’t the cause of depression for all patients.
Prozac Side Effects
SSRIs do cause side effects in some patients, and Prozac is no exception.
A medical review of the side effects of Prozac found that the most common side effects were nausea, increased nerves and insomnia. The study authors showed that these side effects were actually more common in Prozac patients than with another class of antidepressants called tricyclic antidepressants. An example of a brand-name tricyclic antidepressant is Elavil.
Prozac is required by the FDA to publish a black box warning on their product label indicating that the drug may increase risk of suicidal thoughts and behaviors. This is unfortunately common for SSRI medications, and our recent Lexapro review article detailed how that brand was required to list the exact same warning.
Increased risk of suicidality will not affect most users of Prozac; it’s a rare side effect, but definitely one worth speaking with a doctor about, especially for patients with a family history of suicide.
Every patient’s dose may be different depending on their individual circumstances, but we can review the medical research on typical dosage of Prozac for depression.
The StatPearls resource page, which is the largest medical database, indicates that Prozac dosage is typically initiated at 20 mg per day. It can be broken into smaller doses taken throughout the day to minimize side effects. So a patient prone to nervousness may want to take a 10 mg dose in the morning and a 10 mg dose in the evening rather than one single 20 mg dose to decrease the risk of side effects.
Prozac has been studied, and proven safe on average, at doses up to 80 mg daily according to StatPearls. Typically a doctor will increase the dosage up to the safety limit if the patient isn’t responding to treatment.
So a depressed patient may start with the standard 20 mg dose, but if they’re not seeing any antidepressant effect after a few weeks their doctor may recommend that they up their dose to 40 mg and above.
Should I Take Prozac Generic?
The generic form of Prozac is called fluoxetine. These two terms refer to the exact same active ingredient; Prozac is just the branded version.
We typically recommend that patients speak with their doctor about the generic version of a drug, because it’s often cheaper and just as effective.
A medical review of generic versus branded drugs, published in the PLOS Medicine journal, found generic drugs to be just as effective for treating the stated health condition on average.
This makes logical sense, given that both generic drugs and branded drugs are the same chemical compound.
Does Prozac Affect Alcohol Consumption?
There’s some interesting research in regards to Prozac’s effect on alcohol consumption and desire to drink.
A clinical trial with an alcoholic population found that Prozac decreased desire to drink when the subjects were presented with a variety of alcoholic drinks. The drug at a dose of 60 mg/day also decreased drinks consumed by nearly 50%.
These results were mirrored in a separate clinical trial where depressed alcoholic patients on Prozac had improvement in depression scores and also decreased their alcohol intake throughout the course of the trial.
Based on the available research it seems as though Prozac may be an especially effective option for patients with both depression and substance abuse issues, and we recommend those patients to speak with their doctor about the research on Prozac and alcohol addiction.
Prozac Vs. Zoloft
Zoloft (generic name sertraline) is another popular SSRI antidepressant, and many patients are curious about which is more effective for treating depression.
Our sertraline reviews article documented how there have been medical trials directly comparing the two drugs, and that Zoloft performed better in those trials. Zoloft was also better-tolerated; causing fewer patients to drop out of the trial due to adverse effects.
A more recent medical review analyzed results from 5 individual trials comparing the two drugs. The researchers found that Zoloft was slightly more effective on average for treating depression, and was more effective to a statistically significant degree for treating severe depression.