Prozac & Diet Pills

If you want to use a diet pill to lose weight but are taking Prozac, check with your doctor to make sure your pills don’t have ingredients that will cause a dangerous interaction with your medication. Diet pill formulations often feature a number of herbs, many of which may be contraindicated for Prozac. You should not combine Prozac with common diet pill ingredients like gotu kola, ginkgo biloba, stinging nettle and goldenseal, for example.

Is This an Emergency?

If you are experiencing serious medical symptoms, seek emergency treatment immediately.


Prozac is the brand name for the drug fluoxetine. Your doctor may prescribe it to treat depression, an eating disorder, obsessive-compulsive disorder or panic attacks. Fluoxetine also may be prescribed to relieve premenstrual dysphoric disorder symptoms like irritability, mood swings, bloating and breast tenderness.

Serotonin Syndrome

Prozac is in a class of medicines called selective serotonin reuptake inhibitors, or SSRIs. This medicine works by increasing your serotonin levels. Taking it with some herbs, including ginkgo biloba, can increase your serotonin levels to a dangerous level and induce serotonin syndrome. This is a potentially fatal condition. Symptoms can appear within minutes to hours. They include rapid heartbeat, hallucinations, increased body temperature, agitation, loss of coordination, overactive reflexes, rapid blood pressure changes, nausea and vomiting and diarrhea. This condition can cause severe muscle breakdown and kidney damage. It requires immediate medical attention.

Depression and Sedation

Taking Prozac with common diet pill ingredients gotu kola, goldenseal or stinging nettle can cause excessive sedation and mental impairment and depression, according to “The Essential Herb-Drug-Vitamin Interaction Guide,” by George T. Grossberg and Barry Fox. Taking Prozac alone also may alter your mental state. You may even become suicidal, according to PubMed Health. This risk factor is higher when you begin treatment and when your dosage is altered. Seek immediate medical attention if you experience new or worsening depression, begin to think about harming or killing yourself, have panic attacks or extreme worry, cannot fall or stay asleep, experience aggressive behavior, begin acting without thinking, have severe restlessness or feel frenzied or an abnormal level of excitement.

Expert Insight

Using Prozac with many other herbs and supplements is contraindicated. It’s especially important to check with a doctor before using St. John’s wort or tryptophan with Prozac, according to PubMed Health. Other herbs that interact with Prozac include catnip, ergot, kava kava, lemon balm, sassafras, valerian, and nerve root. Also know you risk ingesting undeclared ingredients when you take diet pill formulations. For example, diet pills on the market may contain phenytoin, a prescription antiseizure drug that interacts with Prozac.