By UTMB’s Jeff Temple: Question: Does using Fluoxetine for more than 20 years cause any serious damage or adverse effects? Answer: The short answer is “probably not.” The longer and more nuanced answer is that, while we cannot say definitively, most indications suggest that there is little to worry about in this regard. If taken as directed, selective serotonin reuptake inhibitors, or SSRIs, are generally considered safe, with little to no known long-term side effects. Those taking the medication can be further reassured that Fluoxetine (Prozac) has been around and studied the longest, so we are even more confident about its long-term safety profile.