Stand Up for Science traces Prozac’s accidental path from Benadryl

Stand Up for Science says the latest Traces Thursday installment looks at how an allergy drug helped inspire Prozac, the first SSRI approved by the FDA in 1987. The series uses the story to argue that basic research and long timelines are essential to medical breakthroughs.

Why it matters: - The Prozac story shows how a common side effect can lead to a major advance in depression treatment. - The case also highlights why basic science, clinical testing, and long-term funding matter for drugs that affect the brain. - Stand Up for Science says the example is timely amid debate over federal science funding.

What happened: - Stand Up for Science released the ninth installment of its weekly “Traces Thursday” series on October 23, 2026. - The new installment, “Antihistamines, antidepressants and brain chemistry,” follows the historical path from Benadryl to Prozac. - The series is published on the Science Fight Club Substack each Thursday.

The details: - Benadryl, or diphenhydramine, was discovered in 1943. - Researchers observed that the drug could cause drowsiness and ease anxiety in some people, beyond its allergy-relief effects. - Scientists later found that diphenhydramine affects serotonin, the chemical messenger nerve cells use to communicate. - The drug slows serotonin recycling, which lets the calming signal last longer. - Eli Lilly and Company then asked whether a compound could be built to target serotonin more directly and avoid Benadryl’s other effects. - Eli Lilly and Company created a series of molecules modeled on Benadryl and tested them in brain tissue in the lab. - One compound stood out: fluoxetine, first made in 1972. - After additional research and clinical trials, the FDA approved fluoxetine as Prozac in 1987. - Prozac became the first selective serotonin reuptake inhibitor, or SSRI. - Dr. Jeremy Berg said Prozac’s success opened the door to later antidepressants including Zoloft, Paxil, and Lexapro.

Between the lines: - Berg’s point is that major medicines often emerge from curiosity and chance observations, not just direct design. - The series frames drug discovery as a long process that can span far beyond a single grant cycle or presidential administration. - The message also serves as an argument for sustained investment in basic and biomedical research.

What’s next: - Stand Up for Science says Traces Thursday will continue weekly until the planned 12-part series is complete. - Berg is available for comment. - The organization will keep publishing the series on the Science Fight Club Substack each Thursday.

The bottom line: - A side effect of an allergy pill helped point researchers toward a depression drug that changed psychiatric care. The organization is using that history to press the case for steady science funding.