Heartburn drug could ease painful sun sensitivity
NCT ID NCT05020184
First seen Jun 27, 2026 · Last updated Jun 30, 2026 · Updated 2 times
Summary
This Phase 2 trial tested whether oral cimetidine (Tagamet), a common heartburn drug, can reduce light sensitivity in people with erythropoietic protoporphyria (EPP) and X-linked protoporphyria (XLP). These genetic conditions cause severe pain from sunlight exposure. The study enrolled 26 participants who took cimetidine or a placebo twice daily for several weeks. Researchers measured changes in protoporphyrin levels, time to pain symptoms in sunlight, and quality of life.
What this could mean
Our plain-language read of the trial. This is informational only — not medical advice or a prediction.
- Active substance
- cimetidine (Tagamet)
- What this could lead to
- If it works, this could point toward a treatment to reduce painful light sensitivity in people with protoporphyria.
- What could go wrong
- This is a small Phase 2 trial with only 26 participants, so results may not apply to everyone. The drug may not lower protoporphyrin levels enough to improve symptoms.
This is an AI summary of the original study and may miss details. Read our disclaimer.
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Conditions
The condition(s) this trial relates to.
As listed by the trial registrant
The condition terms exactly as the trial's registrant entered them.
Contacts and locations
Locations
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Atrium Health Wake Forest Baptist Medical Center
Winston-Salem, North Carolina, 27157, United States
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Massachusetts General Hospital
Boston, Massachusetts, 02114, United States
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University of Texas Medical Branch
Galveston, Texas, 77555, United States
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