This medication conflict checker helps people with erythropoietic protoporphyria or X-linked protoporphyria find out if their current medicines could affect clinical trial eligibility. Select your medicines below to screen the active EPP trials for possible conflicts.
Most people with EPP take few prescription medicines for the disease itself, so the medicines that matter most in trial criteria are the EPP treatments: the Scenesse implant, an investigational drug from an earlier trial, and the over-the-counter and off-label products people try for light tolerance. Every trial publishes its own rules, and they differ, so the checker shows each trial's wording.
Scenesse (afamelanotide) implant
Scenesse — trials of new EPP drugs measure time in sunlight without pain, and a recent implant would blur the result, so they exclude people who had a Scenesse implant recently. APOLLO required a washout of at least 2 months from afamelanotide or dersimelagon and barred both during the study; INSPIRE excluded afamelanotide within 3 months; PATHWAY excludes any medicine that alters light sensitivity, naming afamelanotide, melanotan, beta-carotene and dersimelagon, within 90 days of the first dose. Clinuvel's US site also says Scenesse is not suitable for people in trials of other EPP treatments.
Investigational EPP drugs
bitopertin, dersimelagon, PORT-77, prior trial drugs — a trial will not take you while you are in another drug study, and each sets a washout after a previous investigational drug: INSPIRE required 12 weeks or 5 half-lives after any investigational agent such as bitopertin, and PATHWAY requires 120 days after bitopertin and 5 half-lives or 30 days after any other study drug. People who completed a bitopertin or dersimelagon trial are offered that drug's open-label extension (HELIOS for bitopertin, NCT05005975 for dersimelagon) by invitation. Disc Medicine's expanded access program is separate from its trials.
Light tolerance products
beta-carotene (Lumitene), cimetidine, antihistamines, vitamin D — beta-carotene and cimetidine are sometimes taken off label for EPP, and trials ask you to stop them well before screening so they do not confuse the sunlight diary: INSPIRE excluded cimetidine within 4 weeks and antioxidants such as beta-carotene, cysteine and pyridoxine within 4 weeks at doses the investigator thought could affect the endpoints, and PATHWAY excludes beta-carotene within 90 days. A placebo-controlled trial of cimetidine 800 mg twice daily found no difference from placebo in red cell protoporphyrin. Vitamin D was not named in these exclusions.
Liver and iron medicines
cholestyramine, ursodiol, iron supplements — cholestyramine is used in people with liver involvement to interrupt protoporphyrin recirculation, and iron is given when stores are low. Iron changes protoporphyrin readings, so APOLLO excluded anyone who started iron supplements or another anemia treatment within 1 month of screening, and PATHWAY excludes iron within 30 days of the first dose. Expect liver tests and iron studies at screening.
Liver involvement is the most common reason to be turned away
The Scenesse label trials enrolled adults without significant liver involvement, and the oral drug trials set liver limits too: INSPIRE excluded clinically significant hepatobiliary disease and AST, ALT or ALP at or above 2 times the upper limit of normal, PATHWAY requires AST and ALT under 3 times and bilirubin under 2 times the limit, and both APOLLO and PATHWAY exclude anyone who has had or is expected to need a liver transplant. If your liver enzymes are raised, ask whether a trial can still take you or whether an expanded access program fits better.
A conflict does not always mean you cannot join
Most medication rules in EPP trials are about timing. A Scenesse implant or a previous study drug may only need a washout, and a vitamin or supplement may only need a stable dose. The checker shows the trial's own wording and any washout it states; the study coordinator decides.
Age 12 and up is now common
APOLLO, INSPIRE (ages 12 to under 75), PATHWAY and the bitopertin expanded access program all take people aged 12 and up with EPP or XLP, while Scenesse is approved for adults only. Parents of teenagers should bring the red cell protoporphyrin result and the gene result to the first call, because trials require both.
Don't see your medication listed?
The checker covers the medicines most often named in EPP trial criteria. If yours is not in the list, we have not found it in the active EPP trials' exclusion criteria. Tell the study team about every medicine and supplement you take, including sunscreen or tanning products, when you contact them.
How the medication conflict checker works: This free tool helps people with EPP and XLP learn if their current medications could affect clinical trial eligibility. It scans the published eligibility criteria of every active EPP trial on ClinicalTrials.gov and highlights possible conflicts. EPP trials are few and small, so you may see only a handful of results. The most important eligibility factors are usually a confirmed diagnosis with protoporphyrin and gene results, age, liver and iron status and the time since your last Scenesse implant or study drug, rather than everyday medicines. Always confirm eligibility directly with the study team.
Across 1,853 open rare disease treatment trials, a third exclude people over a medication they commonly take. See which medications and diseases, in our September 2026 analysis.