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Short answer What to know about the light-protection window Common questions Related questions Sources**Aminolevulinic acid itself leaves your bloodstream within about a day, but the light-sensitizing compound it creates keeps you sensitive to bright light for roughly 40 to 48 hours after treatment.**
The drug has a short half-life, so blood levels drop quickly, but your cells convert it into protoporphyrin IX, which is what makes skin and eyes react to light. That compound peaks within several hours and fades over about two days. The oral form used during brain tumor surgery and the topical forms used on actinic keratosis both carry a 40 to 48 hour light precaution. Reduced kidney or liver function, repeat doses, and a larger treated area can stretch that window. Plan to stay indoors away from windows, skip bright task lighting, and cover treated skin with clothing and a wide brimmed hat if you must go out.
What to know about the light-protection window
Common questions
How long does Aminolevulinic acid stay in your system?
Aminolevulinic acid has a short half-life, roughly under an hour after an oral dose, so the drug itself is largely gone within a day. What matters more is protoporphyrin IX, the light-sensitive compound your cells make from it. That compound peaks a few hours after dosing and fades over about 48 hours. Labeling for the oral form used in brain surgery advises avoiding sunlight and bright indoor light for 48 hours. For the topical forms used on actinic keratosis, treated skin stays sensitive for about 40 to 48 hours. Kidney or liver problems and repeat dosing can extend that window, so follow the exact timing your care team gives you.