What happens if you miss a dose of Aminolevulinic acid?
Last updated September 7, 2026.
Aminolevulinic acid is not a daily medicine you dose at home, so a missed dose almost always means a missed appointment or a missed pre-surgery timing window rather than a skipped pill. The topical forms, Levulan Kerastick and Ameluz, are applied by a clinician for actinic keratosis and then activated with a light source at the same visit or a set number of hours later, so skipping either step means the treatment has to be rescheduled from the start. Gleolan oral solution is a single dose taken about 3 hours before anesthesia for brain tumor surgery, and if that timing slips the surgical team needs to know so they can decide whether to adjust or postpone. There is no catch-up dose and no reason to double anything, since a second dose adds light sensitivity without adding benefit. If you already received a dose, keep your skin and eyes out of bright sunlight and strong indoor light for about 40 hours, because ordinary sunscreen does not block the visible light that triggers the reaction. Put the light-activation visit in your calendar with a reminder, since that appointment is the part people most often lose track of.
What to do
- Call the clinic, not the pharmacy: A missed aminolevulinic acid appointment is rescheduled by the dermatology or surgical office that administers it.
- Protect the light-activation step: If your treatment uses a separate blue light or red light visit, keep that appointment, because the drug does nothing useful without it.
- Flag pre-surgery timing changes: Tell the surgical team the exact time you took Gleolan if your operation is delayed or moved earlier.
- Skip the catch-up dose: Do not take or apply a replacement dose on your own and do not double up, since extra drug only adds light sensitivity.
- Stay out of bright light for 40 hours: Sunscreen does not block the visible light that causes the reaction, so use clothing, hats, and shade instead.
- Get seen for a strong reaction: Call your clinician for severe burning, blistering, swelling that spreads, or eye pain after a treated area is exposed to light.
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