Aminolevulinic Acid: Actinic Keratosis Care, Use, Side Effects
Last updated September 7, 2026.
**Aminolevulinic acid is a prescription photosensitizing agent, a porphyrin precursor used in photodynamic therapy for sun damaged skin and in fluorescence guided brain tumor surgery.** Your cells convert it into protoporphyrin IX, a light sensitive compound that builds up more in abnormal cells than in healthy ones. When a specific wavelength of light hits that buildup, the treated cells are destroyed, or the tumor tissue glows pink under a blue violet surgical microscope. The single most important safety point is light avoidance: your skin and eyes stay sensitive for 40 hours after a Levulan Kerastick application and for 48 hours after an oral Gleolan dose, so sunlight, tanning, and bright indoor light such as exam lamps or operating room lights can cause a stinging burn during that window.
What does it treat?
Aminolevulinic acid is used mainly for actinic keratoses, the rough, dry, scaly, sometimes tender spots that show up on chronically sun exposed skin and can turn into squamous cell carcinoma if left alone. The Levulan Kerastick 20 percent topical solution treats minimally to moderately thick actinic keratoses of the face, scalp, and upper extremities. Ameluz 10 percent gel treats mild to moderate actinic keratoses of the face and scalp, including field treatment of a whole sun damaged area rather than single spots. Gleolan is a different form, an oral solution given before surgery for suspected high grade glioma, so the neurosurgeon can see fluorescent tumor tissue in real time. There are no fixed dose combination pills; instead the drug is always paired with a matched light device, the BLU-U blue light for Levulan and the BF-RhodoLED red light lamp for Ameluz.
How do you take it?
You do not take this at home. A clinician applies the Levulan Kerastick solution directly to each lesion, then you return 14 to 18 hours later for blue light exposure of about 17 minutes, or for upper extremity lesions the solution sits under an occlusive dressing for 3 hours before the light. Ameluz gel is spread over the lesions plus a 5 mm margin, up to 2 grams of gel per session, covered for 3 hours, then treated with red light. One Kerastick applicator is used per treatment session, a Levulan treated site can be retreated after 8 weeks, and an Ameluz field can be retreated once after 3 months if spots remain. Gleolan is a single oral dose of 20 mg per kg of body weight dissolved in water and swallowed 3 hours, in a 2 to 4 hour window, before anesthesia, and your surgical team handles the timing and fasting instructions. There is no missed dose to make up, since every dose is scheduled around a light session or an operation, so if you cannot come in, call and reschedule instead of applying anything yourself. Call your doctor if pain, swelling, or crusting keeps getting worse after day 4, if a treated spot oozes yellow fluid or develops spreading redness, or if the area has not healed by about 4 weeks.
Side effects to know
- Common: Expect stinging or burning during the light exposure, then redness, swelling, scaling, crusting, and itching at treated spots that usually peak in the first few days and settle within 1 to 4 weeks, and with the oral form expect nausea, headache, and temporary color changes in urine.
- Serious: Stop light exposure and get urgent help for signs of an allergic reaction such as hives, swelling of the lips, face, or tongue, or trouble breathing, and for eye pain or vision changes after light treatment. Also seek care for a severe blistering burn on sun exposed skin during the photosensitive window, or, after an oral dose, for fainting, a rapid pulse, or lightheadedness that could signal low blood pressure.
Who should not take it?
Aminolevulinic acid is not for you if you have porphyria, a known allergy to porphyrins, or cutaneous photosensitivity to the treatment wavelength, and Ameluz also contains soy phosphatidylcholine, so tell your clinician about peanut or soy allergy. Talk with your doctor first if you have lupus or another photosensitive condition, liver or kidney disease, a bleeding or clotting problem, or an active skin infection or open wound in the treatment area. Many everyday medicines raise light sensitivity and should be reviewed before treatment, including doxycycline and other tetracyclines, fluoroquinolones, sulfonamides, thiazide diuretics, sulfonylureas, phenothiazines, griseofulvin, isotretinoin, and St. John's wort; with the oral form, avoid other photosensitizing drugs for 24 hours before and after the dose and be careful with drugs hard on the liver. There are no adequate data in pregnant or breastfeeding people, so current FDA labeling calls for weighing benefit against unknown risk with your clinician, and Ameluz specifically is not recommended in pregnancy. Alcohol does not interact directly with the topical forms, but skip it around the oral dose because it stresses the liver and because you will be heading into surgery.
When is it an emergency?
Call 911 if you collapse, faint, have chest pain, or have trouble breathing, or if your lips, tongue, or throat swell after treatment, which can mean anaphylaxis. Call Poison Control at 1-800-222-1222 right away if anyone swallows the topical solution or gel, if a child gets into it, or if too much of the oral solution is taken; overdose mainly means longer and more intense light sensitivity, plus nausea, vomiting, and possible low blood pressure. Go to an emergency room for eye pain, sudden blurred vision, or light sensitivity in the eyes after a light session, and for a large blistering burn that develops after sun exposure during your photosensitive window. Same day in person care is also right for spreading redness, warmth, pus, or fever from a treated area, which points to infection rather than normal healing.
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Common questions
What is the maximum amount I can get in one session?
Dosing is set by the product and applied in the clinic, not by you. One Levulan Kerastick applicator covers a single treatment session, and that site can be treated again after 8 weeks if spots remain. Ameluz is limited to 2 grams of gel per application, spread over the lesions plus a 5 mm margin, and the field can be retreated once after 3 months. The oral form, Gleolan, is a single dose of 20 mg per kg of body weight taken 3 hours before anesthesia, and it is not repeated for that surgery.
Can I drink alcohol around this treatment?
Alcohol does not interact directly with the topical solution or gel, so a normal drink is not a problem with skin treatment. Skip alcohol around the oral Gleolan dose, since that form is processed by the liver and can raise liver enzymes, and you will be going into surgery within hours. Your surgical team will also give you fasting rules that rule out alcohol the night before. If you drink daily or heavily, say so before treatment, because that changes liver monitoring.
Is aminolevulinic acid safe during pregnancy or breastfeeding?
There are no adequate studies in pregnant or breastfeeding people for any of these products, so FDA labeling leaves it as a benefit versus unknown risk decision with your clinician. Ameluz is specifically not recommended during pregnancy. Actinic keratosis treatment is rarely urgent, so most clinicians simply postpone photodynamic therapy until after pregnancy or nursing. Glioma surgery is a different situation, and the surgical team weighs the value of seeing tumor margins against the lack of data. Tell your doctor if you are pregnant, might be, or are breastfeeding before anything is applied or swallowed.
Do I need to take it with food, and what about sunscreen?
Food rules do not apply to the topical forms, since nothing is swallowed. For the oral Gleolan solution, the powder is dissolved in water and taken on the fasting schedule your surgical team gives you before anesthesia. Ordinary sunscreen is not enough protection during the light sensitive window because it does not block the visible wavelengths that activate this drug. Use physical barriers instead: a wide brim hat, long sleeves, gloves for hand treatments, and staying indoors with dim lighting for 40 hours after Levulan or 48 hours after Gleolan.
What are the signs of too much exposure or overdose?
The main sign is a burn: intense stinging, deep redness, swelling, and blistering on skin that got light during the sensitive window. Swallowing the topical solution or gel, or taking extra oral solution, can cause nausea, vomiting, lightheadedness from low blood pressure, and a much longer period of light sensitivity. Call Poison Control at 1-800-222-1222 for any swallowed or extra dose, even if the person feels fine. Call 911 for fainting, trouble breathing, or swelling of the face and throat.
Which of my medicines could cause a problem?
Tell your clinician about anything that raises light sensitivity, including doxycycline and other tetracyclines, fluoroquinolones like ciprofloxacin, sulfonamides, thiazide diuretics such as hydrochlorothiazide, sulfonylureas, phenothiazines, griseofulvin, isotretinoin, and St. John's wort. These can make the reaction stronger than expected. With the oral form, other photosensitizing drugs should be avoided for 24 hours before and after the dose, and drugs that stress the liver need review. Also mention topical steroids or retinoids you use on the treatment area, since they change how the skin absorbs the drug.