Photodynamic Therapy

Compare To Other Treatments

Photodynamic therapy sessions are typically done in a medical setting under the supervision of a dermatologist. It is a 2-step procedure. The first step involves applying a photosensitizing agent onto the skin. Once the skin has absorbed the photosensitizing agent, the skin is then illuminated with a light or laser device. 

Dosing information:

The frequency and duration of photodynamic therapy may vary, but series of 1 to 5 sessions performed once weekly or once every other week are typical. 

  • Who is it for?

    • Gender:
      • Males and females
    • Severity of acne:
      • Mild to severe
    • Age:
      • Children of 12 years and older, adolescents, and adults
    • Other:
      Photodynamic therapy is one of the major alternative acne treatments for pregnant or lactating females

Photodynamic therapy may be a worthwhile alternative for people with severe acne who would prefer to avoid isotretinoin. 

Important! Any form of light treatment, including photodynamic therapy, may reduce your levels of folic acid, so be sure to talk to your doctor before you start photodynamic therapy.

How to use it:

Photodynamic therapy is usually performed in a medical setting. First, a doctor or a trained nurse will cleanse your skin to prepare it for the procedure. Then, she will apply a topical photosensitizing agent such as aminolevulenic acid (ALA), methyl aminolevulenic acid (MAL), or indole-3-acetic acid (IAA) on the area of skin that will be treated. A photosensitizing agent will increase your skin’s sensitivity to light and enhance the effects of the treatment.  

The photosensitizing agent will have to sit on your skin for some time, ranging from 15 minutes to 3 hours, but sometimes longer. This time is needed for the photosensitizing agent to get absorbed properly. It is normal if you feel some pain at this point. If your doctor wants you to leave it on for a longer period, you might be asked to go home and return when it’s time. 

Next, you will receive the light-based treatment. This will involve a lamp or a laser illuminating the treated area for about 10 to 45 minutes. Photodynamic treatment may involve using red light, blue light, mixed blue-red light, green light, intense pulsed light, LED light, fractional laser, or pulsed dye laser. Many people say photodynamic therapy is really painful and may require a topical anesthetic. 

After the procedure, the treated skin will be covered by a dressing that you should not remove until your doctor instructs you to do so–usually, until the next day. Keep the dressing dry. Once you remove the dressing, you can continue your bathing routing, but remember to gently pat the treated skin dry. 

Photodynamic therapy will temporarily make your skin very sensitive to light. Avoid sunlight completely for the first 48 hours after the procedure. Applying sunscreen will not be enough in during this period to protect your skin. After 48 hours, follow your doctor’s instructions for home care.

Be aware of:

  • Before starting photodynamic therapy, inform your doctor if you have done dermabrasion, microdermabrasion, chemical peeling, or any form of light treatment, including light therapy, photodynamic therapy, and laser resurfacing in the past. 
  • Before starting photodynamic therapy, tell your doctor if you have ever developed keloid (raised) scars.
  • Before starting photodynamic therapy, inform your doctor if you suffer from an autoimmune disease (e.g. rheumatoid arthritis, lupus)
  • Before starting photodynamic therapy, be sure to tell your doctor about any prescription and non-prescription medications, vitamins, nutritional supplements, and herbal products you are using/taking or have used/taken. Mention them even if it seems irrelevant to you and even if you haven’t taken these for a while.
  • Before starting photodynamic therapy, let your doctor know if you have or had cold sores. 
  • In many people, the skin contiunues to clear after the treatment is discontinued. You will likely see the best results several weeks after the final session. 
  • Before starting photodynamic therapy, inform your doctor if you are sensitive to light, sunburn easily, or are allergic to a photosensitizing agent. 
  • If you consider photodynamic therapy and are pregnant or are planning to become pregnant, talk to your physician about photodynamic therapy during pregnancy.
  • If you consider photodynamic therapy and are breastfeeding, talk to your physician about photodynamic therapy during this period.
  • You can continue your regular diet unless your physician recommends otherwise.
  • Photodynamic therapy is usually not covered by the insurance. 

Drug interactions: 

Inform your physician or pharmacist about all the prescription and nonprescription medications, vitamins, nutritional supplements, and herbal products you are taking or plan to take before your first photodynamic therapy session. Tell your doctor if you have taken isotretinoin, oral antibiotics, oral contraceptives, steroids, or NSAIDs within the last several months because these medications may render your skin more sensitive to light. In the case of isotretinoin, if you have taken it within the past year, you may be advised against photodynamic therapy.

  1. (2018). Lasers and lights: How well do they treat acne? [online] Available at: [Accessed 07 July. 2019].
  2. (2014). Photodynamic therapy (PDT) [online] Available at: [Accessed 07 July. 2019].
  3. Morton, C. et al. European Dermatology Forum Guidelines on topical photodynamic therapy. European Journal of Dermatology 25, 296–311 (2015).