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Types of Light Therapy · Light plus a medicine

Photodynamic therapy: light that activates a medicine.

In photodynamic therapy a topical medicine is applied, then activated by light. The best evidence we found is for actinic keratosis.

A clear glass dropper with a single droplet of pale translucent liquid catching soft red light (AI-generated illustration)

In short

  • Across 7 trials and 1,233 patients, PDT and cryotherapy cleared actinic keratosis similarly (risk ratio 1.02).1
  • Cosmetic outcome was better with PDT (74.62% versus 49.11%), but PDT caused significantly more burning and pain.1

01

Actinic keratosis

The meta-analysis found PDT and cryotherapy cleared lesions similarly. Cosmetic outcome was better with PDT, and PDT caused significantly more burning and pain. Cryotherapy caused more vesicles and blisters.1

02

Photoaging, scars and pigment

A review of 24 articles found LED-activated PDT with MAL or 5-ALA was associated with smoother texture, fewer rhytides and improved scars, but high-quality studies were scarce.2

What we could not confirm

The gaps, stated plainly.

  • Which medicine, light and timing is best for photoaging. The review notes that high-quality studies were scarce.
  • Whether PDT is better than other cosmetic treatments. We found no head-to-head comparison.

Questions

Common questions.

Is PDT better than cryotherapy for actinic keratosis?

Clearance was similar. Cosmetic outcome was better with PDT, 74.62% versus 49.11%, and burning and pain were more frequent.1

Does PDT help photoaging?

A review of 24 articles associated LED-activated PDT with smoother texture, fewer rhytides and improved scars, but noted that high-quality studies were scarce.2

Keep reading

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Related research

Sources

Where every claim comes from.

Numbers in brackets link to these entries. Journal entries were read as their PubMed record, and study details come from PubMed, the US National Library of Medicine. See every source on the Research Desk, organised by page.

  1. [1] Journal of Cosmetic Dermatology (Aldraibi and colleagues). Comparative efficacy of photodynamic therapy versus cryotherapy for actinic keratosis: a systematic review and meta-analysis of randomized controlled trials.
  2. [2] Dermatologic Surgery (Huang and colleagues). Light-emitting diode-based photodynamic therapy for photoaging, scars, and dyspigmentation: a systematic review.

This page is general information drawn from published reviews and studies. It is not medical advice and makes no light therapy claim about any Vanu Health product. The image is an AI-generated illustration, not a study image. Last updated October 30, 2026.