Drug & supplement interaction

Light Therapy + Alitretinoin

Alitretinoin brand name: Panretin.

Moderate Interaction
The bottom line Moderate

Light Therapy has a moderate interaction with Alitretinoin. Light therapy may increase the risk for photosensitization.

Read the full interaction report
SeverityModerate
LikelihoodPossible
EvidenceD
What do Severity, Likelihood & Evidence mean?
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Interaction report

Light Therapy and Alitretinoin

Here is the interaction we found between these two, with the evidence behind it.

Moderate

PHOTOSENSITIZING DRUGS

Why this applies to Alitretinoin

Alitretinoin falls under PHOTOSENSITIZING DRUGS — the group Light Therapy interacts with.

Light therapy may increase the risk for photosensitization.
Concomitant use of photosensitizing drugs with light therapy may increase the risk for phototoxicity and should be avoided.
Severity Moderate Likelihood Possible Evidence D

Interaction has been documented in animal or in lab research, or the interaction has been documented in humans but is limited to case reports or conflicting clinical research exists.

Dr. Brian Staiger, PharmD, BCPS
Dr. Brian Staiger explains PharmD, Clinical Pharmacist

Here's the thing to know about alitretinoin (Panretin): it's a retinoid gel you put right on Kaposi's sarcoma skin lesions, and retinoids like this can make your skin more sensitive to light. That means treated areas may sunburn or get irritated more easily than usual. When you add light therapy, which deliberately exposes you to bright light, the concern is that the two together could raise the chance of redness, burning, or extra skin irritation where the gel is applied.

To be clear, this is a theoretical caution based on how these things work, not something proven to happen often. Still, it's worth a quick chat with your doctor or pharmacist before combining them so you can use light safely and watch your skin.

References
  1. Pathirana, D., Ormerod, A. D., Saiag, P., Smith, C., Spuls, P. I., Nast, A., Barker, J., Bos, J. D., Burmester, G. R., Chimenti, S., Dubertret, L., Eberlein, B., Erdmann, R., Ferguson, J., Girolomoni, G., Gisondi, P., Giunta, A., Griffiths, C., Honigsmann
  2. Leon, A., Nguyen, A., Letsinger, J., and Koo, J. An attempt to formulate an evidence-based strategy in the management of moderate-to-severe psoriasis: a review of the efficacy and safety of biologics and prebiologic options. Expert Opin Pharmacother 2007; PubMed
  3. Morgan, M. and Khan, D. A. Therapeutic alternatives for chronic urticaria: an evidence-based review, Part 2. Ann Allergy Asthma Immunol 2008;100(6):517-526. PubMed
  4. Hoare, C., Li Wan, Po A., and Williams, H. Systematic review of treatments for atopic eczema. Health Technol Assess 2000;4(37):1-191. DOI
  5. Whitton, M. E., Pinart, M., Batchelor, J., Lushey, C., Leonardi-Bee, J., and Gonzalez, U. Interventions for vitiligo. Cochrane Database Syst Rev 2010;(1):CD003263. PubMed

What These Ratings Mean

Every interaction above is graded three ways — here’s the key to each label.

Severity how clinically significant the interaction is
Major

Clinically significant. Avoid the combination, or use only under close professional supervision.

Moderate

Usually worth avoiding or managing — may need monitoring, a dose change, or timing apart.

Minor

Generally not serious. Be aware of it and mention it to your pharmacist.

Likelihood how strong the evidence is that the interaction actually happens in people
  • LikelyWell-controlled human studies have demonstrated the likely existence of this interaction.
  • ProbableInteraction has not been documented in well-controlled studies, however, the interaction has been demonstrated in some small human studies or in controlled animal studies in conjunction with multiple case reports.
  • PossibleInteraction has been documented in animal or in lab research, or the interaction has been documented in humans but is limited to case reports or conflicting clinical research exists.
  • UnlikelyInteraction has been demonstrated in animal or in lab research but has been shown not to occur in humans.
Evidence the quality of the studies behind the rating (graded A–D)
  • AHigh-quality meta-analysis (quantitative systematic review).
  • BCase-control study.
  • CConsensus.
  • DAnecdotal evidence.

These ratings are for information only. Never start, stop, or otherwise change your therapy before speaking with your provider.

Keep it in perspective

Light Therapy Also Interacts With Other Medications

Light Therapy has 334 moderate known drug interactions in our database — the Alitretinoin one above is one of them. If you take anything else, check it against the full list below.

Taking anything else?

Check Another of Your Medications Against Light Therapy

Covers the 2,830 medications we’ve checked against Light Therapy. Pick one to open its full report.

Everything else you take

See Every Supplement That Interacts With Alitretinoin

This page covers Light Therapy only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Alitretinoin page lists 38 supplements it has a documented interaction with, worst first, each one explained.

The most serious there right now: Activated Charcoal (major), Vitamin A (major), Alfalfa (moderate), Angelica Archangelica (moderate) and Arrach (moderate).

By severity: 2 major · 26 moderate · 10 minor.

From our pharmacist’s overview on the Alitretinoin page

“Alitretinoin (Panretin) is a retinoid gel used on Kaposi sarcoma skin lesions, and because it is a vitamin A derivative, treat these 38 supplement interactions with genuine care. Two carry a major rating.”

Reviewed by 2 · Jul 18, 2026

Open the Alitretinoin interaction page

How much people look this up

Where Light Therapy and Alitretinoin Sit Against Everything Else

Out of every supplement and medication people look up on HelloPharmacist, here is where these two land this week — and which way each has been moving.

Supplement Light Therapy
Top half

#611 of 1,452 supplements looked up here in the last 7 days

29 days ago today
Medication Alitretinoin
Top half

#1,107 of 2,830 medications looked up here in the last 7 days

29 days ago today

Position among everything looked up on this site, not a measure of how commonly either one is used or how important it is. A supplement can climb this list because of a news story. It counts every request to the page, automated ones included, and nothing here identifies anyone.

Treatment approach

About Light Therapy

What is Light Therapy?

  • Seasonal affective disorder (SAD)
  • Non-seasonal depression
  • Sleep and circadian rhythm problems
  • Jet lag and shift-work sleep issues
  • Certain skin conditions

Light therapy uses controlled exposure to bright artificial light and is best supported for seasonal affective disorder, where it is a recognized treatment option. It is generally safe for most people when used as directed, but you should talk to a doctor or pharmacist first, especially if you have eye conditions, bipolar disorder, or take medicines that increase light sensitivity.

Read the full Light Therapy monograph & all interactions
Medication

About Alitretinoin

What Is Alitretinoin Used For?

Brand name: Panretin

Panretin Gel is approved to treat cutaneous lesions — visible skin sores — in adults who have AIDS-related Kaposi's sarcoma (KS), a cancer that causes abnormal tissue to grow in the skin.

Panretin Gel is applied directly to the affected skin spots. It is not for use when the disease has spread widely enough to need systemic (whole-body) treatment — for example, when there are more than 10 new lesions in a month, or when the lungs, lymph nodes, or internal organs are involved.

See full Alitretinoin drug information
Keep checking

Other Drugs & Light Therapy

Browse every other medication we’ve checked against Light Therapy — both the ones with a known interaction and the ones without. Select any drug for the full detail.

0Major
334Moderate
0Minor
2,495No known interaction
Moderate

334 interactions

Showing 60 of 334 moderate interactions — see all 334 on the Light Therapy page.

No interaction 2,495 drugs checked — show the list
Sources

Sources & How We Checked

Interaction details are evidence-graded and sourced from the Natural Medicines database. The medication overview comes from MedlinePlus.

Content is written and reviewed by licensed HelloPharmacist pharmacists. See our data sources and editorial standards for how this information is built and checked.

Parts of this content are provided by the Therapeutic Research Center, LLC.

DISCLAIMER: Currently this does not check for drug-drug interactions. This is not an all-inclusive comprehensive list of potential interactions and is for informational purposes only. Not all interactions are known or well-reported in the scientific literature, and new interactions are continually being reported. Input is needed from a qualified healthcare provider including a pharmacist before starting any therapy. Application of clinical judgment is necessary.

© 2021 Therapeutic Research Center, LLC

Keep exploring
Pharmacist Counseling Corner

Having Light Therapy While Taking Alitretinoin: Common Questions

Can you have Light Therapy while taking Alitretinoin?
There is a moderate interaction, so it may be acceptable with monitoring or timing changes — but check with your pharmacist first. Read the full details on this page and confirm with your pharmacist before combining them.
How serious is the Light Therapy and Alitretinoin interaction?
We rate it Moderate. This combination may require monitoring, a dose adjustment, or separating the times you take each one. Consult your pharmacist before using them together.

Written and reviewed by the HelloPharmacist editorial staff. Our editorial policy

Still Have a Question About Alitretinoin and Light Therapy?

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This information is for education only and is not a substitute for professional medical advice. Always check with your pharmacist or doctor before starting, stopping, or combining supplements and medications.