Many people are familiar with common antibiotic side effects, such as nausea and diarrhea. But did you know that sun sensitivity is another potential issue associated with antibiotic use?

If you’re taking antibiotics, you probably have questions, including how long antibiotic sun sensitivity lasts, what type of SPF sunscreen you should wear, and more. Here’s a closer look at what you need to know:

A Brief Overview of Sun-Sensitive Drugs

Medications that cause reactions to the sun are called photosensitizers. On a structural level, the molecules in these medications can destabilize. If destabilization occurs, chemicals build up in the skin, resulting in increased sun sensitivity and other problems.

As detailed in a study published by the National Institutes of Health¹, drug-related sun sensitivity is divided into two types:

  • Photoallergy
  • Phototoxicity


Photoallergy is a reaction to medications applied to the skin’s surface. As UV light hits these topical medications, it changes their molecular structure. The result is the creation of small molecules called haptens², which trigger an immune response.

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Your white blood cells spring into action, but instead of helping, they can inadvertently create a variety of potential problems, mainly topically in nature. Common photoallergic issues include a rash similar to eczema, swelling, and general redness.

Unfortunately, just because UV rays cause photoallergy, it’s not limited to the locations that received sun exposure. It can spread across your body.


Phototoxicity is a reaction caused by oral, injected, and (less commonly) topical medications. It’s the most common type of sun sensitivity.

Damage is a three-stage process. First, the drug absorbs UV light. Next, that UV light releases into your skin. Finally, cell death occurs. 

Phototoxicity harms the top two layers of your skin, the dermis, and epidermis. You’ll likely notice redness, including blistering and peeling in severe cases. Additionally, your skin can feel hot, itchy, and otherwise uncomfortable.

What Antibiotics Cause Sun Sensitivity?

Antibiotics and sun exposure have a complex relationship. The FDA³ lists the following antibiotics as among the most likely to trigger sun sensitivity:

  • Ciprofloxacin
  • Doxycycline (Doxycycline sun sensitivity is especially common)
  • Levofloxacin
  • Ofloxacin
  • Tetracycline
  • Trimethoprim

Of course, many other medications can potentially cause sun sensitivity, so always read the labels carefully. 

Who Will Develop Sun Sensitivity to an Antibiotic?

Unfortunately, predicting sun sensitivity in individuals is often difficult, if not impossible. An antibiotic’s sun sensitivity can vary dramatically from person to person. One person can take a medication without a problem, while another might develop a severe reaction even after a single dose.

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However, the Mayo Clinic⁴ has identified a few common risk factors. If you want to know how long does antibiotic sun sensitivity last, consider the following:

  • Race – Lighter skin tones tend to react more severely to sun exposure
  • General products – Deodorants, disinfectants, fragrances, and other common products can create or amplify a sun allergy.
  • Skin conditions – Existing issues like dermatitis can increase your skin’s sensitivity to the sun
  • Heredity – If you have blood relatives with sun sensitivity, you’re more likely to develop it yourself.

If you’re susceptible to sun damage in general, you’re also more likely to experience sun sensitivity from antibiotics. Additionally, a person might have an inconsistent reaction to an antibiotic over time. The severity of the side effects can increase – or even diminish – as you continue to take it.

How to Minimize Sun Sensitive Reactions   

Protecting your skin from sun damage improves your health and appearance. Plus, it takes on special importance if you’re taking an antibiotic that potentially causes sensitivity to the sun.

Follow these tips to help protect your skin from sun damage:

Wear Sunscreen

Cover all exposed skin with sunscreen whenever you’re outside. The FDA⁵ recommends wearing sunscreen with a minimum SPF value of 30 or higher. Also, you want broad-spectrum sunscreen, which is the term for a sunscreen that protects against both Ultraviolet A and Ultraviolet B radiation.

Limit Time Spent Outdoors

You don’t have to stay inside for the entire time you’re taking antibiotics. However, try to avoid the sun when its rays are strongest. Use the Sun Index app to manage your sun exposure time.

Wear Clothing the Covers Your Skin

Along with sunscreen, you want to protect your skin with appropriate clothing. The American Academy of Dermatology⁶ recommends the following:

  • Long-sleeved shirts and pants – Dark colors and thicker materials provide the most protection
  • Sunglasses – Make sure they protect against UV rays
  • A hat – Wear a wide-brimmed hat to help protect your face, ears, and neck
  • Shoes – Avoid flip-flops and sandals

Additionally, dry clothes provide more UV protection than wet clothes. 

The Duration of Antibiotic-Induced Sun Sensitivity

So, how long does antibiotic sun sensitivity last?

The duration varies by individuals and medication. Generally, high doses of any antibiotic are more likely to result in stronger, longer-lasting reactions.

Most symptoms appear within a few hours after sun exposure. They can last about a week or more, with the effects sometimes outlasting the antibiotic cycle by several days or beyond. In severe cases, symptoms can last for many weeks or months, although that’s a rare situation.

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Final Thoughts

You want to contact your doctor at the first sign of sun sensitivity. They’ll provide guidance specific to your situation. You might need to switch antibiotics or simply take additional precautions to avoid the sun.

Typically, sun sensitivity is a temporary issue, although you’ll always want to watch out for even minor symptoms. Understanding what sun sensitivity is, and how to help protect against it, is vital to mitigating its effects.

* Toby Dash is a staff writer at where he blogs all about the world of skincare, health & beauty.

The Latest Tech To Avoid Sun Allergies
In order to avoid sun allergy, wear a broad-spectrum sunscreen, protective clothing, and know how much time to spend in the sun to protect yourself from dangerous UV radiation. It can be confusing to manage all these factors in your head but by using the latest technology like Sun Index, you can free your mind of worries. Sun Index, can take into account your skin type and clothing to give personalized daily sun-safety recommendations such as how much sunscreen to apply and when to reapply it.

  1. Kyuri Kim, Hyeonji Park, Kyung-Min Lim. (2015). Phototoxicity: Its Mechanism and Animal Alternative Test Methods. National Institutes of Health. Retrieved July 15, 2020.
  2. Dan A. Erkes, Senthamil R. Selvan, (2014). Hapten-Induced Contact Hypersensitivity, Autoimmune Reactions, and Tumor Regression: Plausibility of Mediating Antitumor Immunity. National Institutes of Health. Retrieved July 15, 2020.
  3. U.S. Food & Drug Administration. (2015). The Sun and Your Medicine. Retrieved July 15, 2020.
  4. Mayo Foundation for Medical Education and Research. (2018). Sun Allergy – Symptoms and causes. Retrieved July 15, 2020.
  5. U.S. Food & Drug Administration. (2019). Sunscreen: How to Help Protect Your Skin from the Sun. Retrieved July 15, 2020.