Medications and supplements that react dangerously with sunlight

Taking advantage of hot, sunny days, whether sunbathing or spending time in nature, it's important to remember that some medications, supplements, herbs, and even cosmetics we use may react dangerously with UV rays. Which products can cause these reactions?

Reddened skin, itching, rashes, fluid-filled blisters, and pain are the most common symptoms of photoallergy. These symptoms do not appear immediately. They may activate only after 24 or even 48 hours following exposure to sunlight.

However, while spending time in the sun, we are at risk not only of photoallergies but also phototoxic reactions. We may notice their symptoms within a few minutes of exposure to UV rays. Both photoallergic and phototoxic reactions are related to photosensitivity, which can be triggered by some medications, herbs, or cosmetics.

Medications that react with UV rays include psychiatric, neurological, antifungal, and antidiabetic medications, medications used by patients with cardiovascular diseases, and nonsteroidal anti-inflammatory drugs such as ibuprofen, naproxen, and ketoprofen.

However, vigilance should also be maintained in herbal teas or supplements containing plant extracts such as angelica, celery, lovage, St. John's wort, or rue. In the case of cosmetics, products containing vitamin A, pyruvic acid above 60 millilitres per litre, glycolic acid, or salicylic acid above 2% can lead to undesirable reactions.

Interestingly, not everyone is at risk of a phototoxic reaction. Some people have particular genetic predispositions that make them more at risk.

- The longer we stay in the sun, the greater the risk that a susceptible person taking certain medications will experience a phototoxic reaction, which will be more severe. Factors at play here are the exposure dose and exposure time. Even though SPF creams are highly effective and recommended for everyone (regardless of whether they take medications or not), they are not a cure-all, and in the case of taking certain medications, one should avoid the sun regardless of the use of protective creams – explained Dr Bartosz Fiałek, rheumatologist, medical knowledge popularizer.