Photosensitizers: Enemies of sunlight

Contrary to popular belief it's not in August, the hottest month of the year, that the sun's rays are most harmful. It is rather towards the end of June, around the time of the summer solstice, that the sun hits the boiling point… so to speak.

There is a wide array of products we don't think about that can cause redness or spots when we're out in the sun. Do you take birth control pills? Dermatologists recommend taking the pill at night instead of in the morning, in order to keep hormone levels at their lowest during sun exposure.

But your greatest foes in the sun are photosensitizers, products that increase sensitivity to solar rays and reduce your exposure time. They often cause sunburns and, in some cases, redness and itching. There are many photosensitizers. For example, though it may be pleasant to enjoy a cold lemonade on a hot day, lemon - and especially lime - can be harmful. See our feature on foods that promote tanning. Prefer an iced tea instead? Certain artificial sweeteners can cause dark spots on the skin.

Pregnant Women
Pregnant women should also use strong sunscreens, with an SPF between 30 and 60, and combined with UVA/UVB protection. Without the proper protection, pregnant women often get dark pigmentations on their cheeks and forehead - a condition known as pregnancy mask.

The sun can be a friend rather than a foe - you just need to tame it!



Many cosmetics, perfumes and colognes should be avoided if you're going to be exposed to sunlight. You should never apply perfume or eau de toilette before exposure to the sun. You may end up with brown spots or small burns. These substances contain photosensitizers such as musk ambrette, sandalwood oil and bergamot oil, used in high-end perfumes, as well as rosemary and lavender oil. As for men, some colognes and aftershaves contain lime.


Similarly, certain types of medication can cause intolerance to sunlight and local reactions if you take them before going out in the bright sun. People taking certain prescription drugs (sulfonamides, tetracycline and thiazide diuretics) or herbs (St. John's wort, for example) have increased susceptibility to adverse effects from sun exposure. There are numerous other regularly-used medications that make the skin extremely sensitive to the sun. Medications most commonly associated with photosensitivity are:

  • retinoic acid
  • numerous antibiotics
  • antihistamines
  • tranquilizers
  • antidepressants
  • arthritis medications and over-the-counter pain relievers
  • barbiturates
  • quininolone antibacterials
  • anti-arrhythmics
Everyday products

Everyday products
Don't use deodorant before exposure to the sun. Many hotels in sunny destinations no longer offer deodorant soaps but provide mild soaps on the bathroom vanity instead. 

If you use medicated cosmetics ask your cosmetician if you can use the product before sun exposure. Many products contain sunscreen rather than photosensitizers so all you have to do is choose carefully!

You should also avoid washing your hair. Some shampoos and conditioners contain photosensitizers. If you've ever found yourself scratching your head while tanning, now you know why!

Our point, however, is not to spoil your fun! Certain skin types are actually less sensitive than others and you shouldn't panic while reading the list of sunbathing foes. Study the way your skin reacts after being exposed to the sun. If you see spots or signs of irritation, redness or an uneven tan, then modify your product use accordingly.


Related Articles
Search within the site
Register free to receive our official newsletter
Sign up