Featured photo by Anna Demianenko on Unsplash

We love busting a skin myth, you know we do. It is our coffee replacement in the morning, what keeps us cranking out exclusive Nerd Network content just for you.

In this post, we’re talking about this particular skin myth: you shouldn’t use exfoliating acids in the Summer months. This skin myth is based on the fact that many exfoliating acids photosensitise the skin, making it more likely to experience the effects of UV damage.  

What is photosensitisation?

Photosensitisation is the term used to explain how the skin can become more sensitive to light, including UV rays. Acids aren’t the only thing that cause photosensitisation. Culprits include antibiotics such as doxycycline, tetracycline and levofloxacin, certain antidepressants, certain anti-inflammatories (including ibuprofen), retinoids and more.

The effects of photosensitisation will be worse for those with conditions that can be triggered by the sun. Those with inflammatory skin conditions, such as rosacea, eczema and psoriasis, will see this, as will those who are prone to cold sores.

We never want to paint the sun as the villain. UV rays are a bit like that friend who you adore spending time with but need to be wary of as they could turn on you at any moment (look, we all have them, and if you don’t, maybe it is you). If you protect yourself to the best of your ability, you’re golden!  

Exfoliating acids and photosensitisation

Exfoliating acids, including the majority of AHAs (alpha hydroxy acids) and BHA (beta hydroxy acid, salicylic acid), can photosensitise the skin as they work to increase skin cell turnover. In this process, the trade off includes losing some of the skin’s own UV-protective capability. This is why it’s particularly important to wear SPF everyday if you’re using active, acid-packed skincare!

Interestingly, one type of exfoliating acid helps to counteract the light sensitivity by actually protecting the skin from some of the damaging effects of UV radiation. Can you guess what it is? It’s the wonderful polyhydroxy acid, or PHA, which we cannot stop raving about. Gluconolactone, one particular PHA, has been proven in studies to provide up to 50% protection against UV radiation, and does not encourage a significant increase in sunburn cells when it is used. In the interest of transparency, the amount of gluconolactone needed to have these capabilities won’t always be found in skincare that contains gluconolactone. It’s just nice to know of its potential benefits!  

Why you can use exfoliating acids in the Summer months

Because of the photo-sensitising effects, some decide to advise against using acids and other chemical exfoliants in the Summer months. It makes sense on one level: reduce the sun-sensitiser, reduce the chances of sun-sensitisation.

But at The Skin Nerd, we have faith in you as hoomans that you know to be sun-savvy and protect your skin properly. You are smart cookies. You wear your SPF daily, apply the right amount, and you try to avoid long amounts of sun where possible. We never want you to be sun-fearful, that’s not our bag. We do provide you with information on how to protect your skin from the sun, though, and for the good of your skin health, we’d feel faaaairly strongly that you’d put it into practice.

A recap of the nerdie guide to sun-savviness, although you undoubtedly remember it from your Nerd or Nerdette:

• Apply at least a half-teaspoon of SPF for your face, neck and ears
• For your whole body, you should be using at least 6 teaspoons of SPF (a little more than a half a teaspoon per arm, more than one teaspoon per leg, more than one teaspoon for your chest and torso, and more than one teaspoon for your back - don’t forget any of the bum you may expose)
• Reapply when in direct sunlight after 2 hours, and after getting wet, sweating a lot or having your SPF rubbed off
• Get every single millimetre of exposed skin - using a mirror is key
• Wear a big hat and shades as even more protection
• Don’t spend prolonged amounts of time in direct sunlight (unfortunately, this does include sun-bathing)

If you’re worried about heightened chances of sunburn, or know you will be in the sun for prolonged amounts of time, you could consider dropping the acids from your routine for a little while or at least cutting down. The choice is yours!

Clearing up confusion: the non-exfoliating acids

Now, in skincare, some ingredients are acids but not exfoliating acids. These acids don’t photosensitise the skin. Case in point: hyaluronic acid. Hyaluronic acid doesn’t prompt the skin’s own exfoliation process, as exfoliating acids do - it’s just a humectant hydrator that pulls moisture into the skin.

Lactic acid is an exfoliating alpha hydroxy acid that is also a humectant hydrator, and in some products, it’s added in smaller amounts for its humectant capabilities. In these formulations, such as in the IMAGE Ormedic Balancing Antioxidant Serum (€70.50), it’s not acting as a potent exfoliant so it won’t cause the same sun sensitivity.

Citric acid is another AHA you’ll find in skincare that can exfoliate in higher amounts but it is most often found in miniscule amounts to balance the pH of a product.

Too long, didn’t read:

Wear your SPF and be sun-savvy, and you’ve very little to be worried about.

Stock up on your favourite SPF right here, or get Skingredients Skin Shield SPF50 PA+++ (€42.00), our first own-brand SPF, from stockists nationwide!