How Do I Choose a Sunscreen?
Choosing a sunscreen ought to be simple. But in practice, the choice can be bewildering.
SPF30 or SPF50?
Mineral or chemical?
Tinted or invisible?
Water resistant?
Should it contain a moisturiser?
Should it contain antioxidants or one of the newer DNA-repair ingredients?
And does a sunscreen costing £80 really protect your skin better than one costing £8?
Fortunately, choosing a good sunscreen doesn't need to be complicated.
The most important considerations are the protection it provides, whether it suits your skin and, most importantly, whether you actually like it enough to use it regularly.
Sunlight contains different forms of ultraviolet (UV) radiation. The two that matter most to our skin are UVA and UVB.
Start With Broad-Spectrum Protection
UVB is the main cause of sunburn. Its intensity varies considerably according to season, time of day and geographical location.
UVA penetrates more deeply into the skin and plays an important role in premature skin ageing, pigmentation and the development of skin cancer. Unlike UVB, significant UVA can also pass through window glass.
This is why choosing a sunscreen simply by looking at the SPF number doesn't tell the whole story.
Look for a product offering good broad-spectrum protection against both UVA and UVB. In the UK, UVA protection may be indicated by a UVA symbol or a star rating.
If you'd like to understand more about what ultraviolet radiation actually does within the skin, read our article What Does UV Radiation Actually Do to Your Skin?
Should I Choose SPF30 or SPF50?
Patients sometimes point out that SPF30 provides almost as much protection as SPF50.
And technically, they are right.
When tested under laboratory conditions, SPF30 filters approximately 97% of UVB radiation, while SPF50 filters around 98%.
That doesn't sound like much of a difference. There is, however, an important catch.
Sunscreens are tested using a relatively generous quantity, approximately 2 mg of sunscreen per square centimetre of skin. Most people don't apply anything like that amount in everyday life.
Apply less sunscreen and you receive less protection than the SPF number on the bottle suggests. We know that inadequate application can substantially reduce the protection achieved.
For this reason, I always recommend SPF50
It gives us some margin for what happens in the real world, where sunscreen is rarely applied as generously or as consistently as it is during laboratory testing. Of course, SPF50 applied very sparingly is no substitute for applying sunscreen properly.
Should I Wear Sunscreen in Winter?
UV levels in the UK are considerably lower during winter than during summer, particularly for UVB.
Nevertheless, I generally recommend making sunscreen part of your year-round morning skincare routine. There is a practical reason for this as well as a scientific one.
Once we start deciding each morning whether sunscreen is necessary - It's winter. It's cloudy. I'm not going outside for long. It doesn't look very sunny today - a regular habit quickly becomes an occasional one.
And once the habit has gone, it becomes much easier to forget sunscreen on the days when protection really does matter. Applying it every morning removes that decision.
It becomes no different from brushing your teeth: simply something you routinely do.
This is particularly worthwhile if your aim is to reduce cumulative photoageing or pigmentation rather than simply to avoid sunburn.
What About Vitamin D?
Some people worry that regular sunscreen use could contribute to vitamin D deficiency.
Vitamin D is important, but deliberately exposing your skin to UV radiation isn't the only way to maintain adequate levels.
Vitamin D3 supplements contain cholecalciferol, This is exactly the same form of vitamin D3 that our skin produces naturally following UVB exposure.
Anyone concerned about their vitamin D level can discuss testing and supplementation with their doctor or pharmacist rather than regarding unprotected sun exposure as necessary for maintaining vitamin D.
Mineral or Chemical Sunscreen?
Both can provide very effective protection.
Mineral sunscreens principally use zinc oxide and titanium dioxide as UV filters. They can be a good choice for some people with sensitive or reactive skin, although certain formulations can leave a visible white cast.
Chemical sunscreens use organic UV filters. Modern formulations can be extremely effective and often allow manufacturers to produce lighter, more transparent products that many people find easier to wear every day.
There isn't one universally superior choice.
The better sunscreen is usually the one that provides appropriate broad-spectrum protection, suits your skin and that you are happy to use consistently.
Which Sunscreen Is Best for My Skin Type?
Just as with moisturisers and other skincare products, different formulations suit different skins.
If you have oily or acne-prone skin, you may prefer a lightweight, oil-free or non-comedogenic formulation.
If your skin is dry, a richer sunscreen containing moisturising ingredients may allow the product to double as your morning moisturiser.
For sensitive or reactive skin, simpler formulations may be preferable. Some people find mineral sunscreens easier to tolerate, although this isn't universally the case.
If you have rosacea, fragrance and other potentially irritating ingredients may be important considerations. Tinted formulations can also have the cosmetic advantage of reducing the appearance of redness.
For people prone to melasma or troublesome pigmentation, tinted sunscreens containing iron oxides can be particularly useful because they may provide additional protection against visible light as well as ultraviolet radiation.
Do Antioxidants and Other Added Ingredients Matter?
Sunscreens are increasingly being combined with other skincare ingredients.
These might include moisturisers, vitamin C and other antioxidants, peptides or newer ingredients intended to help protect against or repair some of the cellular damage associated with UV exposure.
There is good scientific rationale for combining photoprotection with antioxidants, and some of the newer DNA-repair ingredients are interesting.
But it is worth keeping their role in perspective.
Additional skincare ingredients may enhance a good sunscreen. They don't compensate for inadequate sun protection.
If you are interested in combining sunscreen with other evidence-based skincare, you may also find The Skincare Trinity - Vitamin C, SPF, and Retinoid useful.
Do I Need a Water-Resistant Sunscreen?
Not necessarily for normal everyday use.
But if you are swimming, exercising heavily or likely to sweat significantly, choosing a water-resistant product makes sense.
Remember that water resistant doesn't mean waterproof.
Sunscreen should be reapplied after swimming, heavy sweating or towelling, and during prolonged periods of significant sun exposure.
Does It Matter How the Sunscreen Looks and Feels?
Yes. Very much so.
We sometimes concentrate so much on SPF ratings and ingredients that we overlook something equally important: cosmetic acceptability.
Some sunscreens feel heavy or greasy. Some leave a white cast. Others are virtually invisible. Some are mattifying; others leave a dewy finish. Tinted products may look excellent on one skin tone and completely wrong on another.
You may also care about how the product sits beneath make-up or whether it irritates your eyes.
These aren't trivial considerations.
A theoretically excellent sunscreen that you dislike wearing and leave in the bathroom cupboard isn't a very effective sunscreen.
The product you enjoy using every morning is much more likely to protect your skin over the long term.
Does an Expensive Sunscreen Protect Me Better?
Not necessarily.
In the UK, perfectly good broad-spectrum sunscreens are available for relatively modest prices. At the other end of the market, sophisticated skincare sunscreens can cost £50, £80 or even more.
The difference in price doesn't necessarily represent an equivalent difference in sun protection.
More expensive products may contain additional skincare ingredients, more sophisticated formulations or particularly elegant textures. They may feel better on the skin, work better beneath make-up or offer tints and finishes that you prefer.
Those things can have value, particularly if they encourage you to use the product consistently.
But you don't need to spend a fortune to obtain effective sun protection.
Sunscreen Isn't the Whole Story
Finally, sunscreen shouldn't be regarded as an invisible shield that makes unlimited sun exposure safe.
During periods of strong sunlight, sensible photoprotection also includes seeking shade, wearing appropriate clothing and avoiding unnecessarily prolonged exposure to intense midday sun.
Sunscreen is one part, albeit an important one, of protecting our skin from cumulative UV damage.
If some of that damage has already occurred, you might also be interested in Can My Sun-Damaged Skin Be Improved?
So, How Do I Choose?
Look for good broad-spectrum UVA and UVB protection and, for everyday use, I generally favour SPF50.
Choose a formulation that suits your skin. Use a water-resistant product when circumstances require it. Don't assume that an expensive sunscreen necessarily provides better UV protection than a less expensive one.
And don't underestimate how important it is that you actually like the way product looks and feels on your face.
My preference is to make sunscreen part of the morning routine throughout the year, rather than trying to decide each day whether the weather warrants it.