Ask the expert: Everything you need to know about sunscreen
Interviewed by Gurminder for Doctify
I often see people in my clinic with skin problems that could have been avoided by regular sunscreen use. Here’s my guide to what you should know.
Why should I wear sunscreen?
There are two key reasons all skin types can benefit from using SPF. Firstly, ultraviolet radiation is estimated to be a causative factor in up to 86% of cases of melanoma, a potentially deadly skin cancer. Although skin type has a big effect on risk, there is still a risk of melanoma in pigmented skin. Secondly, ultraviolet radiation causes 90% of the changes associated with aging skin such as pigmentation spots, fine lines, and wrinkles. If anti-ageing is a concern, then SPF should be a vital part of your daily skincare routine.
Are all sunscreens the same?
There are two main types of sunscreen: chemical and physical (mineral). Chemical sunscreens contain ingredients that behave as filters and reduce the level of UV penetrating the skin. They take approximately 20 minutes before application to become effective and should therefore be applied before going outdoors. Physical or mineral sunscreens are products that typically contain titanium dioxide and zinc oxide which physically block ultraviolet radiation. They are often less user-friendly as they can be chalky, thick and do not easily wash off. However, people with extreme sensitivity to UV radiation may benefit more from these.
Should I really be wearing a sunscreen everyday?
Sunscreen should be applied daily if you are going to be outdoors or in the sun for more than 20 minutes. Even on a cloudy day, up to 80% of UV rays can penetrate the clouds. An SPF of 15 or above should be used. Those who burn easily should use no less than an SPF 30 daily. Sunscreen should be broad spectrum, offering protection against both UVA and UVB radiation. Sunscreens can irritate the delicate eye area, and specific products are available which offer protection in this site; good quality sunglasses are also a good idea. Do not forget to protect your lips with a lip balm that contains SPF.
How much sunscreen should I use?
An ounce of sunscreen should be enough to cover an adult from head to toe; this is roughly equivalent to a shot glass full. For face and neck application you should be using approximately one quarter of a teaspoon amount at each site.
How long does sunscreen last?
Sunscreen is generally designed to last three years. However, if it has been exposed to extremely high temperatures, looks like it has changed in its colour or consistency, or past it’s expiry date then it should be discarded.
How often should I reapply my sunscreen?
Sunscreen should be applied 30 minutes before going outdoors and reapplied every 2 hours to get the SPF value stated on the bottle.
Are expensive sun creams more effective than cheap ones?
The short answer is no; there is not, overall, a correlation between the price tag on a sun cream and its effectiveness. Some cheap sun creams are more effective than expensive ones – and vice versa – although both categories include good and bad products. The key thing to consider when choosing which product to buy is the level of protection it gives you against the sun’s damaging UV radiation; choose a product that is broad spectrum and offers protection against both UVA and UVB.