How does sunscreen work?

When it comes to choosing a sunscreen, there are two types, physical (Mineral) and chemical. In some sunscreens the substances create a chemical filter that blocks most of the sun’s rays by absorbing the radiation.  In other sunscreens, a physical filter acts as a barrier on top of the skin, reflecting away the rays that hit your skin. Hybrid sunscreens contain a combination of both chemical and physical filters and offer the best protection to prevent skin cancer.

Whats the difference in UV-A and UV-B?

The sun’s rays are invisible and are known as ultraviolet(UV) rays. There are both UVA and UVB rays and both types of rays can be dangerous in excessive amounts. The sunscreen needs to be broad spectrum which means it protects against UVA and UVB. The UV index indicates the intensity of harmful UV radiation. When the UV index rises above 3, it is important to use sunscreen.

How long does a sunscreen last?

A sunscreen typically lasts for 12 months after you open it. However, the shelf life will be shorter if you store the sunscreen at higher temperatures. If your sunscreen smells funny or has changed colour or consistency, you should throw it away and buy a new one to make sure it actually works.

What about a moisturiser with SPF?

The highest SPF that can actually be incorporated into a moisturiser is SPF 25. These products are often more cosmetically acceptable on the skin than a thicker sunscreen. The best sunscreen for any person is the one they actually wear;  so a moisturiser with an SPF will also work well.

What factor sunscreen should I wear?

The reason most Doctors recommend factor 50 sunscreen daily is because if you use a very good quality factor 50 sunscreen, it will last a lot longer than factor 15. If you are absolutely diligent about reapplying sunscreen during the day then factor 15 is satisfactory, however, most people don’t reapply sunscreens frequently enough.

It also depends on where you are living. The UV index in countries near the equator is much stronger and more dangerous than in countries like Ireland or the UK. The level of activity also matters. If you are very sporty and sweat a lot or are swimming then the sunscreen needs to be re-applied.

SPF 15 blocks 93% of the sun’s UV rays. SPF 30 blocks 96% of the rays and SPF 50 blocks 98% of UV radiation. If you work outdoors you will need a higher sun protection factor.

Who actually needs to wear a sunscreen?

Babies’ and children’s skin needs to be protected. The number of sunburns a patient experiences as a child affects their possibility of getting skin cancer later on in life.  I would always recommend a high protection for children.  A good adult sunscreen would work very well for children.  Children’s sunscreens are the same but they will have less ingredients in them that can irritate the skin.

Older patients or men with no or thinning hair should wear sunscreen every day on exposed areas ( face, neck back of the hands scalp and ears). These patients are at much higher risk of skin cancer.  These patients should use high-quality hybrid sunscreens SPF 50 every day.

Teenagers with acne spots or post-inflammatory hyperpigmentation post acne should wear daily sunscreen to prevent acne scarring.  These patients should consider more physical-based sunscreen as a chemical sunscreen can be oily and block pores which will worsen acne vulgaris.

All people who want to keep good healthy-looking skin should incorporate a sunscreen into their daily routine, Once a patient is over 30 years of age their natural ability to protect their skin starts diminishing and the signs of ageing,  pigmentation, wrinkles, broken veins and redness. 

What sunscreens do you recommend as a Doctor?

There are lots of good sunscreens on the market. The best one is the one you wear every day. For older patients with drier skin and obvious signs of ageing or pre-cancerous lesions, I would always recommend the REFORM Skincare SPF 50+.  This is a combination of physical and chemical products and so has very high protection and should be used by all patients who are at high risk for skin cancer or have a lot of sun damage, photo-ageing or dyspigmentation. It should be used every day on all exposed areas.

The REFORM Skincare SPF 30 is a mineral-only sunscreen. It is for patients with oily or acne-prone skin or very sensitive skin because it will not irritate the skin or block the pores. These sunscreens are harder to rub into the skin so should be used over a topical vitamin C serum or moisturiser. This sunscreen is suitable for patients with acne vulgaris, acne rosacea, or very sensitive skin.