Mineral sunscreen explained: what it is and how it works

Research shows that UV exposure is responsible for up to 80% of the visible signs of ageing,¹ which is why a high-quality sunblock that protects against both UVA and UVB rays is essential.

It may seem slightly confusing, but mineral sunscreens contain inorganic UV filters, while chemical sunscreens contain organic UV filters. The most common filters in mineral sunblocks are zinc oxide and titanium oxide. Chemical sunblocks are usually formulated with a mixture of three to five filters such as avobenzone, oxybenzone and cinnamates.²

Mineral sunscreens are sometimes called ‘physical’ blockers because they sit on the surface of the skin and help block UV radiation. “They primarily absorb UV light, while also reflecting and scattering a small amount,³ whereas chemical sunscreens mainly absorb UV and convert it into heat,” Dr Laftah says.⁴

These are the key differences between mineral and chemical sunscreens:

It works very quickly by forming a barrier against UV rays, whereas chemical sunscreen needs around 15 minutes to absorb into the skin and take effect.⁶ However, to be on the safe side all sunscreens should be applied about 15 minutes before sun exposure. According to recent research, tinted mineral sunscreens containing iron oxide have an extra benefit, too. By blocking blue light, they may help to reduce dark spots caused by hyperpigmentation.⁷

Here are three commonly held but incorrect beliefs about mineral based sunblock:

“Traditionally, mineral sunscreens were viewed less favorably because they tended to leave a white cast, especially on those with darker skin types,” Dr Laftah says – but that’s no longer the case. Nowadays, many are formulated using nanotechnology, meaning the mineral particles are extremely small and spread more easily, making them look more transparent on the skin. “They come in gel as well as cream formulations and are often tinted to reduce some of that white cast even further. That was a limiting factor in the past but it’s not as much of an issue anymore.”

Whatever type of sunscreen you use, it’s very important to apply enough product to ensure adequate protection – around six to eight teaspoons to cover your body.⁸ For adults, Dr Laftah recommends at least half a teaspoon of sunscreen for your face, neck and ears, and at least six to eight teaspoons to cover the whole body.

Some mineral sunscreens wash off more easily, so if, for example, you’re very active or go swimming a lot on holiday, you may prefer to use a chemical sunblock or cover up with UPF (Ultraviolet Protection Factor) clothing, which is clothing designed to help protect your skin from UV and UVA rays.⁹

There are pros and cons to both mineral and chemical sunscreens but the best option is one that you feel comfortable using.

Disclaimer – This article provides informational advice and is not a substitute for medical care. Working with experts for accuracy, we take great care to ensure the information is up-to-date and relevant. However, you should always consult your GP or healthcare professional before using supplements or alternative products, particularly if you have medical conditions or are under supervision.