Everything you need to know about SPF

What is SPF?

SPF stands for sun protection factor, which is a measure of how well a sunscreen protects your skin from the sun’s rays. There are two main types of sunscreens: chemical and mineral.

Chemical SPF absorbs UV (ultraviolet) rays from the sun and converts them into heat. Mineral SPF reflects the rays away from your skin. Some sunscreens are a combination of both.

The number after SPF indicates how much protection the product will offer you. For example, SPF 30 offers 30 times the protection compared to wearing no SPF at all.

Why is SPF important?

SPF helps to protect your skin from DNA damage that can cause skin cancer and premature aging.

UVA rays cause skin aging, and UVB is the main cause of sunburn, as well as a major risk factor for skin cancer. Wearing SPF can greatly reduce your risk of melanoma, which is the most serious type of skin cancer, as well as more common skin cancers. One study showed there was around a 50 per cent lower risk of people getting skin cancer with daily SPF use.

Sunscreen FAQs

Below are some commonly asked questions about using SPF, as well as some tips for getting the most out of your product.

Will suncream stop me getting vitamin D?

No, sun protection such as SPF will not increase your risk of a vitamin D deficiency. Vitamin D levels can still rise even if you wear SPF every day. You can choose to have short periods of time with your arms and legs exposed to the sun before wearing SPF, but it's very important to avoid sunburn.

You can also get some vitamin D from your diet, and everyone in the UK should take vitamin D supplements from October to March. Some people, such as those with brown or black skin, are recommended to take a vitamin D supplement throughout the year.

How much SPF do I need to apply?

Most people don’t use enough suncream. It’s important to cover all exposed skin on your body and face thoroughly and generously. Remember to cover your neck and ears and reapply as needed.

How often should I reapply SPF?

SPF should be reapplied every 2 hours when you are outdoors. You will need to reapply more often if you have been sweating, swimming or rubbing your skin. This also applies to the SPF you put on your face too.

Does makeup with SPF in it count?

Most make up that contains SPF does not give you enough sun protection on its own. This is because you don’t apply enough of it to get the level of protection you need. Therefore, it should not replace SPF but can help to top up your levels instead.

What should I look for on the label?

There are several key things you should check before buying an SPF. They include the following.

• Does the SPF protect against both UVA and UVB rays? This is called a broad-spectrum SPF.
• Is the SPF factor 30 or higher? This offers higher protection than lower SPF factors.
• Is the SPF water resistant? This can help the product to last longer if you swim, but it should still be reapplied after being in the water.
• Is the SPF in date? Check the expiry date as out of date suncream is not as effective.

Using a broad-spectrum suncream regularly is one of the best things you can do for your skin health. If you have any concerns about new or changing moles or other skin issues, see a GP as soon as possible.