Sun protection
SPF30 or SPF50+: which do I need, and how much should I apply?
The NHS recommends a sunscreen with at least SPF30 and at least 4-star UVA protection. SPF50+ filters slightly more UVB in laboratory testing, but in everyday use, applying enough and reapplying matter more than the jump from 30 to 50.
What is the difference between SPF30 and SPF50?
SPF measures protection against UVB, the main cause of sunburn. Under laboratory conditions SPF30 lets through roughly one thirtieth of UVB and SPF50 roughly one fiftieth, so the difference in UVB filtered is a few percentage points rather than a doubling of protection.
UVA is measured separately. In the UK look for a star rating, ideally 4 or 5 stars, or the letters UVA in a circle, which indicates the product meets the EU standard.
Why does the amount matter so much?
SPF is tested using a generous, even layer. Most people apply much less, which means they get considerably less protection than the label suggests. As a guide, the NHS suggests adults aim for around 6 to 8 teaspoons of sunscreen to cover the entire body.
For the face and neck, use enough to cover every area evenly, including ears and hairline, rather than a thin smear. If a texture makes you skimp, a different format is usually a better answer than a higher number.
How often should I reapply?
The NHS advises reapplying every 2 hours, and straight after being in water, even if the product is water resistant, as well as after towel drying, sweating or anything that may rub it off. Check the expiry date, and follow the directions on your product.
Is sunscreen enough on its own?
No. Use shade, especially between 11am and 3pm in the UK summer, and clothing, hats and sunglasses. Babies under 6 months should be kept out of direct strong sunlight. Sunscreen reduces exposure; it does not make extended sun exposure safe.
A few more questions
On Serenova
- Ultrasun Face SPF50+
A daily facial SPF50+ we currently stock.
- Ultrasun Photo Age Control Fluid SPF30
A lighter SPF30 fluid option.
- How to choose a sunscreen
Texture, mineral or chemical filters, and pigmentation.
- Ultrasun at Serenova
The full available Ultrasun edit.
Further reading
Your next step
Start with a routine your skin tolerates. Product guidance is not a diagnosis; after a procedure, your treating clinician's instructions always come first.