Can you replace your sunscreen with SPF containing moisturisers?

Moisturisers with SPF are becoming increasingly popular and SPF levels have now reached the same levels as traditional sunscreens, but do they really perform as well as each other? Our research says no!

UV Photography example
Using UV photgraphy to assess sunscreen application. Far left – normal camera, 2nd left – UV sensitive camera, 2nd right – UV camera after sunscreen application, Far right – UV camera after SPF moisturiser application

Using a specially modified camera that only sees UV light we assessed how efffectively people apply sunscreen and sun protection factor (SPF) containing moisturiser to their face. The results have revealed interesting findings.

We found that people generally do pretty well at applying sunscreen in terms of coverage but have a clear tendency to miss parts of their eyelid areas. However, they do worse when using moisturiser at the same SPF instead of sunscreen; achieving less overall protection and missing more of their face. Although the moisturisers definitely work to an extent, they are definitely better than nothing, our findings strongly indicate that you won’t be as protected when you use a SPF moisturiser so extra care should be taken to fully protect yourself.

Why did we carry out these studies?

Prolonged or excessive exposure to sunlight causes skin damage in the form of sunburn, premature ageing and increased risk of skin cancers. For these reasons there is a broad push to use SPF containing creams or sprays to protect ourselves from the worst of this damage. Traditionally these sunscreens have been specially designed formulations, however, more recently, daily moisturisers, makeups and a variety of other skin care products have started to include sun protective elements. These new products are great in terms of how they feel, smell, what they can do for our skin, and the idea that people will be more likely to use them and so protected more of the time. However, no one has really rigoursly investigated how effective the moisturisers really are. So we decided to ask; are SPF moisturisers good enough to use instead of sunscreens?

How did we perform our study?

Conor taking photoWe wanted to direcly compare the application habits of sunscreens and moisturisers so we bought two of the market leader products; SPF30 sunscreen and SPF30 moisturiser* and recruited 60 people to come visit us on two occassions. Each time they came, we shone a low intensity UV light** upon them  and took a picture with our special camera*** when they came in and then we asked them to apply either the sunscreen or moisturiser as they normally would and then took their picture again. We also asked the participants to fill out a quick questionnaire to try and find out some details that could help us interpret their behaviour.

UV photographs
Before and after UV pics from one of our participants (She did a really good job!)

As you can see from the pics, the SPF in the sunscreen/moisturiser absorbs the UV light and appears black on our pictures whereas the uncovered skin reflects the light back and appears lighter. Note that this imaging system also reveals non-visible sun damage and deep pigmentation in the skin – lots of freckles!

We developed an imaging processing program to automatically calculate what areas were covered and what weren’t for each picture. Our program was also able to map where those areas were on the face. We used this mapping feature to specificall  on as being particularly problematic. Importantly the eyelid regions are also a high risk area for paticularly nasty skin cancers.

What did we see?

UV images after sunscreen or spf moisturiser
Left = sunscreen, Right = moisturiser.  Lighter image on right indicates less UV absorption, less product applied. Note how the region around the eyes were missed – this was really common!
total intensity graph
Graph of how dark each picture was – each dot represents a single participant. Higher numbers = darker image

The results were pretty striking…

Side-by-side comparison of our participants’ images revealed the sunscreen images to be consistently darker than the moisturiser images. This means that less UV light absorption was happening with the moisturiser;  either because the moisturiser is less effective or, more likely, that the participants applied less to their faces.

Interestingly, our analysis also revealed that the participants also missed a larger area of their face when using the moisturiser. Specifically, participants missed 11% of their face on average with sunscreen whereas with moisturiser the area missed increased to 16%.

When we specifically considered the high-risk eyelid areas the with moisturiser application were even worse! Sunscreen users missed 14% compared with 21% with moisturiser.

face and eyelid missed graphs
Percentage missed graphs.  Left graph analysis of the entire face revealed that the moisturiser application was on average 5% worse than sunscreen. Right graph analysis of the eyelid regions showed that most participants performed much worse when applying moisturiser than sunscreen. Each dot is the values from one participant.

Another area that is particularly important is the part just between the eyes and bridge of the nose. This region, which we call the medial canthus, is an area where basal cell carcinomas form. These cancers burrow into the eye and often require removal of the eye. Our data showed that 80% of participants using both formulations failed to cover this region.

We also took a closer look at a few other aspects of the data. It turned out that males in our study performed better than females in terms of area missed. Also those participants with darker skin tone did slightly better than those with lighter skin.

What do these findings mean?

Before we started this study we expected that people would use less moisturiser as lathering on a thick layer doesn’t feel good so the first part of our data was no surprise really. Two products used for different things, yield different behaviour.

However, the differences in area covered were more surprising. Anyone who has ever had sunscreen in their eyes will tell you how much it stings, so we predicted and hoped that this would be less of a fear for our participants when using moisturiser leading to better coverage in this area.

We wanted to know if missing large areas of the eyelids is something that the participants were aware of. In our questionnaires we asked them to rate what they thought of their coverage and then showed them their pictures and asked again. The responses to these questions indicate that most people thought they had covered the eyelid regions much more effectively than they actually had.

Conclusions

Our data says that you probably shouldn’t rely on SPF moisturiser for your main sun protection needs. It’s not all doom and gloom, the moisturisers do work, they are better than nothing and using them regularly will help to protect you. However, if you are planning an extended period of time in the sun it’s much better to go with sunscreens.

The large area missed around the eyes mean that we should pay extra to that region when applying but, realistically, the (unconcious) fear of getting sunscreen/moisturiser in your eye means that we should really look to other mechanisms of protection; UV protective sunglasses whenever possible.

What next? Getting the message out there!

This was a relatively simple study but we think it has an important message. Please share the knowledge as widely as possible.

If you would like any more details please get in touch, one of the study authors would be happy to respond.

We have previously run public engagement events at local museums and hospitals (you can read our blog posts about these events here and here) and  also filmed with ITV and BBC for an earlier study we carried out into sunscreen application habits.

About the authors

Lizzy lourenco, performed these studies as part of a MRes in Clinical Sciences. She designed the questionnaires, performed the participant recruitment and acquired all the images, and analysed the data. Harry Pratt and Dr Yalin Zheng, are image analysis experts in the Institute of Ageing and Chronic Disease at the University of Liverpool. They wrote the code that converted the photographs into quantifiable data. Dr Gabriela Czanner is biostatistican also based at the University of Liverpool. She helped in study design and guided the statistical analyses. Dr Kevin Hamil and Mr Austin McCormick jointly conceived, designed and supervised this project. Kevin is a faculty member in the Department of Eye and Vision Science in the Institute of Ageing and Chronic Disease. Austin in a consultant ophthalmologist and oculplastics surgeon who regularly deals clinically with eyelid tumours.

Footnotes

This sort of research is easy to perform and could make a science project for schools, undergraduates etc. We’ve written a how to guide here. If you want advice on how to set anything up, you can contact us via the form aobve. Similarly, if you would like us to visit your school or other group setting you can contact us via the form.

* SPF30 moisturiser Olay Regenerist advanced anti-ageing. SPF30 sunscreen Soltan Sensitive hypoallergenic suncare lotion.  Note; we have no association with either of these companies or products and do not specifically endorse these or any other formulations! I include the details here for completeness.

**Our light sources were UV-A emitting LEDs. Note that UV-A does cause a small amount of skin damage, however, the most damaging aspect of sunlight is the shorter wavelength UV-B light. We didn’t want to damage our participants and so checked to see exactly what was given off – based on our readings, we calculate the exposure of our participants to be the UV-A equivalent of being outdoors in the UK on a sunny day for less than 1 min. Our light source is actually the sort of thing you might see in a nightclub! You can buy the lighting rigs we used from amazon KAM-UV bar – we used two in our set up, vertically mounted on photography tripods (image above).

***The camera we used was a conventional Canon DSLR (this is an amazon affiliate link but we actually used a relatively old second hand camera) equipped with a 60mm EF-S macro lens (we used f3.5, shutter speed 0.8s, you are working with quite low light from the LEDs!). The camera was modified to only see UV by lifepixel who replaced the internal hot mirror with a UV band pass filter. Conversion currently costs $475 dollars.

Conflicts of interest – None!

This research was performed by researchers in the Institute of Ageing and Chronic Disease at the University of Liverpool and NHS teaching hospital at Aintree Liverpool. None of the team have every received any products, money or other renumeration from any camera, lighting, sunscreen, moisturiser or other related companies. We do not endorse any products. We specifically want to stress that we performed this study as we thought it important than an independent group of researchers provided the evaluation.

Participants in the study were recruited from students and staff at the University of Liverpool. They received remuneration for taking part but were not informed of the purpose of the experiments nor shown the images until after the study was completed. Ethical approval was obtained from the University of Liverpool ethical review board.

Our equipment was purchased thanks, in part, to a Wellcome Trust Institutional Grant and through funds received directly from our research institution. The links above are provided for reference only. Please be aware that if you purchase products from amazon after arriving at their site via those links then we will receive a small percentage for referring you (usually 4%). Any money obtained through this mechanism will be used to buy supplies for our public outreach events such as photo paper and print cartridges.

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