Carried out by the University of Liverpool, the small-scale study recruited 14 men and 46 women aged 18 to 57 and asked them to apply sun protection to their face to see how effectively people apply products.
During one visit participants were asked to apply an SPF30 sunscreen, and on the second visit a moisturizer with SPF30.
The researchers then took photos of the participants' faces with a specially modified camera that only sees UV light to assess how effectively people had applied the two products. When an area of the skin has been sufficiently covered, the product absorbs the UV light and this area then appears black in the photos. The lighter the area in the photo, then the less successful the absorption.
The researchers found that when applying moisturizer, the participants missed 16 percent of their face on average, however they were more effective at applying sunscreen, with this figure dropping to 11 percent.
The team also looked at just the eyelid areas, as it is a high-risk area and a common site for skin cancers, finding that here participants missed 14 percent of the area when using sunscreen compared with 21 percent with moisturizer.
In addition to missing parts of the skin, the researchers also found that participants did not apply the moisturizer as thickly as sunscreen, reducing the effectiveness of the SPF in the moisturizer.
However, some people were better than others at applying the products, with the team finding, that on average, men were significantly better at applying them than women, as were people with darker skin tones, and older participants.
Mr Austin McCormick, one of the study's researchers, commented on the findings saying, "We expected the moisturizer to perform worse than the sunscreen on overall protection, as it seemed intuitive that people apply moisturizer quite thinly on the whole."
"Although moisturizer with SPF does provide sun protection, our research suggests that it's not on the same level as sunscreen. We would not recommend it as a like-for-like replacement for your sun protection needs."
Matthew Gass of the British Association of Dermatologists added, "Another important thing to take away from this research is that people often miss areas of their face when applying sun protection, a good way to prevent this from becoming an issue is to wear sunglasses and reapply sunscreen regularly. This should help protection the bits you miss from being exposed to excessive sun."
The results are to be presented at the British Association of Dermatologists' Annual Meeting taking place July 3 to 5 2018 in Edinburgh. More information about the study can also be found online.