Protect and perfect and not at all convinced

Boots the chemist are making much of research just published in the British Journal of Dermatology. It involves their Protect and Perfect product, which is on sale in my local store, where there are signs saying that customers are allowed to buy only 6 bottles. Clearly they are anticipating great demand.

In 2007, the BBC program Horizon revealed results of a test of Protect and Perfect. They used it on 15 people over 12 days, applying the cream to the forearm and then assaying skin samples for fibrillin, which – say Boots may ”perhaps clinically improve photoaged skin”. 

Rightly, this experiment was criticised, and it was announced that proper trials were going to be done, and here, in the BJD, they are.

This is what Boots says about it:

“The trial was an independent study of 60 volunteers over an initial period of six months. Half the volunteers used No7 Protect & Perfect Intense Beauty Serum and the other half used a placebo product (the same formula, but without the anti-ageing ingredients). Neither group knew which product they had been given.

The results for No7 Protect & Perfect Intense Beauty Serum were astounding. After the initial six months were over, skin on the volunteers using the real No7 Protect & Perfect Intense Beauty Serum showed some repair of the damage caused by sun exposure. No changes were seen for the group using the placebo product.

Use of the No7 Protect & Perfect Intense Beauty Serum for an additional six months led to clinical reduction in the appearance of wrinkles, assessed by an independent dermatologist. Seventy per cent of people perceived a marked improvement in their skin, thus proving that the skin looks better the longer you use No7 Protect & Perfect Intense.”

I don’t think that’s quite how I’d put it. Certainly, it was an RCT, and that’s good. The 60 participants were blinded to either the placebo cream or the test cream for six months. After six months the groups were unblinded and they all used the test cream. However the study used linear regression analysis to “extrapolate the vehicle response to 12 months, thus allowing comparisons with the test product”. This seems like a bad idea to me: this technique is not as true to life as doing the comparative test in real life would be.  The assessments of skin changes were made by two dermatologists, and I am not convinced that we know this is a reliable and reproducible tool. But very interestingly, in the abstract summary it says “at six months, the test product produced statistically significant improvement in facial wrinkles as compared to baseline assessment (p=0.013) whereas vehicle-treated skin was not significantly improved (p=0.11).” A p value of less than 0.05 is usually treated as being statistically significant in medical papers. However, in the discussion section, please note (and my caps):

“Compared to the baseline, the test product did lead to a noticeable clinical improvement in facial wrinkles (P=0.013) in 43 per cent of treated individuals after six months, compared with only 22 per cent of those treated with the vehicle where there was no significant improvement in appearance (p=0.11). In a comparison between groups THIS IMPROVEMENT WAS NOT STATISTICALLY SIGNIFICANT but does indicate that larger clinical trials of cosmetic products might be expected to show useful clinical improvement after six months’ use.”

I interpret that as bit of a wish-list. I’m not astounded either.

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