ProActive, Hamsters and Science

Photo: courtesy of Maarten Dirkse under the CC license. 

Now, I don't actually care about Chinese hamsters, although I am a very caring person and I love animals.


However, and sadly, Chinese hamsters were used to test the topic effects of benzoyl peroxide, and guess what? They were bad. 

"Benzoyl peroxide, a widely used free radical-generating compound, promoted both papillomas and carcinomas when it was topically applied to mice after 7,12-dimethylbenz[a]anthracene initiation. Benzoyl peroxide was inactive on the skin as a complete carcinogen or as a tumor initiator. A single topical application of benzoyl peroxide produced a marked epidermal hyperplasia and induced a large number of dark basal keratinocytes, effects similar to those produced by the potent tumor promoter 12-O-tetradecanoyl phorbol-13-acetate. Benzoyl peroxide, like other known tumor promoters, also inhibited metabolic cooperation (intercellular communication) in Chinese hamster cells. In view of these results caution should be recommended in the use of this and other free radical-generating compounds."

Source:  ScienceMag.org

Guess in which product you can find benzoyl peroxide. 





Huh, you're right: ProActive. 

Here is the full list of ingredients: 
Renewing Cleanser
Active Ingredient: benzoyl peroxide 2.5%.
Inactive Ingredients: water (aqua), magnesium aluminum silicate, glyceryl stearate, PEG-100 stearate, disodium dimethicone copolyol sulfosuccinate, sorbitol, dimethyl isosorbide, polyethylene, tridecyl stearate, neopentyl glycol dicaprylate/dicaprate, tridecyl trimellitate, cetyl esters, anthemis nobilis flower extract, sodium hyaluronate, sodium PCA, propylene glycol, xanthan gum, imidazolidinyl urea, methylparaben, propylparaben, fragrance (parfum).


Repairing Lotion
Active Ingredient: benzoyl peroxide 2.5%.
Inactive Ingredients: water (aqua), cyclomethicone, ethoxydiglycol, propylene glycol, glyceryl stearate, PEG-100 stearate, cetearyl alcohol, dimethicone, panthenol, allantoin, carbomer, ceteareth-20, xanthan gum, triethanolamine, diazolidinyl urea, methylparaben, propylparaben, fragrance (parfum).




I don't know whether they have a disclaimer on their products, but I wouldn't use that stuff.