Paraben is the most used preservative in cosmetics, skincare, hair products etc. It's a popular choice due to its low cost, high efficiency as bactericidal and fungicidal in many different formulation. Basically it works in powder (eyeshadows, blushers), liquid (toner) and cream or gel (lotion, moisturizer). Paraben is considered to be much more superior compared to natural alternatives such as grape seed extract and vitamin E as natural alternatives tends to degrade easily thus reducing its effectiveness. Are there any other stuff as good as paraben as preservative? Yes, it formaldehyde yo! But everyone knows how dangerous formaldehyde is. Actually paraben is replacement of formaldehyde.
If you noticed, there are more and more companies, Like Everyday Mineral, ELF Mineral line etc coming up with products without paraben or its derivative/salt. 'Paraben-free' lately has becoming a selling point of certain beauty products. So what is wrong paraben?
Well, there have been a study conducted that detected presence of paraben in tissue sample of human breast cancer. Why link paraben and breast cancer? Some paraben had been shown to have the ability to partially mimic estrogen, a hormone that play involved in the development of breast cancer. The use of products such as deodorant, body spray and other products applied to the skin may contribute to presence of paraben in the tumour cells. According to the study, it may explains the reason why most breast cancer were found around the area that are close to the underarm.
This study done by Harvey and Everett (2004), however limited to 20 samples and it actually doesn't established direct link paraben to breast cancer. The way I see it, 20 samples is not statistically significant to represent the population of female. Think about it, wasn't contraceptive have way more estrogen that your shampoo did. Well, paraben in your shampoo only mimic estrogen partially.
Studies done by Soni et al., (2002 & 2005) shown that paraben is not carcinogenic (not causing cancer) and paraben eventho rapidly absorbed into skin, it is also rapidly metabolize and excreted in urine. However, some people might find that they are allergic to paraben 
At times, I think companies make use of this paraben controversies to sell their products. It is your personal choice as consumer to convert to paraben free product. Not all natural product are paraben free, so read the label. The easiest way to convert to paraben free cosmetics is by using mineral makeup. Why mineral makeup? Since mineral makeup in powder form, especially the loose powder form, it is very dry. Being very dry makes it unsuitable for bacterial growth. That's why most mineral makeup doesn't really have expire date. I have two jars of 5-years old mineral eyeshadow that is still good. One more thing, if you're buying paraben free product, make sure whatever preservatives they used to replaced paraben is safer than paraben *wink*
Lastly, I leave you with this video from my favourite dermatologist, Dr Schultz
- Harvey, P. W. and Everett D.J. 2004. Significance of the detection of esters of p-hydroxybenzoic acid (parabens) in human breast tumours. J Appl Toxicol. 2004 Jan-Feb;24(1):1-4.
- Soni, M.G., Carabin, I.G., and Burdock, G.A. (2005) Safety assessment of esters of p-hydroxybenzoic acid (parabens). Food Chem Toxicol. 2005 Jul;43(7):985-1015.
- Soni, M.G., Taylor, S.L., Greenberg, N.A. and Burdock, G.A. (2002) Evaluation of the health aspects of methyl paraben: a review of the published literature. Food Chem Toxicol 2002 Oct;40(10):1335-73.
- Nagel, J.E., Fuscaldo, J.T. and Fireman, P. (1977). Paraben Allergy. JAMA. 1977 Apr 11;237(15):1594-5.
disclaimer: This post is not to be taken as medical advice. I'm in no way a medical professional. Do your own research to know more about parabens as I believe there more updated studies than the one I presented in this post.