Mederma scar cream is very popular. Ask ten people about what they think is the best cream to treat scars and many of them will mention Mederma. But is this based on facts? Does Mederma really work?
In this review we will examine this product closely by looking at user experiences and by mapping what medical science has to say.
If you read reviews, for example on Amazon, you’ll find that opinions are mixed. Some users say they really notice improvement while others think they wasted their money and time. The problem with scar creams is that the effects not always can be attributed to the product used.
Many scars improve over time and keeping scars hydrated (with most any cream) will benefit them slightly. Another problem is a general lack of knowledge on this matter. It’s startling how many doctors and even dermatologists suggest their patients to use useless creams.
Mederma’s Active Ingredient
Mederma scar cream’s active ingredient is allium cepa or onion extract. There are a number of products on the market today that use extract of the common onion (Allium cepa) as an active ingredient. The German pharmaceutical firm Merz manufactures Mederma and Contracubex topical products, which are designed to improve scar appearance. Generic versions of Mederma are also sold under the name Cepalin.
It is thought that the active ingredient in the onion is a bioflavonoid with antihistamine and antiproliferative effects on both normal and malignant cells (“Mederma,” 2012). Other studies have revealed that onion extract is anti-inflammatory due to the presence of cepanes and anti-infective because of thio-sulfinates (Draelos, Zoe, D., MD, June 2008).
In order to thoroughly investigate whether or not this cream has some scientific evidence behind it we’ll have to look at studies on onion extract. And its effects on scar appearance.
Is onion extract effective for scar treatment?
Several studies published in the medical literature during the 1990s and 2000s discussed the efficacy of using onion extract to treat scars. The results of these studies were mixed.
One 1999 study published in the Journal of Dermatologic Surgery examined the effects of topical onion gel extract on 17 patients recovering from recent skin-cancer surgery. The study found no statistically significant difference between pre- and post-treatment evaluations of scar erythema and pruritus in the patients using the topical onion extract gel, and concluded that the topical onion gel was ineffective for improving scar appearance (Jackson, B. A., and Shelton, A. J., April, 1999).
A 2006 study was also published in the Journal of Dermatologic Surgery. This study evaluated onion extract gel versus petrolatum emollient for treatment of scars. The study included 24 patients with recent surgical wounds at least four centimeters in length. The study found no statistically-significant difference between those patients treated with the onion extract gel or those treated with ordinary petrolatum, and concluded that the onion extract gel did not improve scar cosmesis or symptomatology (Chung, V.Q., Kelley, L., Marra, D., and Jiang, S.B., February 2006).
A 2007 study was published in the Journal of Wound Care. This study evaluated the use of onion extract combined with silicone gel sheets on 60 patients. These patients were divided into three groups. Group 1 was treated with onion extract alone. Group 2 was treated with silicone gel sheets. Group 3 was treated with a combination of onion extract and silicone gel sheets together. The study found that the onion extract worked well to reduce scar color, while the silicone gel sheets worked well to reduce scar height. The most positive effects were noted in study Group 3, which used both the onion extract and silicone gel sheets together. The study concluded that onion extract can improve scars through multiple mechanisms, but it is ineffective at reducing scar height. The extract should be combined with silicone sheets to achieve the best results (Hosnuter, M., Payasli, C., Isikdemir, A., and Tekerekoglu, B., June, 2007).
A 2008 study was published in the Journal of Cosmetic Dermatology. This study evaluated the effectiveness of onion extract gel to improve the appearance of scars following excision. Sixty patients with symmetrical seborrheic keratoses at least eight millimeters in diameter in the chest area were studied after surgical removal of the skin growth. Some were treated with onion extract gel, and some were not; and patients were re-examined at four, six, and ten weeks, respectively. The study showed that for those who received the onion gel treatment, there was significant improvement in scar softness, redness, texture, and appearance (Draelos, Zoe, D., MD, June 2008).
A 2011 study was published in the International Wound Journal. Like the 2007 study by Hosnuter, Payasli, Isikdemir, and Tekerekoglu, from the Journal of Wound Care, this study evaluated the use of onion extract gel combined with silicone for scar treatment. Sixty patients after median sternotomy incisions were separated into two groups. One group was given twice daily treatments with a silicone derivative combined with onion extract gel, and one group was given a placebo. The treatment period lasted 12 weeks. It was found that using a silicone derivative plus onion extract gel is safe and effective for the preventing the hypertrophic scarring after median sternotomy (Jenwitheesuk, K., et al., December 14, 2011).
In conclusion, of the five studies reviewed above, three used onion extract by itself or in comparison to ordinary petrolatum. Of these studies, only the 2008 study by Draelos attested to the effectiveness of onion extract, while the other two stated it was not effective. Two of the five studies evaluated the effectiveness of onion extract combined with silicone, and these studies found the combination to be effective for treating scars.
I know from experience that most of scar creams don’t work since I have tried a lot of them. If you want to use a scar removal cream I would advice to use a silicone cream for these do have studies confirming their effectiveness. Examples of silicone gels are Zeraderm, ScarAway, InviCible, and Kelocote. InviCible is unique because it also has safe and proven effective scar lightening agents in it. Some of its ingredients are known to enhance the collagen formation in scar tissue. Click here to read an InviCible Scars review.
Chung, V.Q., Kelley, L., Marra, D., and Jiang, S.B. (February 2006). Onion extract gel versus petrolatum emollient on new surgical scars: prospective double-blinded study. Dermatol Surg, 32 (2), 193-197. Abstract retrieved from: http://www.ncbi.nlm.nih.gov/pubmed/16442038
Draelos, Zoe, D., MD. (June 2008). The ability of onion extract gel to improve the cosmetic appearance of postsurgical scars. J Cosmet Dermatol. 7, (2), 101-104. Retrieved from: http://lib-sh.lsuhsc.edu/portals/factts/handouts/5_Morgan_Erin.pdf
Hosnuter, M., Payasli, C., Isikdemir, A., and Tekerekoglu, B. (June, 2007). The effects of onion extract on hypertrophic and keloid scars. J Wound Care, 16 (6), 251-254. Abstract retrieved from: http://www.ncbi.nlm.nih.gov/pubmed/17722521
Jackson, B. A., and Shelton, A. J. (April, 1999). Pilot study evaluating topical onion extract as treatment for postsurgical scars. Dermatol Surg, 25 (4), 267-269. Abstract retrieved from: http://www.ncbi.nlm.nih.gov/pubmed/10417579