A 1999 pilot trial found an onion extract gel less effective than the petrolatum. A 2002 study published in
Plastic and Reconstructive Surgery examined the effectiveness of Mederma on hypertrophic scars on rabbit ears. It found no significant reduction in the size, height, or inflammation of scars. The only improvement was dermal
collagen organization when compared to scars that were not treated with Mederma, thus suggesting that it may have a positive effect on the formation of raised scars. A 2006
clinical trial found no
statistically significant change in
hypertrophic scar appearance from products of this type compared to the standard petrolatum emollient. According to a 2011
Los Angeles Times article, "there were just two randomized comparison trials of Mederma, with a combined total of 38 participants. Neither trial found that Mederma improved the appearance of scars more than
petroleum jelly". ==Ingredients==