Reviews mixed on reformulated Mederma's effectiveness in improving scars

April 1, 2008

A new study of the recently reformulated, onion-extract-based gel Mederma finds it effective in improving the appearance of small surgical scars, while the results of a 2006 study aren't quite so positive in assessing the effectiveness of the gel when compared with a petrolatum-based ointment in improving the appearance of surgical scars.

Key Points

There appears to be some difference of opinion as to the effectiveness of Mederma, a topical gel, in healing surgical scars.

Mederma (Merz Pharmaceuticals) is a nonprescription gel that's been on the market for years.

"It's a long-standing treatment for improvement of scars," dermatologist Zoe Diana Draelos, M.D., says. "For quite some time, it's basically been the only treatment available in its class in the mass market for treatment of scars and wounds."

In recent months, Merz has reformulated Mederma by adding allantoin, a cell-proliferating healing agent that stimulates healthy tissue formation.

"Allantoin enhances healing and is on the Food and Drug Administration's skin-protectant monograph," says Dr. Draelos, who is also an independent researcher and was involved in clinical testing of the new formulation. Dr. Draelos says Merz funded the test, but she is not involved in any other way with the company.

Reformulated Mederma study

In the study, 60 subjects each had two benign growths removed. Dr. Draelos says the wounds that were created were not incisional, but superficial and mid-dermal. For each subject, one wound was treated with the Mederma gel; the other was untreated.

"We did not start treatment with the gel until after the wounds had healed - about two weeks," Dr. Draelos tells Dermatology Times. "We found the wounds treated with the gel showed decreased redness and improved appearance."

The results of a 2006 study, however, weren't quite so positive. The objective of this study, conducted by researchers at the dermatologic surgery unit of Harvard Medical School's Beth Israel Deaconess Medical Center, was to compare the efficacy between the Mederma onion extract gel and a petrolatum-based emollient, Aquaphor (Beiersdorf), in improving the appearance and symptoms of new surgical scars.

Aquaphor comparison study

Twenty-four patients were enrolled in the Harvard study. Each had a new surgical wound of at least 4 cm in length. Using a randomized, double-blinded, split-scar study design, each surgical scar was divided into two equal portions, with each half receiving treatment with either the onion-extract gel or the petrolatum ointment at the time of suture removal.

According to the study abstract, each product was applied three times daily for eight weeks, and each patient was evaluated at two, eight and 12 weeks following initiation of treatment. A follow-up phone interview was conducted at least 11 months after the subjects' surgery had been performed.

"Scar halves were evaluated by blinded investigators for overall cosmetic appearance, erythema and hypertrophy," write the study's authors. "We found no statistically significant difference between the two treatment groups in any of the outcome variables studied."

"The only controversy I see is, what's the best use for this wound-healing gel," Dr. Draelos says. "I'm not advocating the use of this gel - I'm just saying there are many kinds of wounds, and in our testing of the reformulated gel, it was shown to be effective."