Aesthetic Dermatology

Onion Extract Improved Scars by 36%



RALEIGH, N.C. – A new once-daily topical gel containing a proprietary onion extract resulted in a 36% improvement in the appearance of recent postsurgical dermal scars at 8 weeks, according to the results of a randomized, controlled trial.

The over-the-counter product, Merz Pharmaceuticals’ Mederma Advanced Scar Gel, was studied in 44 adults, each of whom underwent surgical shave removal of two similar-size seborrheic keratoses on the chest. At 2 weeks, after the wounds had reepithelialized, patients were randomly assigned to apply the nonprescription onion extract gel once daily to one scar and no treatment to the other.

Dr. Zoe D. Draelos

Blinded investigator assessment was carried out after 2, 4, and 8 weeks of once-daily therapy. Each scar was graded on a 0-3 scale for improvement over baseline for overall appearance and for more specific individual domains of texture, redness, and softness. Patients independently carried out the same assessments, explained Dr. Zoe D. Draelos, a clinical dermatologist and researcher in High Point, N.C.

At week 8, investigators rated the onion extract–treated scars as demonstrating a mean 2.6-point improvement over baseline in terms of overall appearance, with comparable improvements noted in texture, redness, and scar softness. These were significantly better outcomes than was the mean 2.1-point improvement in the overall appearance of untreated control scars, she noted.

The patients rated the onion extract gel–treated scars as showing a mean 2.0-point improvement at week 8, significantly better than the 1.5-point improvement noted in the control scars.

Although optimal results were seen at week 8, the topical gel–treated scars showed a significant advantage in appearance scores, compared with control scars, as early as week 4, with a nonsignificant favorable trend noted at week 2.

The chief advantage that the transparent onion extract gel offers over other scar treatment products is the convenience of once-daily application, noted Dr. Draelos.

Merz announced the launch of Mederma Advanced Scar Gel in the spring. It is available in the first-aid section of pharmacies nationwide at a retail price of about $20 for a 20-g tube and $32 for 50 g, according to the company.

Other Merz products containing Cepalin, the proprietary onion extract, include Mederma Scar Cream plus SPF 30, Mederma for Kids, and Mederma Stretch Marks Therapy.

Dr. Draelos received research funding from Merz to conduct the clinical trial.