Mederma Cream Ingredients

Mederma is a line of skin care and scar treatment products manufactured and distributed by Merz Pharmaceuticals. The line includes Mederma Cream Plus SPF 30 and five other products that claim to improve the appearance of visible scars and stretchmarks, including acne scars. The active ingredient in all the Mederma products is a proprietary herbal extract from a source that may surprise you.

Cepalin

Mederma Cream Plus SPF 30 contains Cepalin, a trademarked, proprietary extract made from allium cepa--the common garden onion. Onion juice from boiled onions is a traditional folk medicine remedy for acne, bruises, boils, bug bites and wounds, according to James A. Duke, author of "The Green Pharmacy Herbal Handbook."

Preservatives

All Mederma formulations also include three preservative ingredients--allantoin, methylparaben and sorbic acid. Allantoin comes from comfrey root and is an anti-irritant and anti-inflammatory in addition to its antimicrobial action. Methylparaben is one of a family of preservatives called parabens. Cosmetic manufacturers often use parabens because they are generally recognized as safe and unlikely to cause skin reactions. They generally use sorbic acid to prevent yeast from growing in their products.

Binding Agents

Most Mederma creams also contain xanthan gum, a thickening agent, and PEG-4, a polyethylene glycol used by cosmetics makers as a solvent and humectant. Humectants keep the cream or gel from drying out. All the Mederma products contain purified water as a solvent for the active ingredients.

Fragrance and Colors

All Mederma products contain an unnamed fragrance. One of them, Mederma for Kids, also includes two dyes, D&C violet 2 and FD&C red 4.

Mederma Stretch Marks Therapy

Mederma Stretch Marks Therapy cream also includes hyaluoronic acid, which is a hydrator that helps draw more moisture and the active ingredients deeper into your skin. It also contains extract of Centella asiatica, an aromatic herb that grows in Asia and Indonesia. Ayurvedic practitioners use Centella asiatica to promote skin and wound healing.