What is it? Used to treat Alzheimer's disease, depression and stroke, idebenone only recently entered the skin care market with a big, exciting bang; dermatologists and patients alike anticipated its arrival. Idebenol, a similar ingredient, has also enjoyed surging popularity. And it isn't merely hype: there's research to suggest both idebenone and idebenol are effective anti-aging ingredients.

For one, idebenol and idebenone guard skin against free radical damage, says dermatologist Audrey Kunin, M.D. It's free radicals, or environmental factors, including chemicals, pollutants and cigarette smoke, that damage skin and cause signs of aging, such as wrinkles, dryness and age spots.

Idebenol. UV rays also produce free radicals, harming cell proteins and lipids, causing cell damage and death, Dr. Daniel B. Mowrey tells SkinStore. One study found that idebenol protects cells from UV damage and death, whereas untreated cells had a much higher death rate, adds Dr. Mowrey.

Research also suggests idebenol boosts skin renewal, a process where skin cells go through stages of growing, flaking away and being replaced by new cells, clarifies Dr. Mowrey. In younger people, the renewal rate is faster than older people.

Dr. Mowrey cites a study where renewal rates were measured for a mature group — averaging 67 years old — and a young group — averaging 29 years old. The mature group applied idebenol, whereas the young group received no treatment. The mature group's average renewal rate dropped from 24.1 days — their rate before treatment — to 18.6 days. The young group's renewal rate was 16.6 days on average. So, this study suggests that idebenol speeds up cell renewal, producing smooth, new skin to replace rough, older skin.

Business Wire also reports encouraging anti-aging results:

• After one month's use, there was a 30 percent reduction of visible lines and wrinkles; after three months, the figure jumped to 57 percent.
• A 33 percent decrease in the "appearance of wrinkle depth after one month." With three months' use, there was a 55 percent reduction.

Idebenone. Described as a "high-octane antioxidant" by Linda Dyett in an article for Prevention magazine, idebenone is viewed as a super-antioxidant. A variant of Coenzyme Q10, idebenone might actually be more powerful than its chemical cousin.

For instance, Coenzyme Q10 is open to oxidization, which actually creates harmful free radicals. Idebenone doesn't do this, giving it an advantage. Smart SkinCare's Dr. Todorov — biologist and cell researcher — also notes that idebenone might fight off free radicals better than Coenzyme Q10. However, he adds that studies directly comparing Coenzyme Q10 and idebenone as skin treatments are needed.

According to Dr. Kunin, specific tests that measure an antioxidant's efficiency have suggested idebenone's superiority over other antioxidants, including Coenzyme Q10, vitamin E and C and kinetin. Here's a closer look at what the tests determine:

• How much sun exposure is needed to cause a burn — the Minimal Erythema Dose (MED); antioxidants that offer protection raise the MED.
• How many cells are sunburned after sun exposure; antioxidants that offer protection lower this number.
• How many thymine dimmers from UV damage are produced by cells; antioxidants with good protection lower this number.

However, Dr. Kunin cautions that we must also consider the concentration or percent of other antioxidants in a product. One antioxidant may require 0.5 percent concentration to be effective; another may require 20 percent.

Dr. Andrew Scheman — dermatology professor at Chicago's Northwestern University — suggests in The (London) Independent that idebenone is better absorbed by skin than other antioxidants.

You'll find it in: Currently, both idebenol and idebenone are included separately in various anti-aging creams. You might want to talk with your dermatologist about the best formula for your skin's needs.

Our product picks: Try Prevage Anti-Aging Treatment By Elizabeth Arden and Allergan with 0.5 percent idebenone. Use Prevage Anti-Aging Night Cream By Elizabeth Arden and Allergan at bedtime to moisturize, add firmness and promote even tone. To encourage skin renewal and reveal fresh, healthy skin, try Sovage Idebenol.

What to expect: With both idebenone and idebenol, you might notice an overall improvement in skin and a reduction in fine lines and wrinkles. According to the Prevention article mentioned above, one tester — who used Prevage, which contains idebenone — remarked, "My skin looked as if it had been airbrushed." The article also emphasizes idebenone's ability as a powerful antioxidant to reduce collagen breakdown and potentially inflammation.

With idebenol, according to Dr. Mowrey, "Consumers can expect to observe improvements in the appearance of lines and wrinkles, in the smoothness of the skin, in the absence of dryness, roughness and flakiness, in the hydration or water content of the skin, in improved barrier functionality and in resistance to UV damage."

Who should avoid it: Dr. Kunin notes that Prevage hasn't been studied for use during pregnancy. Despite low chance of absorption by the bloodstream, ask your doctor before use.

Allergan — the maker of Prevage — warns that reactions and irritation can occur in patients with sensitive skin or certain conditions. The company advises patients to test Prevage on a small area for a few days. Stop use if you have redness, burning or swelling. If you tolerate Prevage well, you can gradually increase use to twice daily after two weeks. Check with your dermatologist about other products with idebenone and idebenol to learn which ones are best for your skin.

See also:

MD Formulations Product Review

Top 3 Skin Concerns for Athletes

Steamy Secrets: At-Home Facial Steaming

How to Find a Great Dermatologist

Is Your Diet Aggravating Your Skin?