Elizabeth Parrish, CEO of the biotech company BioViva, claims that her body's cells are 20 years younger after testing her company’s age-reversing gene therapy on herself.

The 45-year-old Seattle-area woman, who has no scientific or medical training, underwent the experimental treatment last September in an undisclosed clinic in Colombia. The unorthodox, overseas trial, which was designed to skirt US federal regulations, prompted the resignation of one of the company’s scientific advisors. George Martin, of the University of Washington, quit after telling MIT Technology Review, "This is a big problem. I am very upset by what is happening. I would urge lots of preclinical studies.”

Though details of the fast-tracked trial are unpublished, Parrish says it involved intravenous infusions of an engineered virus. That infectious germ carried the genetic blueprints for an enzyme called telomerase, which is found in humans. When spread to the body’s cells, the enzyme generally extends the length of DNA caps on the ends of chromosomes, which naturally wear down with cellular aging. In a 2012 mouse study, Spanish researchers found that similar treatment could extend the lifespan of the rodents by as much as 20 percent.

Parrish claims that test results from March—which have not been published in a peer-reviewed scientific journal—reveal that her blood cells’ telomeres have extended from 6.71 kilobases of DNA to 7.33 kilobases. The difference, she estimates, equates to a cellular age difference of 20 years.

However, scientists are skeptical of the results and the claims for several reasons.

First, while scientists have found correlations between health and telomere length, it’s not clear if shortened telomeres actually cause health problems or if they’re just a side effect of aging.

But perhaps more importantly, telomere length doesn’t have a clear connection to health—for instance, cardiovascular diseases are linked to shorter telomeres, but cancer is associated with longer lengths. “[T]he idea that in the general population relatively short telomeres are bad and relatively long telomeres are good is nonsense,” Abraham Aviv, a telomere researcher at Rutgers, wrote in an e-mail to The Scientist.

Last, the difference in telomere length that Parrish and her company report—about a nine-percent increase—is within the standard error of most telomere length measurements.

Still, Parrish is convinced that the therapy will work to reverse aging. She is now searching for regulatory partners in different countries that will allow her to perform more trials. “When I started looking into this, it seemed like a crazy science,” Parrish told The Scientist. “But it’s a crazy science whose time has come.”