Hairlines have receded faster than usual during the pandemic due to both stress and the aftereffects of COVID 19. After a coronavirus infection, many people experience increased hair shedding starting two to three months after becoming sick, and continuing for a total of six to nine months.

A Silicon Valley biotech startup, dNovo, has developed a possible solution for this problem. The company claims it has managed to reprogram ordinary cells, like fat or blood cells, into human hair follicles.

Starting with a few drops of blood, dNovo can produce customized hair stem cells that can be used to create new hair. The cells are said to be able to evade any immune system response that would reject them.

DNovo, founded by Stanford University–trained biologist Ernesto Lujan, had its first breakthrough in 2019 with a patent-pending technology that regenerates various kinds of human cells into hair stem cells. The process requires five steps: collecting cells, reprogramming them, growing the new hair-producing cells, adding those hair-producing cells to human scalps, and finally waiting one to three months for the hair to grow.

The technology is years away from being ready for humans. For now, its effectiveness has been shown to work only on mice.

“We are currently in the preclinical stage of development,” Lujan told Fortune. “We have shown the results in laboratory mice and are very excited with those.”

He added, “We hope to eventually demonstrate the efficacy in human trials and make our product commercially available, but at the moment we are in the early stages of the whole process.”

DNovo is not the only company working on lab-grown hair cells. Another biotech company, Stemson Therapeutics, received $15 million in funding in July to find a cure for hair loss with “with a novel cell regeneration technology using the patient’s own cells to generate new hair follicles.”

In 2006, Japanese researcher Dr. Shinya Yamanaka discovered a formula to convert any type of human tissue into stem cells. Since the discovery of so-called iPSCs, they have become the basis for many cutting-edge therapies.

Stemson Therapeutics is among them. The company claims that it is the first to “leverage an iPSC approach to treat hair loss by generating de novo hair follicles.” Its technology is not yet commercially available.

People who want more hair have long been able to get hair transplants. However, the number of such transplant procedures is declining as U.S. consumers switch to ingestible products and foams including Nutrafol and Rogaine.