In 2015, Liz Parrish flew to Colombia and let someone inject an untested gene therapy into her body 150 times. She texted her kids that she loved them before it started. When it was over, she went for nachos.

Ten years later, her telomeres are longer than when she started, and she has taken 12 gene therapies in total.

Her decade of self-experimentation has produced peer-reviewed data, a growing protocol of gene therapies, and a company training its sights on making biological aging optional. Our conversation goes over what it took to become patient zero and what gene therapy for aging looks like in practice today, among other things.