Normally, drug makers must seek the agency’s permission to test new drugs, a process that often takes years and costs hundreds of millions of dollars. But now a growing number of cases of DIY gene therapy are putting the health regulator in a difficult situation as individuals argue that no law stops them from self-administering the substances. In fact, there is a long history of scientists carrying out experiments on themselves, including some Nobel Prize winners.

Last month, Josiah Zayner, CEO of The Odin, which sells DIY biology kits and supplies through its website, posted a video in which he injected himself with the gene-editing tool CRISPR during a biohacker conference in California. That video has been viewed more than 58,000 times on YouTube.

In its statement, which FDA Commissioner Scott Gottlieb tweeted on November 21, the same day it was posted to the agency’s website, the regulator took aim directly at companies selling CRISPR supplies intended for self-administration.

“I think that’s totally in response to the experiment I did on myself,” says Zayner, a self-described biohacker who promotes the idea that anyone should be able to participate in scientific experimentation.

Unknown risks

Experts say any gene therapy prepared by amateurs would probably not be potent enough to have much effect, but it could create risks such as an immune reaction to the foreign DNA. “I think warning people about this is the right thing,” says David Gortler, a drug safety expert with the consulting group Former FDA. “The bottom line is, this hasn’t been tested.”

The problem facing regulators is that interest in biohacking is spreading, and it’s increasingly easy for anyone to obtain DNA over the internet. It’s also easy to get hold of the recipes necessary to carry out gene editing using CRISPR, a potent new technique for modifying DNA.

In October, Zayner’s website began selling $20 copies of a DNA molecule containing the necessary genetic information to deactivate the human gene for a certain protein, myostatin, using CRISPR.

Animals without that gene develop extra-large muscles, so it is frequently cited by biohackers as a target for self-improvement experiments.

Zayner says selling the supplies isn’t illegal because it’s not up to him how people use them. His website warns that the product is “not injectable or meant for direct human use.” Human DNA can be purchased through a number of other companies that cater to research labs. The difference is The Odin markets its DNA to amateur biologists.

“The DNA we sell is kind of to inspire people, and maybe people will buy the DNA and use it. I don’t really have a problem with that,” says Zayner. He said he won’t stop selling any of his products in light of the FDA’s statement last week.