Zayner has a background in biophysics and runs a company called The Odin, which sells do-it-yourself genetic engineering kits and other lab equipment intended for use outside of scientific laboratories. He also has a long history of experimentation on himself, including an attempt to genetically engineer his skin.
However, one of his most well-known experiments was an October 2017 livestream when he injected himself in the arm with what he said was DNA for the genetic engineering tool CRISPR. The stated goal was for the CRISPR-Cas9 gene-editing machinery to snip and disable Zayner's myostatin gene, which is involved with muscle-growth regulation before and after birth, in order to experience beefy muscle growth. Zayner admitted—and outside experts agreed—that the experiment was unlikely to work, however, it brought the attention of the Food and Drug Administration, who called genetic-editing kits illegal.
READ MORE: Scientists Use CRISPR Tech to Create World’s First Genetically-Modified Lizard
According to a May 8, 2019 letter Zayner posted to his Instagram account on Wednesday, health investigators at the Department of Consumer Affairs are following up on a complaint alleging Zayner is practising medicine without a license. The investigators are "now at the point in our review where we would like to discuss this matter with you," the letter reads.
Zayner denied that he has ever “given anyone anything to inject or use, never sold any material meant to treat a disease, and never claimed to provide treatments or cures”, noting that people are dying not because of the DIY-genetic kits but because the “FDA and government refuses to allow people access to cutting-edge treatments or in some cases even basic healthcare.”
In a later follow-up on twitter, Zayner said that he would probably need to find a lawyer. Practising medicine without a valid license in California can be tried as either a misdemeanour or a felony, with penalties up to a $10,000 fine and three years in prison.