Vijay Yadav warned people not to start downing taurine — an amino acid abundant in plants, animals and some energy drinks — just because his mice and monkey study suggested it might be an elixir for long life. But that doesn’t mean they listened.

“The other day, I was talking to I think the scientific director of one of the largest pharma in the U.S., he was taking 14 grams of taurine per day,” said Yadav, or roughly 14 Red Bulls’ worth. “He asked me, ‘is it appropriate?’ I said, ‘I cannot recommend.’” 

New results published Thursday have vindicated Yadav’s caution — while casting doubt on his headline-grabbing 2023 results that made taurine a staple ingredient for biohackers wary of their ever-shrinking mortal coils. The data are a reminder of just how messy and complicated longevity studies can be, and how elusive treatments, or even just reliable markers, for aging remain.