Bryan Johnson spends about $2 million a year trying not to die. On Wednesday, in a single tweet, the man best known for trying to reverse his own aging said he wonders if he's taken it too far. He earned the money to try. Johnson sold his payment company Braintree, the business behind Venmo, to eBay for $800 million in 2013. Most of that fortune has gone into Project Blueprint: a team of more than 30 doctors, over 100 supplements a day, and constant testing of nearly every system in his body. He claims the protocol has him aging at 0.69 years for every calendar year that passes, with 50 biomarkers (blood, hormone, and organ measurements doctors use to judge how well a body is working) rated at the top of the scale for his age. The most famous part of his routine didn't work. Johnson injected himself with a liter of his son's blood plasma six separate times, chasing a rumored anti-aging effect. He found no real benefit and stopped. What continues is smaller and less viral: Johnson still donates his own plasma to his father. Not every experiment ended quietly. Years earlier, he tried injecting donor fat into his face, an attempt he called Project Baby Face. It left him swollen and temporarily unable to see. He posted the photos anyway, part of a habit of sharing his failures along with his wins. Seven months before Wednesday's tweet, Johnson raised the stakes instead of lowering them. In February, he launched Immortals, selling his exact protocol to three paying clients for $1 million a year each. He also claimed AI and biotechnology could make immortality "a reasonable target" by 2039. The U.S. National Institute on Aging says researchers still lack a reliable way to confirm that changing a biomarker extends a life. Johnson didn't say he was quitting. He said he'd been thinking. Nine years, $2 million a year, and one tweet of doubt later, the protocol is still running.