Bryan Johnson, a prominent life extension advocate, has revealed that he has been diagnosed with Autoimmune Gastritis (AIG), a serious, incurable autoimmune disease. He discovered this condition in May and mentioned the health issues it causes, including B12 and iron deficiency. Johnson attributed his AIG to poor dietary choices in his youth and the stress of parenthood. Despite the challenges posed by his disease, he plans to pursue experimental approaches for a cure and is open to collaborations with others researching AIG. Johnson, who actively tracks and documents his health journey, perceives his diagnosis as validation of his health-focused lifestyle. He has a history of controversial health practices, including taking numerous supplements and even blood transfusions from his son, and believes technological advancements in medicine could provide solutions for his condition.

‘Don’t Die’ Guy Bryan Johnson Says He Has Serious Autoimmune Disease

"My stomach is eating itself," wrote Johnson.

By Matt Novak Published July 6, 2026, 6:23 pm ET

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Bryan Johnson speaks at a conference in Beverly Hills

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Bryan Johnson, the life extension guru who chronicles his efforts to reduce his “biological age,” says he has Autoimmune Gastritis (AIG), an incurable disease that he only discovered he had in May. Johnson wrote on X that he doesn’t know how long he’s actually had AIG, which causes B12 and iron deficiency, leading to anemia. But he’s vowing to work on “experimental approaches” to find a cure and has asked anyone working on the disease to reach out.

Johnson, who’s 48 years old and constantly chronicling his efforts to maximize his health online, blamed his AIG on unhealthy foods he ate in his youth, along with the stress that came with being a father.

“As a kid, I ate sugar cereal, drank sugary soda, and gobbled down fast food. I had a few healthy years in my early 20s but then became a young father of three and began building a business,” wrote Johnson.

“Juggling that stress and grind, I let my health slip and gained 40 lbs. Within a few years I’d fallen into a deep, chronic depression. Somewhere in that timeline, my body began developing an autoimmune process affecting my thyroid and then my stomach lining,” Johnson continued.

Bad news #1:

I have an autoimmune disease. My stomach is eating itself.

Bad news #2:

2–5% of people have this, too. Likely more, because it hides.

Good news:

I'm going to try and solve it. Will share all.

As a kid, I ate sugar cereal, drank sugary soda, and gobbled down… pic.twitter.com/EbJ8a916uS

— Bryan Johnson (@bryan_johnson) June 30, 2026

Johnson takes dozens of pills per day and was featured in a 2024 Netflix documentary called Don’t Die: The Man Who Wants to Live Forever. He founded the company Braintree, which bought the payments app Venmo in 2012. Johnson then sold Braintree to PayPal for $800 million.

Johnson owns a company called Blueprint that sells a number of products he says can make you live longer, including everything from dietary supplements to extra virgin olive oil. He’s spent millions in an effort to live forever and his obsession is often criticized as no way to live a life of fulfillment and joy. But the tech founder rejects those criticisms and seems to believe that his new diagnosis has completely validated his worldview.

“It’s worth noting that many of you give me a hard time, inviting me to ‘live life’ and engage in self-destructive behaviors like a ‘normal person’. I’m cool with the playful ribbing. Also, had I not taken care of my health during the past five years, my situation could potentially be very serious,” wrote Johnson.

The playful ribbing takes many forms online, but some of the most ridiculed tweets Johnson has posted involve things like tracking his 19-year-old son’s erections in order to compare them to his own. He also chose to tweet about his son’s erections in a rather odd manner, writing “raise children to stand tall, be firm, and be upright.”

Nighttime erection data from my 19-year-old son, @talmagejohnson_, and me. His duration is two minutes longer than mine.

Raise children to stand tall, be firm, and be upright. pic.twitter.com/ruIYyPMrUC

— Bryan Johnson (@bryan_johnson) January 22, 2025

Johnson has also spent millions on blood transfusions from his son, something that has connections to bad illnesses like graft-versus-host disease, according to the NIH. He’s also tracking the amount of microplastics in his semen, the kind of analysis that most normal people would not necessarily become fixated on.

But this is no normal man. Johnson is determined to age in reverse, and will do just about anything to make that happen, even if it’s not technically possible. He’s also an optimist in many ways, as you can see in his tweet about the diagnosis. He firmly believes that anything is possible if you throw enough technology at a problem. Even conquering death.

“In the age of AI, multiomics, and custom-built DNA, proteins, and cells, no condition should be presumed incurable simply because no one has yet tried to cure it with today’s stack,” wrote Johnson.

Johnson’s company Blueprint didn’t immediately respond to questions emailed Monday. Gizmodo will update this article if we hear back.

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