By now you’ve probably heard about tech entrepreneur Bryan Johnson – the 47-year-old millionaire who’s on a mission to reverse his biological clock and become 18 again.

He’s spending $2 million a year on a program he calls Project Blueprint and so far, he’s had decent results. Apparently, 47-year-old Johnson has the heart of a 37-year-old, the skin of a 28-year-old, and the lung capacity of a teenager. Oh, and erm, the c0ck of a… much younger man.

Unfortunately, it seems Bryan Johnson has now hit a bit of a snag on his way to immortality/reverse-ageing: one of the 54 different supplements he’s been taking daily has been making him older, rather than younger. Whoops!

Johnson, who made over $300 million when his mobile and web payment company Braintree was acquired by PayPal in 2013, had been taking  a pill known as rapamycin, which is supposed to be used as an immunosuppressant to prevent organ transplant rejection, and as a treatment for certain cancers and rare diseases like tuberous sclerosis complex. It works by inhibiting the mTOR pathway, which plays a role in aging and age-related diseases, so in theory should have anti-ageing benefits.

Sadly for Johnson, rapamycin was having the opposite effect on him, for whatever reason. In fact it wasn’t only ageing him, but also giving him a load of unpleasant side effects, including skin infections, high glucose levels and an elevated resting heart rate. After five years of using the drug, he’s now decided to banish it from his daily supplemental intake.

Johnson wrote on X:

“Despite the immense potential from pre-clinical trials, my team and I came to the conclusion that the benefits of lifelong dosing of Rapamycin do not justify the hefty side-effects. With no other underlying causes identified, we suspected Rapamycin, and since dosage adjustments had no effect, we decided to discontinue it entirely.”

“Additionally, on October 27th, a new pre-print indicated that Rapamycin was one of a handful of supposed longevity interventions to cause an increase/acceleration of aging in humans across 16 epigenetic aging clocks.”

Johnson has been taking a lot of rapamycin in the five years he was using the drug. He called his routine the ‘most aggressive rapamycin protocol of anyone in the industry’, so I bet he feels pretty foolish about that now he realises it was having the opposite effect to what he intended. Fair play to him for being open and honest about it, though.

Now that his regimen is back on track, who knows? Bryan Johnson’s experimentation on himself could lead to a massive breakthrough for medicine and reverse-ageing, even if it is pretty mental that he’s spending $2m a year and putting himself through this exhausting routine to make it happen.

If he does end up living forever though, it will have been totally worth it. If not? Well, that’s a pretty big L on his record. Imagine if he dies in a freak car accident or something? That would suck.

Johnson also recently dumped his fiancée because her breast cancer was a ‘net negative’ on his future plans. What a guy.