A middle-aged software entrepreneur in the United States is on track to spend US $2 million to reverse the ageing process to have the body of an 18-year-old, according to reports.

Bryan Johnson, 45, is on track to spend at least US $2 million on his body. He wants to have the brain, heart, lungs, liver, kidneys, tendons, teeth, skin, hair, bladder, penis and rectum of an 18-year-old.

Johnson is a millionaire who has more than 30 doctors and health experts monitoring his every bodily function, according to Bloomberg

The team, led by 29-year-old regenerative medicine physician, Oliver Zolman are more than a year into their experiments, which they collectively call Project Blueprint. This includes strict guidelines for Johnson’s diet (1,977 vegan calories a day), exercise (an hour a day, high-intensity three times a week) and sleep (at the same time every night, after two hours wearing glasses that block blue light).

“The body delivers a certain configuration at age 18,” Johnson said.

“This really is an impassioned approach to achieve age 18 everywhere,” he added.

In the interest of fine-tuning this programme, which required an investment of several million dollars, including the costs of a medical suite at Johnson’s home in Venice, California, he has to constantly monitor his vital signs.

Each month, he also endures dozens of medical procedures; some quite extreme and painful, then measures their results with additional blood tests, MRIs, ultrasounds and colonoscopies.

“I treat athletes and Hollywood celebrities, and no one is pushing the envelope as much as Bryan,” says Jeff Toll, an internist on the team.

All the work, the doctors say, has started to pay off. Johnson’s body is, as they measure it, getting medically younger.

“This is expected and fine,” he says of the criticism he’s received.