Millionaire Bryan Johnson is making his anti-aging 'basics' available for $333 a month to 2,500 people

• 46-year-old tech entrepreneur Bryan Johnson is known for his anti-aging program.
• He's offering the basics of his program to 2,500 participants for around $333 a month.
• More ambitious participants can also invest up to $1600 into measuring biomarkers.

Bryan Johnson — the 46-year-old tech entrepreneur who founded the payments processing company Braintree — may be best known these days for his rigorous anti-aging program.