Nuffield Health has raised £18.6 million for its Nuffield Health Bond, surpassing its initial target of £15m.
Funds raised will be invested in the charity's healthcare services across the country that focus on prevention, fitness and wellbeing.
The Nuffield Health Bond is a five-year fixed term product which offered a fixed annual return of 6% (gross) in cash for investments of between £1,000 to £250,000.
More than 1,300 individuals invested in the bond, with the average investment amount being £14,000 per person.
KP Doyle, group chief financial officer for Nuffield Health, said: "We are delighted with the support shown from stakeholders in our bond. Going significantly beyond our £15m target shows the trust our customers and staff have in the Nuffield Health brand.
"Nuffield's balance sheet is one of the strongest in our sector and given the demonstrable demand for the Health Bond, we will to continue to explore innovative sources of funding to promote our vision of 21st century healthcare."