Brown made his debut for Harlequins in summer 2005 and spent another 16 years with the club before moving to Newcastle and then Leicester, initially on a short-term deal midway through the 2022-23 season.
His performances have earned a couple of contract extensions and he scored five tries in 20 appearances last season.
Brown says that his longevity is partly thanks to a commitment to conditioning and rehabilitation throughout his career.
He has long employed famed sprint coach Margot Wells, who helped husband Allan Wells win 100m Olympic gold at Moscow 1980, to put on additional sessions during his free time.
“Finding someone you train with regularly and who knows your body inside out, I have done that for a long time,” he said of Wells’ involvement.
“That is all out my own pocket, but little things like that help you feel good on the field and keep you injury free.
“I think it has paid off. It costs a lot, but in any walk of life, any business, or career, you have to invest your time, money and effort if you want to do things in that career.
“That is what I have tried to do from day one.”