Eat less, exercise more. Works at every age. Free. Proven effective for centuries. Near zero side effects.
A more ketogenic diet.
Otherwise, what I have seen "work" is curcumin and cbd oil. Curcumin has helped some old people I know deal with pain related to inflammation. CBD oil relieves seems to relieve stress, and pain, and is relaxing, which has helped some seniors I know live better and sleep better.
Some others that are worth trying are D3 and B12 (sublingual). D3 production drops as we get older. People also absorb much less B12 through the gut as they get older.
Also, I recently gave my parents some Senolytic Activator.