As you already know Oil seal/o-ring wear out and engine oil leak through it, how can you reverse it back!!!  make it grow back like bones!!!

If a properly maintained engine start to leak oil, normally you change to a thinker engine oil... e.g. change from 0W-20 to 0W-30 or 10W-40 etc...
If the leak still continues, then change the seal/o-ring by a good mechanic.  Next is overhaul with top first then full.

Forget about those Treatment Oil, all snake oil

if engine is very old can try use it, why not. it's high viscosity will raise the engine oil viscosity a lil so thicker n heavier oil will leak slower n lesser at low rev low temp. observe white smokes from exhaust if it reduces. it doesn't justify to overhaul a very old engine unless u suddenly got loaded n plan to restore it

can try STP's high mileage engine treatment+stop leak. also try using 20w-50 by next oil change

If leaking from the gaskets and seals, and is visible on the outside of the engine, all of those are replaceable and cost much less than an overhaul.

If the engine oil is burnt and exist the exhaust as smoke, then you could have piston ring, combustion cylinder or valve wear. These needs overhauling.

No amount of oil plugging additive can solve that.

tarik cow better than engine burnt out tarik tow truck

been using engine treatment for decades. if no improvements aint recommending. wanna top overhaul up to u

What engine oil are u using? Brand? Original?

Yeah after 260k km just replaced top gasket on diesel turbo. No burning engine oil. I use the cheapest mineral Caltex Delo 400 or Mobil Delvac.