I believe that a confusion of names and purposes (not really your own) leads to your question. Seekers of the so-called Elixir of Life (sometimes Water of Life) and of the Philosopher's Stone each had one or both of these objectives. The latter had to be ingested in order to achieve immortality — an effect 'proved' only with difficulty and the passage of time — but either needed only to touch the base metal to turn it into gold on the spot. Any investigation of immortality was always going to be problematical, which is probably why transmutation was more eagerly sought, for everyone could easily accept that gold made you rich. I think it very doubtful that anyone claiming to practise alchemy was anything but a charlatan, but there are one or two exceptions — principally that of Isaac Newton, whose willingness to pursue alchemy, in apparently violent contrast to his mathematical and scientific contributions, is excused for its supposed objectivity by his apologists.
It's almost as if the alchemist sought simply to be rich and immortal, though the prospect of consequent power (or, at least, profit from trickery) must have driven some, rather than enlightenment. The name that you gave to the means was not really material: either would do the job. The task of discovering the means was known as the magnum opus (understandably enough, though I'd have thought something as ambitious as that was worth a superlative!), whether you were looking for the Lapis Philosphi or the Tinctura Physica/Aqua Vitae.
