I guess i am thrown off a bit with the word "pill". What the term for that? When something is added that distracts attention from the main point? Hmm.. Perhaps you can ask it "Given the choice, would you choose to be mortal or immortal?" A number of anime address this question in one way or another. Tuck Everlasting did too.
Of course, there's immortality with and without invulnerability (Highlander, magic), continuous rebirth (phoenix) or regeneration (DBZ's), and a kill switch (devil's wish).
Hmm...perhaps the question can be asked from another angle: Before accepting immortality itself, i also require (more than anything else):