ACT ONE

Adina reads aloud a book of fables, accompanied by her friend Gianetta and some other townspeople.  They are observed by Nemorino, who is in love with Adina.  Coming across the story of Tristan and Isolde, Adina reads with laughter how Tristan won Isolde's heart by drinking a magic love potion.  A drum roll announces the arrival of the rather conceited Sergeant Belcore, who immediately proposed to Adina; amused, she says that she will consider it.  After everyone leaves, Nemorino awkwardly declares his love to Adina.  She tells him his time would be better spent looking after his ailing uncle than mooning over her, for her heart is capricious.

A "doctor" by the name of Dulcamara arrives, telling the townspeople about the magic medicines he sells.  Since it is cheap, the villagers buy happily.  After the villagers leave, Nemorino asks Dulcamara if he sells the elixir of love described in Adina's book.  Dulcamara claims he is in possession of that very item, and takes all of Nemorino's money in exchange for a bottle of wine.  He warns Nemorino that the potion will take effect 24 hours after he drinks it and that it must remain a secret.  Nemorino drinks the entire bottle right away.  Adina returns to find him tipsy; certain of winning her love, he feigns indifference.  Insulted by his apparent change of heart, Adina flirts with Belcore, who, informed that he must return to his garrison, persuades her to marry him at once.  Nemorino begs Adina to postpone the wedding for at least one more day, but she ignores him and invites the entire village to her wedding feast.  Nemorino rushes away, moaning that he has been ruined by Dulcamara's elixir.

ACT TWO

At a pre-wedding feast, Dulcamara sings a barcarole with Adina about a gondoliera and her wealthy suitor.  Adina and Belcore go off to sign the marriage contract and the guests disperse.  Nemorino begs Dulcamara for another bottle of elixir, but because he cannot pay, Dulcamara refuses.  Belcore returns, frustrated that Adina has postponed the wedding until the evening.  Hearing of Nemorino's financial plight, he persuades the boy to join the army and receive the bonus due all new recruits, which he can use to buy another bottle of elixir.  Belcore is pleased to have both enlisted another soldier and removed his rival for Adina's heart.

Giannetta tells the village girls that Nemorino's uncle has died and left him a fortune.  When the youth reels in, giddy from a second bottle of wine, they besiege him with attention.  Unaware of his new wealth, he believes the elixir finally has taken effect.  Adina and Dulcamara arrive in time to see him leave with a group of girls, and she, angry that he has enlisted in the army, grows doubly furious.  Hoping to sell Adina a bottle of elixir, Dulcamara claims that Nemorino's popularity is due to the magic potion.  Adina replies she will win him through her own charms.  Reentering alone in a pensive mood, Nemorino takes heart because of a tear he has seen on Adina's cheek, but when she appears, he acts disinterested.  She confesses she bought back his enlistment papers because she loves him.

Belcore returns to find Adina affianced to Nemorino; he accepts the situation philosophically, declaring that thousands of women await him.  Attributing Nemorino's happiness and inheritance to the elixir, Dulcamara quickly sells more bottles before leaving town.