Setting: A bucolic village in the early nineteenth century
Act I
As the peasants rest, the lovely and wealthy Adina reads to them. She is amused by the story of Tristan drinking a potion that makes Isolde fall in love with him. Listening from a distance, Nemorino admits he adores Adina. The conceited Sergeant Belcore arrives and proposes to Adina, who does not give an answer. Nemorino approaches Adina, who tells him to go and live with his rich but ailing uncle. When she insists that he should forget her, he replies that he exists only to love her.
In the village square, Dr. Dulcamara hawks a cure-all potion to the peasants. Nemorino naively asks for Tristan's love potion from Adina's story. Dulcamara sells Nemorino a bottle of Bordeaux, telling the young man the potion will take effect the next day. Adina comes upon Nemorino, who no longer seems eager to pursue her. Perturbed, Adina agrees to marry Belcore. When Belcore receives orders to leave the next day, he asks Adina to marry him that very evening. Although Nemorino implores Adina to wait, she invites all the village to her wedding.
Act II
The notary arrives at Adina's farmhouse where everyone is celebrating the impending marriage. Nemorino arrives and asks Dulcamara for another love potion, but the doctor refuses because the young peasant has no money. The Sergeant convinces Nemorino that joining the army will solve his money woes. Nemorino signs a contract and, with the money Belcore gives him, runs off to find Dulcamara. The peasant girls receive news that Nemorino's uncle has died, leaving him a fantastic inheritance. Nemorino appears and, when the girls shower him with affection, believes the potion has taken effect. Adina is upset to discover Nemorino enjoying their attention. The doctor tries to sell her some of the elixir, but she refuses, confident that she can win Nemorino without it. Beauty is her elixir. Having purchased his contract from Belcore, Adina confesses to Nemorino that she loves him.
Dulcamara announces that Nemorino's uncle has died, making the young peasant the village's richest squire. The Doctor credits his elixir with Nemorino's good fortune, and the peasants eagerly ask for it.