Act One

Nemorino is in love with Adina but has nobody in whom he can confide, least of all the woman he adores. He is full of admiration for her: she seems to him to be so clever and, above all, so very beautiful. He laments about himself, however, for being stupid and without means. For her part, Adina is interested in what she has just been reading, the story of Tristan and Isolde. She has also taken a fancy to Belcore, one of a detachment of soldiers stationed in the area. Belcore loses no time in proposing marriage to Adina the first time they meet – he urges her rapid acceptance – the wedding tomorrow and back to the battlefield the day after.
Nemorino is now forced to act: he begs for a word with Adina and tells her how desperately he loves her. But Adina rejects him, saying that his feelings are in vain and he should rather look after his sick old uncle.

A glimmer of hope now appears on the horizon for Nemorino, however,  in the person of Dulcamara, who claims to be able to cure all the ailments in the world with his potions. Nemorino asks Dulcamara about the magic potion, an elixir of love, which he has heard Adina reading about in the story of Tristan and Isolde. Dulcamara, who never misses a chance to do business, sells the delighted Nemorino a love potion and promises him that the object of his passion will be his within twenty-four hours. Nemorino has hardly swallowed the elixir – which is a pure Bordeaux – before his self-esteem begins to grow. Nemorino  no longer seems worried  at the thought of Adina’s imminent wedding. This change in Nemorino, his seeming indifference, merely makes Adina defiant. She decides to marry Belcore that same day. Nemorino is horrified as he sees time working against him.

Act Two

As part of the wedding celebrations Dulcamara wants to entertain the guests by singing a barcarolle with Adina; the story tells of how a young gondoliera, Nina, rejects a senator’s wealth in order to marry instead the poor young man, Zanetto, whom she loves.

Nemorino – now under pressure – asks Dulcamara for another dose of the elixir, but Dulcamara will not sell him one for less than 20 scudi and Nemorino no longer has enough money. Belcore, who sees in this a good opportunity to get rid of his rival, offers Nemorino 20 scudi if he will enlist in his regiment. Nemorino signs up with no hesitation.

When the rumour spreads that Nemorino’s uncle has died, leaving him a fortune, he suddenly becomes a good catch as a husband. Nemorino, who still has not heard the news, puts the amazing behaviour of the village girls down to the fact that the potion he has just bought and drunk is working. Adina, who also has no idea that Nemorino has become so wealthy, is astonished to see how popular he is with the girls – and learns from Dulcamara the supposed reason for Nemorino’s behaviour: the elixir. He also offers her a love potion but she declines with thanks – saying she prefers to rely on her own powers of judgement. Out of pity for Nemorino she buys him out of his contract with the military. Nemorino, however, would rather die on the battlefield than live without Adina. Adina finally admits her feelings for Nemorino and breaks her engagement to Belcore, who has no alternative than to follow orders and go off to war. Nemorino is overjoyed and puts his unexpected success with Adina down to Dulcamara’s potion – and the latter is also completely amazed by the miracles which his elixir has brought about.

Place: A small village in the Basque Country
Time: The end of the 18th century

Act 1
Nemorino, a poor peasant, is in love with Adina, a beautiful landowner, who torments him with her indifference. When Nemorino hears Adina reading to her workers the story of Tristan and Isolde, he is convinced that a magic potion will help him to gain Adina's love. The self-important Sergeant Belcore appears with his regiment and immediately sets about courting Adina in front of everyone. Nemorino becomes anxious (although, Adina meanwhile secretly derides Belcore's complacency) and, alone with Adina, reveals his love for her. Yet Adina rebuffs him, saying she wants a different lover every day and following her example would do Nemorino better. Nemorino declares that his feelings will never change. The travelling quack doctor, Dulcamara (the self-proclaimed Dr. Encyclopedia), arrives, selling his bottled cure-all to the townspeople. Nemorino innocently asks Dulcamara if he has any of Isolde's love potion. Despite failing to recognise the name "Isolde", Dulcamara's commercial talents nevertheless enable him to sell a bottle of the cure-all – in reality only cheap wine – to Nemorino, withdrawing all his savings.

To make a safe escape, Dulcamara tells Nemorino the potion needs 24 hours to take effect – by which time, the doctor will be long gone. Nemorino drinks the potion in a haste in order to watch the effect tomorrow. Emboldened by the "elixir" (in fact, drunk), Nemorino feigns indifference when he encounters Adina, as he expects that the elixir will facilitate his conquest of Adina the following day. She becomes increasingly annoyed; perhaps she has feelings for Nemorino after all? Belcore returns and proposes marriage to Adina. Still riled by Nemorino and wishing to give him a lesson, Adina falsely promises to marry Belcore in six days' time. Yet Nemorino only laughs in response: such confidence is sustained in the belief in the magic potion. However, when Belcore learns that his regiment must leave the next morning, Adina promises to marry him before his departure. This of course panics Nemorino, who cries out for Dr. Dulcamara to come to his aid. Adina, meanwhile, invites everyone to the wedding.

Act 2
Adina and Belcore's wedding party is in full swing. Dr. Dulcamara encourages Adina to sing a duet with him to entertain the guests. The notary arrives to make the marriage official. Adina is annoyed to see that Nemorino has not appeared, for the whole deal has been intended only to punish him. While everyone goes to witness the signing of the wedding contract, Dulcamara stays behind, helping himself to food and drink. Having seen the notary, Nemorino appears, depressed, as he believes that he has lost Adina. He sees Dulcamara and frantically begs him for a more powerful, faster-acting elixir. Although Dulcamara is proud to boast of his philanthropy, upon discovering that Nemorino now has no money he changes his tune and marches off, refusing to supply him anything. Belcore emerges, musing about why Adina has suddenly put off the wedding and signing of the contract. He spots Nemorino and asks his rival why he is depressed. When Nemorino says he needs cash, Belcore suggests joining the army, as he'll receive funds on the spot. Belcore tries to excite Nemorino with tales of military life, while Nemorino only thinks of getting the potion and thus winning Adina, if only for a day before departure. Belcore produces a contract, which Nemorino signs in return for the money. Nemorino privately vows to rush and buy more potion, while Belcore muses about how sending Nemorino off to war has so easily dispatched his rival.

After the two men have left, Giannetta gossips with the women of the village. Swearing them all to secrecy, she reveals that Nemorino's uncle has just died and left his nephew a large fortune. However, neither Nemorino nor Adina is yet aware of this. Nemorino enters, having spent his military signing bonus on – and consumed – a large amount of the fake elixir from Dr. Dulcamara. Hoping to share his fortune, the women approach Nemorino with overly friendly greetings. So out of character is this that Nemorino takes it as proof of the elixir's efficacy. Adina sees Nemorino with the women, is rattled by his newfound popularity, and asks Dr. Dulcamara for an explanation. Unaware that Adina is the object of Nemorino's affection, Dulcamara explains that Nemorino spent his last penny on the elixir and joined the army for money to get more, so desperate was he to win the love of some unnamed cruel beauty. Adina immediately recognises Nemorino's sincerity, regrets her behaviour and realises that she has loved Nemorino all along. Although Dulcamara seizes the opportunity to try to sell her some of his potion to win back Nemorino, Adina declares that she has full confidence in her own powers of attraction.

Nemorino appears alone, pensive, reflecting on a tear he saw in Adina's eye when he was ignoring her earlier. Solely based on that, he convinces himself that Adina loves him. She enters and asks why he has chosen to join the army and leave the village. When Nemorino explains that he was seeking a better life, Adina responds that he is loved and that she has purchased back his military contract from Sergeant Belcore. She offers the cancelled contract to Nemorino and reassures him that, if he stays, he will be happy. As he takes the contract, Adina turns to leave. Nemorino believes she is abandoning him and flies into a desperate fit, vowing that if he is not loved he might as well go off and die a soldier. Deeply moved by his fidelity, Adina finally declares that she will love Nemorino forever. Nemorino is ecstatic. Adina begs him to forgive her, which he does with a kiss. Belcore returns to see Nemorino and Adina in an embrace. When Adina explains that she loves Nemorino, the Sergeant takes the news in stride, noting that there are plenty of other women in the world. Adina and Nemorino learn about the inheritance from his uncle. Dulcamara returns and boasts of the success of his elixir: Nemorino is now not only loved but also rich. He exults in the boost this will bring to the sales of his product. As he prepares to leave, everyone queues up to buy the elixir and hails Dulcamara as a great physician.