If love is a drug, then Romeo and Juliet pushes that belief to its extremes. You might have noticed that the play’s third biggest role after the lovers is Friar Laurence, the play’s would-be pharmacist. But why is the Friar so interested in drugs and home cures, and what part do they play in Shakespeare’s tragedy?

As most of us know, harmful substances can be medicinal in small doses, and this was understood in Shakespeare’s day too. When we have injections to prevent us from getting certain diseases, that injection actually contains a tiny dose of the disease itself—it’s small, but it’s just enough to kick-start our body into fighting it off and make us immune to the illness. Our familiar word ‘pharmacy’ suggests how both poison and cure are connected: it comes from the Greek word ‘pharmakon’ and means both toxin and remedy.

How might we use this idea to think about Romeo and Juliet?

Like a pharmacist, Shakespeare is interested in substances that can be both healthful and deadly. When Romeo is feeling love-sick over Rosaline, Benvolio encourages him to cure himself by seeking out more poison: ‘take thou some infection to the eye / And the rank poison of the old will die’. In appropriately pharmaceutical terms, something that seems harmful can actually be restorative. Health, in other words, can be achieved via illness. After all, this is a play that seems to tell us that good can arise from harm— Juliet’s ‘only love’ springs from her ‘only hate’—but the flip-side of that means that too much of a good thing can also be harmful. As Friar Laurence warns, ‘these violent delights have violent ends’.

As far as the Friar’s concerned, he’s offering Juliet a cure that will ‘remedy’ her situation. But, as we’ve already seen, the medicinal in this play is often only a small step away from the poisonous. It’s perhaps not surprising given the Friar’s pharmaceutical interests, then, that in order for this medicinal cure to work, it actually behaves like poison—stopping Juliet’s pulse and breath, draining the colour from her cheeks, and making her body ‘stiff and stark and cold’. Even if it’s only temporary, this is a medicine that will in a sense actually kill Juliet, and it’s no wonder that she worries about the remedy being a ‘poison which the Friar subtly hath ministered’ to kill her. In a play that makes clear just how blurry the line between toxin and cure can be, Juliet seems to be well aware of the risk she’s taking.

As we know, things don’t exactly go to plan. The letter to Romeo that explains the Friar’s plot fails to arrive in time, and Juliet’s death-like state proves to be too convincing. In the end, Romeo is driven to mirror Juliet’s actions. Remember that Romeo also uses a language of toxic cure when he kills himself, thinking Juliet has died: ‘Come, cordial, and not poison, go with me to Juliet’s grave; for there must I use thee’. Romeo no longer sees a difference between poison and remedy. For him, poison is a medicinal drink, and playing on the Latin word for heart (‘cor’ or ‘cord’), the broken-hearted Romeo finds that poison as the only thing able to heal him.

Like the Friar’s ‘weak flower’, and like Juliet’s ‘remedy’, Romeo’s ‘cordial poison’ contains a powerful mixture: it has the power to do harm, but also has the potential to heal. Perhaps it’s for this reason that when Juliet wakes up, she also talks about Romeo’s poison not as something that is straightforwardly harmful, but rather as a ‘restorative’ that will end her life. Of course these ‘restoratives’ are lethal to Romeo and Juliet, but as the play makes clear, their death is the remedy that is required to cure Verona’s ‘ancient grudge’ and ‘their parents’ strife’.