olenna tyrell queen of thorns highgarden the reach poison

We’re almost halfway through the penultimate season of ‘Game of Thrones,’ and yet again, Westeros has poison on its mind. But just because HBO’s fantasy epic takes place in another dimension where magical things happen doesn’t mean that the poisons described aren’t astonishingly realistic and scientific.

There are spoilers for Game of Thrones Season 7, Episode 3 below.

In “The Queen’s Justice,” Jaime Lannister commands a massive invasion force against Olenna Tyrell and the remainder of her forces at Highgarden.

After the off-screen battle, Olenna accepts a gift from Jaime: a glass of poison that he promises will give her a quick and painless death. Olenna chugs her poisoned wine and signs off with the best mic drop of the entire show, revealing to Jaime that she was the one who killed his son, Joffrey, by putting a different poison called the Strangler in his drink.

jaime lannister highgarden poison the reach season seven episode three
"Are you kidding me?"

We don’t know what poison Jaime gave Olenna, but there are a number of poisons in the realm of Game of Thrones that correspond to real life.

Sweetsleep — Fictional

One of the most likely candidates is sweetsleep, which according to the books by George R. R. Martin, can act as a soothing agent in very low doses: Just three pinches of the stuff will make people fall asleep and never awaken. It has a sweet taste that would have made it the perfect complement to Olenna’s goblet of wine. It’s described in the lore as the gentlest poison there is.

Essence of Nightshade — Fictional

Olenna also could have been given essence of nightshade. Essence of nightshade is a powerful, fictional substance often used as a sedative, but just ten drops of it can be lethal. Once more, people poisoned by essence of nightshade will feel relaxed and sleepy before they succumb — no pain at all.

cersei lannister tommen baratheon iron throne blackwater essence of nightshade poison
Cersei prepares to mercy kill her son, Tommen, while the castle is under seige.

Essence of Nightshade — Real

Interestingly enough, the real-world poison derived from the nightshade plant, Atropa belladonna, is very different. People who have taken Belladonna describe horrific hallucinogenic trips that have allegedly made many people swear off recreational drug use. If we were going for scientific realism here, then it’s less likely that this was the poison Jaime Lannister gave Olenna Tyrell.

Prescription Barbiturates — Real

Seconal and Nebutal are two types of barbiturates — often prescribed as sedatives and insomnia treatments — are frequently used by people looking to commit suicide via drug overdose. As in sweetsleep, people who take them will feel sluggish before ultimately passing out and sometimes dying.

Barbiturates work by depressing the central nervous system. Basically, they slow down your brain’s function. When barbiturate molecules come into contact with the brain, our neurons mistake them for molecules of GABA, the naturally-occurring neurotransmitter that inhibits neural function. Basically, our brains treat a dosage of barbiturates like an off switch.

However, because it takes an active effort to overdose on these sleeping pills, Olenna probably drank something a little more powerful.

Lethal Injection Barbiturates — Real

As Helen Keen writes in “The Science of Game of Thrones,” there are two particular drugs that have been administered during legal executions that allegedly cause a sudden, painless death.

Sodium thiopental was invented in 1934 and replaced around 2011 with pentobarbital, which became more restricted in 2016. Sodium thiopental, in low-enough doses acts as the oft-fictionalized truth serum. Very high doses were used in lethal injections. When injected, people quickly passed out and died. It can also be used at a lower dosage in euthanasia to induce a coma before being mixed with a drug like Pavulon, which blocks signals from the brain. Pentobarbital, like sodium thiopental, is another fast-acting, potent barbiturate that can also be used as an emergency seizure treatment and can knock people out before surgery.

wolfsbane flower plant
Wolfsbane IRL.

Wolfsbane — Real and Fictional

In addition to the sleepytime drugs above, he could have given her wolfsbane, which is capable of killing people rapidly and seemingly-painlessly in ‘Game of Thrones’ and in real life when made from plants of the Aconitum genus. Rather than a barbiturate, it’s more likely that fictional wolfsbane and perhaps even manticore venom could have been used to kill Olenna by acting as a paralytic agent — a chemical that can stun the heart or lungs as soon as it reaches them.

If you are having suicidal thoughts or struggling, please reach out to the National Suicide Prevention Lifeline.