Summary

• Yidu's Chinese medicine in Vikings is powerful and addictive, but its exact ingredients are unknown and not as straightforward as opium.
• Yidu's harsh background suggests that her medicine likely includes more ingredients than just opium, potentially including psychedelics like psilocybin or DMT.
• Ragnar's addiction to Yidu's medicine had a significant impact on his life, driving him away from his family and contributing to his downfall.

Vikings introduced Yidu (Dianne Doan) in season 4, and with her one of the most mysterious aspects of the show — the Chinese medicine in Vikings that helped Ragnar manage his intense pain. Legendary warrior Ragnar Lothbrok (Travis Fimmel) was the key focus of Vikings until his death in season 4. Ragnar’s story was full of ups and downs, especially in his personal life, and some details about it left many questions, such as his relationship with Yidu, who made him addicted to a mysterious drug believed to have been opium.

After Ragnar’s death in season 4, his sons – Björn, Ubbe, Hvitserk, Sigurd, and Ivar – took over Vikings and led the series until its final episode, but Ragnar’s presence could still be felt. Ragnar had drowned Yidu before his own death, which meant the mystery of the Chinese medicine in Vikings was never revealed. While many initially suspected the addictive substance was opium, the answer is nowhere near as straightforward.

Yidu's Vikings Drug: What Was It?

The Chinese Medicine In Vikings Probably Wasn't Opium

Yidu's ancient Chinese medicine in Vikings is clearly powerful, potent, and addictive. This has led many viewers to believe that Yidu gets Ragnar addicted to Opium. However, the answer to what Yidu's medicine is likely doesn't have as simple an answer. Based on Yidu's drug having a strong psychedelic effect, the variety of plants that Yidu cuts and grinds onscreen, and Yidu's background, there's no single and straightforward answer to this question.

Ragnar and Yidu ended up becoming lovers after he semi-freed her, and she gave him a drug to alleviate the painful effects of Ragnar's illness after the Siege of Paris. It appeared this was kidney damage due to the symptoms he was having (discomfort in the abdomen, nausea, and urinating blood). The drug's pain-alleviating and hallucinogenic effects have led viewers to conclude that it was opium. It's certainly possible that the Chinese medicine in Vikings is some form of ingested opiate.

Yidu first appeared in Vikings season 4 as one of the slaves captured in Frankia and the only Asian girl among them. As she looked different from the rest, she caught the attention of Aslaug (Alyssa Sutherland). Aslaug bought her, and she later caught the attention of Ragnar, as well. Yidu eventually revealed a bit about her backstory, sharing that she was the illegitimate daughter of the Chinese Emperor and that pirates had captured her and her brothers, later selling her into slavery. Yidu's harsh but well-traveled background suggests she would have used more ingredients than just opium.

Yidu actress Dianne Doan also played Mai Ling in the Cinemax martial arts drama Warrior.

Is Yidu's Vikings Drug Historically Accurate?

The Ambiguity Surrounding The Ancient Chinese Medicine In Vikings Safeguards Against Inaccuracy

While Vikings' historical accuracy isn't always perfect, in this case, the ambiguity of what drug Ragnar takes with Yidu does line up with what little is known about widespread ancient psychedelic use. Notably, with the drug being folded into a leaf and Ragnar's red saliva, some have theorized that it could be kratom or even betel nut.

However, while these are common in China/Southeast Asia and would be available to Yidu, betel and kratom are stimulants and not psychedelics. What's more likely is that Yidu's medicine included not only opium but possibly also psilocybin or even DMT, the traditional preparation of which is consistent with the variety of Yidu's herbs. While the specific ingredients are unknown, the fact that a woman like Yidu could concoct incredibly potent pain-relief definitely isn't.

What Happened To Yidu In Vikings?

Yidu Met An Terrible Fate Thanks To Ragnar

Whatever combination of drugs Yidu gave Ragnar in Vikings season 4, the legendary Viking warrior became addicted to it, and it helped him cope with the pain, but this also led to Yidu’s tragic fate — one of Ragnar's most unforgivable Vikings scenes. Ragnar started to demand more and more “medicine” from her, and it got to a point where she eventually refused him, leading to an argument between them and Yidu threatening Ragnar with revealing his Wessex secret.

In a fit of rage, Ragnar drowned Yidu. Ragnar’s drug problem in Vikings season 4 also drove him further away from his family, affected his leadership, and contributed to his downfall. While the ingredients of Yidu's medicine are a mystery, it's clear that its addictive qualities had a significant impact on Ragnar.