Lian Yu herbs are a type of medicinal plant found on the island of Lian Yu.
The Lian Yu herbs have extraordinary healing capabilities, able to help its patient recover from virtually any kind of aliment, including poisoning, drug overdose, infection, etc. These herbs can even counteract potent substances as strong as curare.
In late 2012, Oliver drank a concoction of Lian Yu herbs after being poisoned with a curare-laced bullet. A few days later, he prepared the concoction for John Diggle to also help the latter recover from a curare-laced bullet wound.