Liz Takayama is the Japanese author and original creator of the light novel series Parallel World Pharmacy, known in Japanese as Isekai Yakkyoku. Takayama is also credited as the creator behind the subsequent manga and anime adaptations of the same name. The original work is a fantasy isekai series that blends elements of medical drama with world-building, and it has been noted that the author is a practicing pharmacist, a background that informs the detailed pharmaceutical knowledge present in the story.

The creator's primary notable work, Parallel World Pharmacy, began as a web novel serialized online in July 2015 on the user-generated novel publishing website Shōsetsuka ni Narō. The series was later acquired by Media Factory, which published ten light novel volumes from January 2016 to January 2024 under its MF Books imprint. The light novels were illustrated by keepout. The success of the light novel led to a manga adaptation, which began serialization in November 2016 on Kadokawa Shoten's ComicWalker website, with art provided by Sei Takano. As of early 2024, the manga has been compiled into ten volumes.

An anime television series adaptation of Parallel World Pharmacy was produced by the studio Diomedéa and aired from July to September 2022, consisting of twelve episodes. For the anime, Takayama is officially credited as the original creator. The series is licensed for English release by Crunchyroll outside of Asia, and the manga has been licensed for North American release by One Peace Books.

Recurring themes within Takayama's work center on the application of modern scientific and medical knowledge within a fantastical medieval setting. Parallel World Pharmacy follows a researcher who, after dying from overwork, is reincarnated as a young boy in a world where medical practices are primitive and often ineffective. Using his retained knowledge of pharmacology and a divine blessing related to medicine, the protagonist strives to create accessible and effective treatments for the common people, confronting established but flawed medical guilds and superstitions. The series is noted for its treatment of real diseases and medicines, often produced with the guidance of healthcare professionals, which lends an unusual degree of authenticity to its fantasy premise.

The industry significance of Liz Takayama is rooted in the commercial success and multimedia expansion of Parallel World Pharmacy. By July 2021, the light novel and manga together had over 2.3 million copies in print. The property's trajectory from a web novel to a published light novel series, then to a long-running manga and an international anime release, exemplifies a successful modern pipeline for digital-first content in the Japanese publishing industry. Beyond Parallel World Pharmacy, Takayama is also known as the author of another light novel series, Chichi wa Eiyū, Haha wa Seirei, Musume no Watashi wa Tenseisha.