Introducing the Lilyl COI API

A Guide to the Lilly COI API

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The Lilly COI API is an open API (Application Programming Interface) that surfaces data from in Internet-friendly ways using modern web development architecture.

Out of 12,335 APIs on ProgrammableWeb1, only 2.07% are healthcare-related2. And clinical research-related APIs are hardly present at all, accounting for a only .07% of all the listed APIs.3

The Lilly COI API was created to make publicly-available clinical trial information easier to understand and easier for developers to work with.

How the Lilly COI API Works data icon

Regularly import clinical trial data from

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Supplement with location data for clinical trial sites

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Allow for additional trial data

The data is restructured & reorganized into modern web-friendly JSON

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Allow access to individual fields Paginated results Linked location resources

When a developer requests information from the Lilly COI API, it is returned in JSON in a RESTful manner. Developers can then take the data and build it into any web application.

The Lilly COI API allows for granular data requests which can be used to create anything from simple, lightweight widgets to robust, full-featured applications.

How To Use The LIlly COI API

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A developer could build a web application that allows users to choose a disease state and their location to find related trials near them.

The API can be used to return specific trial information to integrate into a website.

Nutrition and Exercise Intervention Study

Status:Open, not recruiting
Sponsor:National Institutes of Health and Nutrition
Last updated:June 9, 2014
View this trial on view the code

To learn more about the Lilly COI API, go to

If you're interested in using the Lilly COI API for your next project, visit for the full API documentation.

  1. ProgrammableWeb API Directory (12,335 total APIs cataloged when accessed on November 10, 2014)
  2. ProgrammableWeb API Directory Category Search: Drugs, Health, Healthcare, Medical, Medical Records, Medicine (255 APIs in this search when accessed November 10, 2014)
  3. ProgrammableWeb API Directory Search for ‘Clinical’ (29 APIs in this search when accessed on November 10, 2014. Data filtered on whether “clinical research” or “clinical trials” were mentioned, also whether the API was related to clinical trials or clinical research even without specifically mentioning the terms)
February 2015 R1.1