Information on Erowid's website is gathered from diverse sources including published literature, experts in related fields, and the experiences of the general public.

Although its primary focus is on the website, Erowid Center also provides research and data for other harm reduction, health, and educational organizations.

"[4] Erowid Center's mission is to provide and facilitate access to objective, accurate, and non-judgmental information about psychoactive plants, chemicals, technologies, and related issues.

The library contains over 63,000 documents related to over 737 psychoactive substances,[3][22] including images, research summaries and abstracts, FAQs, media articles, experience reports, information on chemistry, dosage, effects, law, health, traditional and spiritual use, and drug testing.

[26][27] Erowid also runs DrugsData (formerly EcstasyData), an independent laboratory drug checking program co-sponsored by IsomerDesign and DanceSafe.

Erowid has provided expertise and work developing and coordinating the construction of an online psychoactive drug reference library, and MAPS has published a similar collection [33] Erowid Center also archives and provides access to thousands of older texts in their online and physical libraries.

Edward Boyer, an emergency-room physician, and toxicologist, while admitting that Erowid has a plethora of useful information, once argued the site may cause more harm than good to potential drug users.

[35] Anthropologist Nicolas Langlitz argued that Erowid also sometimes serves as a mechanism of postmarket surveillance or pharmacovigilance in the realm of illicit and experimental substances.