Harm reduction, not medical advice. Safety over stigma. Substance testing saves lives.
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OpenSubstance.org
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OpenSubstance is an evidence-based harm reduction resource. It does not encourage drug use. It exists because people use drugs whether or not they have good information, and the evidence is clear that informed users have better outcomes.
All data is sourced from peer-reviewed research, government agencies, and established harm reduction organizations including the Global Drug Survey, The Lancet, DanceSafe, and SAMHSA.
This project is personal. My father, Dr. Mark Depman, spent a good part of his career as an emergency physician in Vermont working at the intersection of substance use and harm reduction. In 2025, the Vermont Association for Mental Health and Addiction Recovery established the Dr. Mark Depman Trailblazer Award in his honor. I grew up watching him advocate for his patients and insist that compassion and evidence, not stigma and punishment, save lives and heal communities.
OpenSubstance is built in that spirit.
— Charlie Depman
The most valuable contributions are data corrections. If you see something wrong — a safety rating, an addiction percentage, a combination rating — we want to know. You don't need to write code.
1. Email corrections@opensubstance.org
2. Tell us which substance and what's wrong
3. Include a source (study, dataset, or article)
We don't change data based on opinions — we need evidence.
Data verification and corrections
New substance profiles with sourced data
Combination mechanism explanations
Sourced — every number traces to a published study or established organization
Conservative — when sources disagree, we use the safer estimate
Honest — we say "unknown" rather than guess
Plain language — no jargon