---
title: ZINC Database
description: 'Query, filter, and download ZINC compounds through the platform workflows.'
tags:
  - zinc
---

ZINC lets you build property-filtered subsets of purchasable compounds and export them for screening or docking. Reach for it when you need buyable molecules in bulk — assembling a focused screening library or a docking-ready candidate pool. For specific hits, ask Ivy in chat for a ZINC lookup: it returns the vendor catalog codes you need to confirm supplier availability and pricing. ZINC lookups run only inside a chat turn; there is no form, job or CLI command for them. See [what you can achieve](/docs/capabilities#chemistry).

## What ZINC provides

ZINC is a free resource of commercially available compounds for virtual screening, developed by the Irwin and Shoichet Laboratories at UCSF. The latest major version, **ZINC-22**, offers unprecedented scale:

- **37+ billion** enumerated compounds searchable in 2D (make-on-demand libraries).
- **750+ million** purchasable compounds with 3D representations, including ready-to-dock catalogs from **Enamine REAL**, **WuXi GalaXi**, and **Mcule Ultimate**.

The chat lookup works by SMILES or ZINC ID and returns up to 1,000 compounds at a time. A bulk, property-filtered subset (drug-like, fragment-like, lead-like) is a different job: Ivy pulls it from ZINC's CartBlanche22 service and filters it with RDKit in the chat's [code workspace](/docs/sandbox), and the guides below show that code. See the [quickstart](/docs/zinc/quickstart) for the full citation and a first search.

## Citations

> Tingle BI, Tang KG, Castanon M, Gutierrez JJ, Khurelbaatar M, Dandarchuluun C, Moroz YS, Irwin JJ. ZINC-22—A Free Multi-Billion-Scale Database of Tangible Compounds for Ligand Discovery. *Journal of Chemical Information and Modeling*. 2023;63(4):1166-1176. doi: [10.1021/acs.jcim.2c01253](https://doi.org/10.1021/acs.jcim.2c01253)

## Guides in this section

## ZINC-22 operations

Ask Ivy in chat for any of these:

- **Search by SMILES** — an exact match, or close analogs by graph edit distance (1-4 is the useful range), up to 1,000 results. This is not a Tanimoto similarity or substructure search.
- **Look up ZINC IDs** — up to 100 IDs at once; returns SMILES, vendor codes and catalog names.
- **Check vendor catalog codes** — up to 100 codes at once (for example `EN300-19380`); returns the matching ZINC IDs and SMILES. For prices, Ivy runs a separate vendor price search; see [compound procurement](/docs/workflows/compound-procurement).

## Where it fits

ZINC compounds feed docking with [DiffDock](/docs/diffdock), ADMET screening with [ADMET-AI](/docs/admet-ai), and synthesis feasibility with [AiZynthFinder](/docs/aizynthfinder). It accepts SMILES from [PubChem](/docs/pubchem) and generative tools for analog search, and its outputs populate the Compound Passport.

## FAQ

### What outputs can I expect?

  ZINC IDs, SMILES, vendor codes and basic properties in chat. CSV and 3D SDF files come from code Ivy runs in the chat's code workspace.

### How big are typical downloads?

  Filtered subsets range from thousands to millions of compounds; chunk large exports to stay under storage quotas.

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