Release notes, March 2026Release date: March 26, 2026Reaxys contains millions of expertly curated chemical reactions, capturing published methods to synthesize compounds that are not commercially available....

Expanded Retrosynthesis Prediction with Published Routes Integration

Release Notes for February 2026Reaxys now offers AI-enhanced document search and literature summarization, combined with a refreshed user interface. These enhancements help chemists find, understand, and...

AI-enhanced Quick Search and literature summarization

This video showcases how Reaxys helps you to get the best out of your research. 


Welcome to Reaxys

Marvin JS, an integrated chemical sketcher, which allows quick, convenient drawing and modification of chemical structures. Learn how to utilise its wealth of tools within these tips and tricks. 


Tips for using Marvin JS

Review details of our latest releases. All current and past notes are available here.

Reaxys Release Notes

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	New User
	
	
		Go to Reaxys.
		Click “Sign in via your institution”.
		Enter and select the name of your institution/organization.
		You’ll be prompted to sign in using your institutional...

How do I sign in/register through my institution/Single Sign-on (SSO) access in Reaxys?

In this release we are excited to introduce Reaxys AI Search, your new tool designed to explore chemistry literature using natural language queries. This early AI-supported improvement aims to make Reaxys...

Reaxys AI search: Document discovery through natural language querying release notes for July 2025

You can search Reaxys using Quick Search, Query Builder, via batch searches or link-in searches. While Quick Search and Query Builder do not require any special knowledge about search field codes, using...

Which search and export fields are available in Reaxys?

There are three search options available within Reaxys:


	Search with the ‘Quick search’ option.
	Use the ‘Query builder’.
	Browse through your saved searches and recent searches.


Quick tip: You can...

How can I search in Reaxys?

You can create complex queries with the Query builder by:


	Using a free form approach (find, select and combine search fields, recent searches and saved searches as desired).
	Using search forms available...

How do I search with the Query builder?

Reaxys supports the execution of several queries in a batch of up to 1000 queries per batch. The searches are imported in Reaxys in either SD (collection of several molfiles) or textfiles (one advanced...

How do I create a batch query?

Reaxys is a Java-free application. It works on both MAC and Windows

What are the technical requirements for Reaxys?

Reaxys has integrated the Java-free editor Marvin JS from ChemAxon and ChemDraw JS from Perkin Elmer into its interface. Both tools can accept structures copied from external structure editors. For more...

Can I use an external Structure Editor?

How to define a structure query for substances and review substance records for a given compound.


Search for substances by structure

For more information, view our Terms & Conditions. Reaxys allows authorized users to export content and use it to drive your research projects. There are however some restrictions that apply:

Authorized...

How can exported data from Reaxys be used?

How to retrieve documents for a topic or target of interest and how your terms are searched in English and non-English titles, abstracts, indexed terms and patent claims.


Search for literature

The Reaxys Group Generics tool is used to define acyclic groups and cyclic groups, while the Query Atoms tool is used to define atom generics.

These predefined generic groups are recognized by Reaxys...

How do I define Reaxys Generic Groups?

How to search for substances by name or formula and review substance records for a given compound.


Search for substances by name

Reaxys has a new step-by-step guided export function, which is easy to find and intuitive to use.

Please note:


	It is not possible to run exports as an anonymous user. Once the export feature has been...

How do I export results?

You can filter your results to limit the entire set of search results to only the results you want to see. Depending on the results’ context, different filter categories will be presented.

See our different...

How do I filter my search results?

Reaxys results views are context dependent. A substance results view will provide tools, filters and data views that are suited for handling substance data, while document and reaction results view will...

How do I view my results?

Your user profile includes the following information:


	Your account information:
	
		Your username, password and email address
	
	
	Your profile information:
	
		You first and last name
		Your job title,...

How can I personalize or change my user profile and preferences?

This Video Tutorial describes how to create a Structure Drawing. The tutorial is divided in the following chapters which allow you to skip to the parts most interesting to you:How to create a Structure...

Video tutorial: How to create a Structure Drawing in Reaxys

You can set up email alerts to notify you of new articles or publications related to a specific search.To create an alert, you have to be logged in to Reaxys.
How
Follow these steps to create an alert:
From...

How do I create email alerts?

Reaxys makes use of various taxonomies for tagging content and providing support for filtering search results in Quick search and in the Query builder.

Taxonomies are hierarchically organized controlled...

How is my search supported by taxonomies?

Reaxys saves all session search results including filter operations on a page called ‘History’. 
The 'History' page has two tabs: 

‘Recent’ - lists all the  search results including filter operations...

How can I save my searches?

This release focuses on the user experience by introducing the option to ignore stereochemistry and automating the re-launch of jobs with extended parameters, reducing instances of no results found.

Ignore...

Reaxys Predictive Retrosynthesis powered by Iktos release notes for April 2025

Citing articles are articles that have the selected article mentioned as a reference within the document. A higher 'cited by' number means more authors have cited the selected article. 
How
Follow these...

How do I view citing articles?

There are several ways to search for Target and Bioactivity data using the Query builder.


	Build a query from scratch using individual fields.
	Build a query from the Target and Bioactivity field section...

How do I search for substances using Reaxys Target and Bioactivity?

Click here to view our logo on a separate website and download it from there.

For a different size or format, contact us through our webform.


How can I add the Reaxys logo to our website?

You must be logged into Reaxys to edit an alert.

Several parameters of an alert can be edited without creating a new one, e.g. changing the alerting frequency. However, if the alert query itself needs...

How do I edit my email alerts?

If you use New Reaxys (https://new.reaxys.com) then you don't have to install Java. 

New Reaxys only supports Java-free structure editors like Marvin JS due to all modern browsers limiting Java-based...

Do I need to install Java to use Reaxys?

Reaxys supports synthesis planning in various ways. While a simple search for a substance (as single structure or as part of a reaction) retrieves reaction information (preparations or reactions), if available,...

How can I do Retrosynthesis?

Reaxys Predictive Retrosynthesis powered by Pending.AI 

This release focuses on improving retrosynthesis predictions, providing diverse routes faster thanks to an updated model and service as well as...

Release notes for October 2024

Reaxys' rich and comprehensive collection of experimental and analytical data helps users to make better decisions faster. Exporting data of interest in various formats and using it in subsequent research...

Video tutorial: Exporting in Reaxys

Yes, you can access Reaxys on mobile devices such as tablets and mobile phones using your mobile browser (i.e. Chrome, Safari, Firefox). Currently Reaxys does not have its own app for mobile devices.

Reaxys...

Can I access Reaxys on my mobile device?

Yes, Reaxys supports the use of wildcards in the following ways:
Quick Search
Quick Search supports the asterisk (*) as wildcards. It can be set at the beginning of a word (corresponds to a search “ends...

Does Reaxys support wildcards?

The Bioactivity visualizaton map (formerly known as Heatmap) view is available for all queries in substances, target and documents result pages. It initially provides an overview on structure activity...

What is a Bioactivity visualization map?

In this example, let’s find which ligands have been tested as agonists of the 5-HT6 receptors. 


	Click Query builder
	Retrieve the Affinity on target form
	
		In the Find search fields and forms field,...

How do I find which ligands have been tested as agonists?

Yes you can export the raw data like substances (Names, Smiles etc.) targets (Names, Species, mutations, etc.), cell lines, Bioassays and bioactivities (pX, IC50, Ki, etc.) that are used to construct and...

Can I export the Heatmap?

A similarity search can be used to find substances or reactions that are similar, but do not meet all criteria of the query structure:A compound/structure is said to be similar if the new structure's behavior...

How do I perform a similarity search?

Abbreviated groups are a powerful feature of Marvin JS, which helps to draw structure queries quickly and efficiently: using a short text abbreviation you can get a functional group, a ring or other structure...

How do I add an abbreviated group template?

You can search for substances or reactions using Quick search or the Query builder.

To learn more on performing a general search in Reaxys, visit our articles on:

How to search
How to search with the...

How do I search for substances or reactions?

Reaxys supports various operators in Query Builder. If you have dropped multiple fields (querylets), forms or items from your history into the Query Builder panel, they will be “connected” with a drop-down...

How do I use Boolean Operators in Reaxys?

More enhancements to the discoverability of relevant documents

Spend less time on reviewing document results thanks to grouping of similar patent documents …

… and faster access to Reaxys curated information...

Release notes for November 2024

The Link-In feature allows you to link to Reaxys from other applications and documents. It can be used to configure in-house applications to call Reaxys (i.e., open the relevant Results page in the default...

How do I use the link-in feature?

Dissociation constant, also called dissociation exponent (pK or pKa, for acids) can be calculated by following the below steps:

How

From Quick Search


	Draw the substance of interest and search. 
	Go...

How can I filter on pK or pKa values of a substance?

This release brings to you new enhancements for Reaxys patent content.

Explore substance information from patents across diverse subject areas

You now can now find chemical substances, their structures...

Release notes, February 2024

Reaxys has embedded Marvin JS, a Java-free editor provided by ChemAxon. This tool allows you to create structure and reaction drawings and supports all Reaxys search means. 
How
Follow these steps to draw...

How can I draw a reaction or structure?

In this example, let’s look at how to find selective molecules on Prostaglandin G/H synthase 2 (COX-2) versus Prostaglandin G/H synthase 1 (COX‑1)?


	Click Query builder
	In the Find search fields and...

How do I use the Selectivity Profile form in Query builder?

In the Reaxys heatmap, pX values provide an interactive matrix that summarizes affinity for a large number of compound–target pairings and can be used to explore factors that contribute to affinity or...

How is pX calculated in Reaxys?

This Fact Sheet contains key information on the benefits of patent content expansion in Reaxys and is a brief overview of the phased releases in an easy to view one-page summary.


Reaxys Patent Expansion

Faster, More Accurate, and Diverse Route Predictions with Expanded Substance Libraries and Pending AI EnhancementsIn this release, we have expanded the commercial substance libraries and enhanced the Pending...

Release Notes for June 2025

In Reaxys, you are able to view overlapping structures by viewing the structure in 3D.
How

From your structure, click on the magnifying glass icon.


Click 'View in 3D'.


Click on 
to zoom in, zoom out,...

How can I view overlapping structures?

How to find reactions by building a graphical reaction query.


Reaction by Structure

Alert emails set up for the Reaxys database now include greater detail, including abstracts, structures, reactions and targets. This makes it easier to establish the relevance of the new information.

Each...

How do I use Reaxys alerts?

Reaxys helps you design compounds with toxicology, efficacy and SAR insights from over 44M bioactivity data points. This video shows you in a few simple steps how to find out if your scaffold is cytotoxic.


How to avoid structural motifs with known safety issues?

How to search for named reactions and find preparation details from text searching.


Reaction by Name

Reaxys allows you to search through the literature by author name.
How
Follow the steps below to search for an author’s literature:

Go to ‘Query Builder’.
In ‘Find search fields and forms’, type Author.
Select...

How do I search by author name?

When you draw a molecule in the ChemDraw JS structure editor, Reaxys allows you to name your molecule.
How
Follow the steps below to name a drawn molecule:

Go to ChemDraw JS structure editor.
Draw the...

How do I name a drawn molecule in Reaxys?

This video tutorial describes how to use the Query builder and how to refine your search. The tutorial is divided in the following chapters which allow you to skip to the parts most interesting to you:...

Video tutorial: Using the Query builder in Reaxys

This release focuses on improving the retrosynthesis predictions by updating the model and on enhancing the user experience by automating the re-launch of jobs with extended parameters, reducing instances...

Reaxys Predictive Retrosynthesis powered by Pending.AI release notes for April 2025

Reaxys helps you design compounds with toxicology, efficacy and SAR insights from over 44M bioactivity data points. In a few simple steps this video shows you how to review active compounds for your target of interest.


How to assess the chemical space for your target?

This Fact Sheet contains key information on the transition from ‘Synthesis Planner’ to ‘Reaxys Retrosynthesis’ and is a brief overview of the major updates and changes in an easy to view one-page summ...

Reaxys Retrosynthesis Feature

Improved Retrosynthesis functions and easier access to relevant substance dataGuided by our customer’s feedback, we are continuously improving our recently launched Retrosynthesis feature with new functionalities...

Release notes for December 2021

Further advancements in Patent discoverability and strategic insightsWe know from your feedback that patent discoverability for competitive intelligence analysis is important, particularly if you’re interested...

Release notes for January 2022

Additional improvements to CAS registry number search Continuing on from our enhancements to better support search and retrieval of CAS registry numbers (CAS RN), and inpartnership with CAS, we have enabled...

Release notes for February 2022

Guided by customer feedback, Reaxys is continuously improving the Predictive Retrosynthesis module and our Retrosynthesis feature, so users can have better options for project management and collaboration.What...

Release notes for March 2022

Improvements to user experienceThe Reaxys Team continue to strive to make improvements to your experience within Reaxys. This release focuses on some key areas which were identified by the scienftific...

Release notes for May 2022

The Reaxys Team continue to strive to make improvements to your experience within the product. This release focuses on improving some Predictive Retrosynthesis functionalities:  Updates to Retrosynthesis...

Release notes for June 2022

This release focuses on introducing a new way to set your preferred chemical suppliers and specifically access information from their catalogues. Additionally, now it is easier to modify your queries in...

Release notes for January 2023

This release focuses on introducing improvements to the shipping information related to commercially available chemicals. In addition, the Reaxys Medicinal Chemistry (RMC) database has been renamed as...

Release notes for February 2023

Release notes for Bioactivity Visualization ExportAddition of new layout for the Bioactivity Visualization excel exportIn order to better support bioactivity data screening, competitive and novelty search...

Release notes for November 2023

Enhanced multi-step reaction navigation for more efficient synthesis planningReaxys supports multi-step reactions by linking together single-step transformations that are reported within the same publication....

Release Notes for December 2025

The Substance Similarity Score is calculated using a proprietary algorithm. It is based on a Tanimoto-type similarity comparison between structural feature vectors derived from both the query structure...

How is the Substance Similarity Score calculated?

Reaxys helps you to quickly decide between making or buying a compound, with high-quality reaction data and over 315M commercial products. This video shows you in a few simple steps how to find supplier information for your compound.


How to quickly obtain a commercial substance?

This release focuses on improving visibility on where substance results are coming from with the introduction of database tabs. Furthermore this brings additional benefit of being able to move across different...

Release notes for April 2024

This release focuses on content enhancements for Reaxys Journals and Patents.Journal content expansion and substance extraction from imagesReaxys continues to use its award-winning AI-driven data extraction...

Release notes for August 2023

More content for Competitive Intelligence and Novelty SearchResponding to your feedback and recognizing the importance of incorporating extensive patent content into Reaxys, we are delighted to announce...

Release notes for July 2023

This release focuses on some feature improvements on Reaxys Predictive Retrosynthesis.Using Break or Protect Bond definitions for Retrosynthesis ProjectsReaxys  predictive  retrosynthesis supports the...

Release notes for July 2023 

This release focuses on a new feature for sorting substances by their similarity score, helping to identify the commercial availability of similar substances, accelerate synthesis planning, and stay on...

Release notes for May 2025

Improved competitive intelligence thanks to major patent content expansionFeedback from Reaxys users and the broader research community is important to our development plans. Patent searchability is a...

Release notes for February 2021

Reaxys helps you design compounds with toxicology, efficacy and SAR insights from over 44M bioactivity data points. This video shows you in a few simple steps how to obtain structure-activity relationship data for all compounds in a patent.


How to obtain SAR data for compounds in a patent?

The Reaxys Team continue to strive to make improvements to your experience within the product. This release focuses on improving some Retrosynthesis functionalities:  Enriched information about commercially...

Release notes for August 2022 

Reaxys helps you design compounds with toxicology, efficacy and SAR insights from over 44M bioactivity data points. This video shows you in a few simple steps how to identify differences between the original and current patent assignee for your scaffold.


How to avoid competitor blindspots?

This release focuses on improving discoverability of relevant documents for any query.

Enhanced relevancy ranking

Bringing forward relevant results for any given search is critical for efficient discovery...

Using the product

For further assistance: