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Supporting mechanistic modelling for survival

DEBtox Researc

Welcome to the openGUTS information pages

OpenGUTS is a user-friendly software to perform analyses with GUTS: the General Unified Threshold model for Survival. GUTS is the leading toxicokinetic-toxicodynamic framework for the endpoint survival (and other non-reversible all-or-nothing effects).

This site hosts the software itself, as a standalone Windows executable, with manuals and background documentation. Since openGUTS is (as the name implies) open source, also the source files can be obtained here. Additionally, you can download the Matlab version, which served as the blueprint for the standalone version. The Matlab version has basically the same functionality, and can be easily adapted or extended to perform customised analyses. Finally, we provide (links to) further information on openGUTS and GUTS.

The main features of the software are:
  1. Open and free: the software is open source and freely downloadable. The fully-functional Matlab version that served as the prototype is also available.
  2. User-friendly: fit models and derive confidence intervals without requiring user interaction (e.g., no need for starting values).
  3. Robust: always find the global optimum and relevant intervals, even for awkward data sets.
  4. Flexible: allow time-varying exposure, missing data, simultaneous fitting on multiple data sets, etc.
  5. Efficient: rapid screening of exposure profiles (e.g., FOCUS output) by batch processing.
  6. Supportive: the software follows the workflow as laid down in the 2018 EFSA opinion on TKTD models.

First real error found. The IT calculations use a shortcut that does not work in all cases. This error will affect IT calibrations for time varying exposure, where the exposure scenario includes episodes of linear decrease over time (for constant exposure and block pulses, it will be fine). It will also affect IT LPx predictions when the exposure scenario is specified with a crude resolution (the hourly resolution of FOCUS profiles will lead to negligible errors). This error is repaired in the update of the Matlab version, to v. 1.1. Download a PDF document explaining this error in detail. (posted 19 May 2019)

openGUTS standalone Windows executable

Screenshot prototype small
openGUTS in Matlab


  • 26 May 2020: update of the Matlab version of openGUTS. This version 1.1 repairs the error that was discovered (the standalone still has this error, so do take a look at the dedicated document for this error). See download page.
  • 20 May 2020: document explaining the error linked to the error warning (on this page above, and on the downloads page). Also updated the 'list of known issues' with this error, and a few more small GUI bugs.
  • 20 May 2020: openGUTS on-line, completely-DIY, short course is now available. See course page.
  • 19 May 2020: error found in the IT calculations. More information and workarounds/repairs coming soon.
  • 10 May 2020: small update to the interpretation document, adding a section with a brief description of the model and its parameters (and what they do). Furthermore some small textual changes and error repair.
  • 21 April 2020: updated the "list with known issues" with a few small bugs and additional items for the wishlist. See download page.
  • We will provide a half-day short course on the openGUTS software at the virtual SETAC Europe in May 2020. See the SETAC web page, and scroll down to "TC11 - Introduction to Effect Modelling with the User-Friendly Software OpenGUTS." We need to see how SETAC will support the short courses on-line, so more information will follow. There will also be a poster on openGUTS at this conference (ID 4.07P.4).
  • 12 December 2019: added the source code and an updated version of the design document. See download page.
  • 10 December 2019: version 1.0 of the standalone is available for download (with manual, but not yet with the source code). Furthermore, a new version of the Matlab version (previously known as the prototype). Also updates of the manuals and for several of the background documents. See download page.
  • 4 November 2019: update for the openGUTS prototype in Matlab, and small update to its manual and design doc. See download page.
  • 18 Sept. 2019: the planned course on openGUTS in October 2019 has been cancelled. Unfortunately, we had insufficient registrations.
  • 30 Aug. 2019: small update to the design and interpretation documents on the download page.
  • 22 July 2019: update of the test document (includes ring test but also additional data sets with difficult properties). See download page.
  • 12 July 2019: another update of the prototype, solving a few minor bugs and adding some nice features (wait bars and error boxes). See download page.
  • 23 May 2019: tiny update of the prototype. It now includes the same set of exposure profiles as used in the EFSA scientific opinion. See download page.
  • 22 May 2019: added a walkthrough through the code of the prototype (made with Matlab's publish option).
  • 21 May 2019: a number of background documents are already downloadable.
  • 17 May 2019: first release of the openGUTS prototype in Matlab. See download page.
  • 14 May 2019: the website is online! Not all pages are completely filled at this point ....

The openGUTS project, This site is maintained by Tjalling Jager, email: tjalling (at)