Skip to content
Skip to navigation menu


Substantial and Non Substantial Amendments

Substantial Amendments

Amendments are alterations made to a study after a favourable ethical opinion has been given. A substantial amendment is defined as an amendment to the terms of the Research Ethics Committee (REC) application, or to the protocol or any other supporting documentation, that is likely to affect to a significant degree the:

  • Safety or physical or mental integrity of the subjects of the study
  • Scientific value of the study
  • Conduct or management of the study or
  • Quality or safety of any medicinal product used for clinical trials

Substantial amendments require a favourable opinion from the REC before they can be implemented.

The only exceptions to this are:

All other substantial amendments should be notified to the REC that gave a favourable opinion using a notice of substantial amendment form, which can be downloaded from the NRES Website.

The co-ordinator of the main REC will write confirming whether or not the notice of amendment is valid for review, normally within five working days of receipt. The REC will issue an ethical opinion on the amendment within a maximum of 35 days from the date of receipt of a valid notice of amendment.

Where an unfavourable opinion is given, the applicant may submit a modified amendment. The REC will give an opinion on a modified amendment within 14 days of receipt.

Non-substantial Amendments

Notices of substantial amendment should only be used to notify substantial amendments. There is no requirement to notify the main REC of non-substantial amendments. Sponsors or chief investigators wishing to do so voluntarily should use a separate covering letter. The letter should make it clear that the amendment is not substantial and does not require an ethical opinion to be given. The main REC will acknowledge receipt.

Further information regarding substantial and non-substantial amendments is available on the NRES Website

Notify the Sponsor and Host Organisation

Researchers are also required to notify the Sponsor of any substantial or non substantial amendments. Please notify the Research Governance Team in RACD of any changes.

In addition all host organisations involved in the research study must be notified and approve any substantial or non substantial amendments, before the study can continue.

Please email/send study amendments to the Research Governance Team