Clinical Trials: Non-Investigational Medicinal Products in the UK

1. Legal Status and Scope

This guidance supports sponsors and investigators in understanding the regulatory requirements for non-investigational medicinal products (NIMPs) under the Medicines for Human Use (Clinical Trials) Regulations, as amended by forthcoming amendments that will come into force on 28 April 2026. Until then, the guidance is in draft for preparation purposes.
Source: Clinical trials: non-investigational medicinal products - GOV.UK

2. Definitions

Under the Clinical Trials Regulations, a non-investigational medicinal product (NIMP) is defined as a medicinal product used or to be used in a clinical trial but not as an investigational medicinal product (IMP) as described in the trial protocol.
This guidance also generally applies to non-medicinal products that are used similarly in a trial (e.g., use of pollen or house dust in a skin prick test).
Source: Clinical trials: non-investigational medicinal products - GOV.UK

3. Using Non-Investigational Medicinal Products

3.1 Authorisation

In most cases, NIMPs used in a clinical trial should hold a marketing authorisation.
Where an authorised product is unavailable or cannot reasonably be used, the sponsor may use an unauthorised NIMP, provided that clear justification is given in the trial protocol. Acceptable reasons include lack of availability (excluding price issues) or preparation according to an official or magistral formula.
Source: Clinical trials: non-investigational medicinal products - GOV.UK

3.2 Examples of NIMPs

Common NIMPs include:

• Rescue medications to manage adverse reactions or lack of efficacy of the IMP.
• Challenge agents used to produce a physiological response required to assess the IMP.
• Products used to assess endpoints, such as radiopharmaceuticals for imaging.
• Background treatments given as standard care to all participants.
  Source: Clinical trials: non-investigational medicinal products - GOV.UK

4. Documentation Requirements

NIMPs must be included in the clinical trial application dossier:

• The application should provide details of the quality of each NIMP.
• A list of proposed NIMPs should be included in the cover letter.
  For authorised and unmodified NIMPs, a simplified quality dossier may be acceptable.
  Non-medicinal products should be listed with pertinent safety and property information.
  Source: Clinical trials: non-investigational medicinal products - GOV.UK

5. Manufacture

Under regulation 45A of the Clinical Trials Regulations, all NIMPs—whether authorised or not—must be manufactured or assembled in accordance with Good Manufacturing Practice (GMP) principles and guidelines, similar to investigational products.
Non-medicinal products must meet safety standards appropriate to their intended use.
Source: UK legislation on clinical trials and GMP requirements

6. Labelling of Non-Investigational Medicinal Products

Regulation 46A requires that NIMPs are subject to the same labelling requirements as IMPs. Because most NIMPs are authorised products used unmodified, labelling is typically consistent with UK prescribed medicine requirements.
The label should include the clinical trial identification and other required information to support participant safety and compliance.
Source: Clinical trials for medicines: labelling - GOV.UK

7. Safety Reporting

Safety reporting for NIMPs should follow the same principles used for IMPs. Sponsors must include serious adverse events or reactions suspected to be related to a NIMP in their safety reports and development safety update reports as appropriate.
Source: Clinical trials: non-investigational medicinal products - GOV.UK

8. Summary

In summary, NIMPs are medicinal products used in a clinical trial but not evaluated as the investigational product itself. Sponsors must ensure that:

• NIMPs are authorised or justified if unauthorised,
• Included correctly in regulatory documentation,
• Manufactured to GMP standards,
• Labelled appropriately, and
• Adequately included in safety reporting to comply with UK clinical trial regulations.
  This ensures regulatory compliance and participant safety under the current regime.
  Source: Clinical trials: non-investigational medicinal products - GOV.UK