Reviewed and Approved by Matilda Baghdasarian, Laboratory Services Associate Director
1-Minute Summary
- Health Canada’s NHP GMPs Version 4.0 takes effect March 4, 2026, replacing the 2015 guide.
- Every natural health product (NHP) must now have a completed stability study, written protocol, and stability report.
- Real-time stability studies are required to confirm expiry dates; accelerated or similar-product data alone aren’t enough.
- Companies can use bracketing and matrixing to streamline testing, but only if scientifically justified.
Health Canada Releases NHP GMPs Version 4.0
On Sept. 4, 2025, Health Canada released Version 4.0 of the Good Manufacturing Practices (GMP) Guide for Natural Health Products (GUI-0158).
This is the first major update since 2015 and becomes enforceable on March 4, 2026. Among the most important revisions are new, detailed requirements for stability testing (Section 52), which outline how companies must establish expiry dates, confirm shelf life, and maintain compliance.
These changes directly affect how you conduct stability testing for your natural health products. Below, we answer common questions to help your company maintain compliance with NHP GMPs Version 4.0.
How have NHP Stability Testing Requirements Changed in Version 4.0?
Under Version 3.0, stability testing expectations were less explicit. Version 4.0 introduces some specific requirements, such as the following:
- A completed stability study for every NHP marketed in Canada.
- A written stability protocol for each study.
- A stability report with results.
- Ongoing responsibility for up-to-date records, regardless of whether testing is performed by the manufacturer, importer, or another party.
What are Manufacturers’ and Importers’ Responsibilities?
Manufacturers and importers must establish written SOPs and practices for stability studies to ensure finished products meet approved specifications. They must:
- Conduct stability studies that align with Canadian requirements.
- Review and evaluate results regularly.
- Maintain complete stability reports.
- Perform any missing tests if relying on foreign data.
Importers cannot simply accept foreign studies — they must ensure protocols meet Canadian standards and fill any gaps before release to market.
What Must a Stability Program SOP Include?
A written SOP is now mandatory and should cover:
- Manufacturer-assigned initial expiry dates.
- Conducting real-time stability studies.
- Collecting additional stability data when needed.
- Designing stability protocols.
- Maintaining stability reports.
Version 4.0 also permits “bracketing” and “matrixing” to reduce the number of studies for products with multiple package types, referencing ICH Q1D as a useful model.
What are “Bracketing” and “Matrixing”?
Bracketing and matrixing are study designs that reduce the number of stability studies needed when products come in multiple package types, sizes, or strengths.
- Bracketing means testing only the “extremes.” For example, if an NHP is sold in 30-count, 60-count, and 120-count bottles, you may study only the smallest and largest sizes, assuming the middle size behaves similarly.
- Matrixing involves testing a selected subset of all possible combinations of product variants (e.g., different flavors, sizes, or packaging types) on a rotating basis, with the expectation that untested combinations will follow the same stability trends.
Health Canada’s NHP GMPs Version 4.0 allows these approaches, referencing ICH Q1D for guidance. However, they must be scientifically justified — companies must show that the variants not directly tested are comparable in ways that affect stability (formulation, packaging material, process). These designs can save time and resources while still providing valid stability data for all marketed products.
How Should Initial Expiry Dates be Determined?
Every finished NHP sold in Canada must carry a lot number and expiry date. Initial expiry can be assigned using:
- Results from accelerated or real-time studies.
- Data from similar products in comparable packaging.
However, accelerated testing alone is often unreliable for products sensitive to heat or humidity. Real-time studies are required to confirm shelf life. When using similar product data, companies must maintain evidence of comparable formulation, packaging, and processes to justify the approach.
What are the Requirements for Real-Time Stability Studies?
Real-time studies verify shelf life and ensure each finished product meets label claims until expiry. Requirements include:
- Lots tested must use the same formulation, packaging, and manufacturing process as marketed products.
- Studies should include worst-case scenarios, such as bulk product held before packaging.
- Expiry dates must be assigned by the manufacturer from the date of manufacture, not packaging.
Stability chambers or dedicated rooms must be used, with controlled temperature, humidity, and light. Records of conditions must be maintained.
Can Expiry Dates be Adjusted After Initial Assignment?
Yes. Real-time studies may support extending expiry dates if data show stability beyond the initial period. Additional stability data can also help with complaint investigations, storage condition improvements, or hold-time justifications.
Any changes must be documented in stability protocols and supported by scientific evidence. Out-of-specification (OOS) or out-of-trend (OOT) results must be investigated, and expiry dates adjusted or shortened if needed.
Can Certified Laboratories Conduct Our NHP Stability Testing?
In-package stability testing for natural health products under Health Canada NHP GMPs Version 4.0 requires more planning, documentation, and evidence than before.
Certified Laboratories, with locations in Canada and the U.S., offers stability testing programs aligned with Health Canada, ICH, FDA, USP, EP, and ISO standards. Our services include…
- Long-term, intermediate, and accelerated studies (Zones II & IVa, refrigerated, frozen).
- Expert guidance in designing compliant stability protocols.
- Broad analytical chemistry and microbiology assays.
- Stability reports with trending data and representative images of pulled samples.
Contact us today to prepare your products for the March 2026 deadline and ensure your stability program meets the new GMP expectations.
