A sample of 36 fish oil supplements sold in New Zealand was tested for freshness, and most showed signs of oxidation, meaning they had degraded beyond accepted quality standards.

We analyzed one assertion about fish oil supplements in New Zealand, and the evidence we’ve reviewed suggests that most of the supplements tested showed signs of oxidation, meaning they had degraded beyond accepted quality standards [1]. This was based on a sample of 36 fish oil products sold in the country. Oxidation happens when oils break down due to exposure to air, light, or heat, which can reduce their effectiveness and potentially create harmful compounds. While we don’t know the exact number of supplements that met freshness standards, the available data indicates that the majority did not. We have no evidence to suggest that most products in New Zealand meet oxidative stability benchmarks. What we’ve found so far points to a widespread issue with product freshness, but we cannot say how many, if any, supplements passed quality tests. The evidence we’ve reviewed leans toward the idea that consumers may be purchasing fish oil supplements that are no longer fresh. Until more testing is done across a broader range of brands and batches, we can’t determine how common this problem is or whether it’s improving. For now, if you’re taking fish oil in New Zealand, it may be worth checking for third-party certifications or storage instructions that help preserve freshness.