Zinc plays a crucial role in many biological processes, including immune function, enzyme activity, and hormone regulation. When it comes to the "Cortisol body system"—meaning the regulation of cortisol, a glucocorticoid hormone produced by the adrenal glands—there is some scientific evidence that zinc status can influence cortisol levels, but this evidence is relatively limited and not robust.

Several studies have shown that zinc deficiency can lead to increased production of cortisol, possibly due to its role in modulating the hypothalamic-pituitary-adrenal (HPA) axis. For example, animal studies indicate that zinc-deficient rats have higher baseline levels of corticosterone (the rodent equivalent of cortisol), suggesting an upregulated stress response. Some small human studies have found that zinc supplementation may blunt the rise in cortisol following acute stress, but these results are preliminary and not universally replicated.

Overall, while zinc is not a primary or direct regulator of cortisol, its role in general endocrine and immune health provides some rationale for its inclusion in supplements targeting stress or adrenal support. However, the evidence is not strong, and more human clinical trials are needed to establish a clear, causal connection between zinc supplementation and improved cortisol regulation in humans.