Rosemary (Rosmarinus officinalis) has garnered scientific interest for its potential to support mitochondrial function, primarily due to its rich content of polyphenols such as carnosic acid, rosmarinic acid, and essential oils. Preclinical studies suggest that these compounds exhibit antioxidant properties, which may help protect mitochondria from oxidative stress—a key factor in mitochondrial dysfunction and aging. For example, in vitro and animal research has shown that rosemary extract can modulate mitochondrial dynamics, enhance mitochondrial biogenesis, and reduce mitochondrial oxidative damage.

Additionally, rosemary's polyphenols have demonstrated the ability to modulate cellular signaling pathways (such as Nrf2 and PGC-1α) that play a role in mitochondrial health and energy metabolism. However, most of these findings are from laboratory or animal studies, and there is a lack of high-quality human clinical trials directly linking rosemary supplementation to improved mitochondrial function or related clinical outcomes. While traditional herbal medicine often uses rosemary for general vitality and cognitive support, its specific role in mitochondrial health is a relatively new area of research.

In summary, there is some emerging scientific evidence—mainly from preclinical studies—that rosemary and its constituents may support mitochondrial health, but robust human evidence is currently limited. Thus, the evidence rating is moderate to low.