Saffron contains many active compounds, but crocin, crocetin, safranol, and picrocrocin are considered to be the most important.[1] Following consumption, some of these compounds are transformed within the gastrointestinal tract, and the main compound found in the blood seems to be crocetin (although more research is needed in this department).[2]
Preclinical research suggests that saffron can influence the brain in a variety of ways, which likely explains its effects on mood and cognition. Saffron may prevent the reuptake of certain neurotransmitters — like dopamine, serotonin, and norepinephrine — which allows their effects to persist for longer.[3] Saffron may also interact with the HPA axis, leading to reduced levels of cortisol, and might influence neuroplasticity by increasing brain-derived neurotrophic factor (BDNF).[4]
As an antioxidant, saffron may increase the expression of nuclear factor erythroid 2–related factor 2 (Nrf2), leading to increased levels of antioxidant enzymes and an overall improved antioxidant capacity.[5][6] In animal studies, saffron has reduced oxidative stress in brain tissue.[7]