Pyrroloquinoline quinone disodium salt (PQQ) is being investigated for its potential to support memory and brain function, and there is some scientific evidence, primarily from animal studies and limited human clinical trials. PQQ is a redox cofactor and antioxidant, and has been shown in preclinical studies to protect neurons from oxidative stress and to stimulate mitochondrial biogenesis, which is important for cellular energy and brain health.

A small randomized, double-blind, placebo-controlled trial in healthy elderly subjects (Nakano et al., 2012) found that supplementation with PQQ (20 mg/day for 12 weeks) resulted in improvement in measures of attention and memory compared to placebo. The mechanism is believed to involve PQQ’s ability to promote nerve growth factor synthesis and protect against neurotoxicity. However, the sample size was small and the study duration short. A combination study of PQQ and CoQ10 showed improvements in cognitive measures, but it is not clear if the effects were due to PQQ alone.

Overall, while there is some preliminary evidence supporting PQQ’s use for brain health, the number and quality of human studies are limited, and larger, longer-term trials are needed to confirm efficacy. Thus, the evidence rating for this use is modest.