The role magnesium plays in supporting optimal sleep is not fully understood. One possible explanation is that magnesium is a stimulator of GABA, a naturally occurring amino acid that works as a neurotransmitter. GABA is known to decrease activity in the nervous system, which can lead to relaxation. Some studies show that adequate magnesium status (from either food or supplementation) may help with sleep quality and duration. While there is some evidence that magnesium supplements specifically may help with sleep, more research is needed.