Good Health Magnesium Sustained Release provides slow release marine magnesium to help support stress, tension and relaxation through the day. Magnesium Sustained Release is a unique product, specifically designed to slowly release magnesium in your body over 8 hours, allowing your body to properly absorb and utilise magnesium as it needs it, without any negative digestive effects. Magnesium Sustained Release is a high strength magnesium formula that is made from Aquamin Mg. Aquamin Mg is marine sourced magnesium, derived from seawater and so it naturally contains many other trace minerals too. This natural marine form makes it easily utilised in the body.