Its no supplment. You can take a cup of Epsom Salt and pour in bath tub to absorb magnesium or "nigari Oil' (mg chloride) which you apply the oil on skin for better absorption. I was one of them who does not get good benefits from oral magneisum. It wasnt till I started doing detox baths and using nigar oil.
Go to the magnesium chloride forum and read success posts. but I feel you know your body and what it needs. I wish you the best finding what works.