Has a lot to do with rate you use up mag too. If there's not enough to go around, you wont notice the fibro benefits. Since it can take months to restore your levels via oral mag, using mag oil in addition to mag malate could be extremely beneficial.
It's not that it's not absorbable. Mag malate is a far superior choice than the mag oxide sold at the drugstore. Just that arent seeing the benefits yet. http://drcarolyndean.com/2012/10/whe...akes-me-worse/
Be sure to check your serving size too. One bottle of mine requires 6 tablets to equal around 400mg and my current bottle requires 3 tablets. Sneaky labeling.