Benign fasiculations for 2 years. magnesium level 1.8, in range, but low. i want to try magnesium but what is best that won't cause diarrhea?

Magnesium glycinate: Magnesium oxide is the most commonly manufactured, due to its ease of manufacturing and low production cost--but it is not water soluble and can be poorly absorbed. Magnesium citrate pills have a high bioavailability, but the citric acid is a mild laxative. Magnesium glycinate is well-absorbed and reportedly the least likely to cause diarrhea. This one may be best option for correcting deficiency.

Glycinate or Taurate: Many with "normal" serum magnesium levels are still deficient so this is reasonable to try. I agree with Dr. Carr's fine answer recommending Mag. glycinate but another good option is Magnesium taurate. Epsom salt baths are also proven to raise magnesium levels. See http://drcarolyndean.com/magnesium_miracle/ for more on magnesium and health.