Bests & Worsts Reviews from Amazon

This product is essentially Magnesium Chloride Hexahydrate [MgCl2(H2O)6] - the most common hydrated crystalline form of Magnesium Chloride. That makes it approximately 12% by weight magnesium. It is the magnesium in an easily absorbable form that provides the bennefit from this product. Magnesium Chloride is remarkable soluble in water. At high concentrations it feels almost oily or slippery which is why it is called "Oil of Magnesium" in this form though, there is nothing but water and magnesium chloride. The bag contains eight pounds of snow white flakes about the size of "Kellogs Corn flakes". I cannot speak as to the purity of the product, but my impression is that since it is apparently processed by re-crystallization (sort of like table salt is processed) it is probably fairly pure. This product is not labeled for consumption or oral usage as far as I can tell. I make a strong solution of Magnesium Chloride by weighing out 700 grams (1 1/2 pounds) of the flakes in a 1 liter (1 quart US) container. This amount fills the the container by volume when dry. Then I pour in distilled water to fill the container to the 1 liter (1 US quart, 32 US fluid ounces) capacity with the water and calcium chloride flakes. Then stir and let it sit to fully disolve. This concentration happens to equal to 420 mg of magnesium (US RDA for senior men) per 5 ml (one US teaspoon). However, remember that this product is NOT labeled or certified for oral use - this is just a reference as to the strength of this particular solution. Let the solution sit about an hour to be fully dissolved. Then I strain the solution through a clean, fresh coffee filter to remove whatever hasn't dissolved. Then I heat the strained solution in a Pyrex container in the microwave until it just begins to boil. The purpose is to kill any microorganisms that might be present. I then rinse my glass or plastic bottles (and funnel) to be used for storage (after they have been thoroughly washed) in ordinary 3% hydrogen peroxide solution. Drain, but do not dry the inside (the peroxide kills microorganisms that might be present in the container). Once the solution has cooled enough to safely pour into the storage bottles you are done. You now have your own mix of "oil of magnesium" considerably cheaper than buying it pre-mixed. If you don't feel like doing all the steps to be sure you don't have any microorganisms or contaminants in your mix, then buy the already made solution. The primary reason to use the concentrated Magnesium Chloride solution on your skin as opposed to in a bath is for economy. Assuming it takes two to four times the oral RDA equivalent applied to your skin (2 to 4 teaspoons) per day, the cost is around 8 to 16 cents per day at Amazon's current price for the 8 pound bag. If you use the magnesium chloride flakes in your bath you will need to use at least 1/4 pounds at a cost of $1.35 per day. While this might feel good from time to time, using the concentrated solution is much more economical! About the product itself: The Good: Product appears to be of good and uniform purity Reasonable cost per pound for what you get. Bag is sturdy, well sealed, and recloseable with an internal zipper type seal. Area for Improvement: It would be great if the supplier provided some indication of the purity of the product.