Magnesium sulfate decomposes into magnesium oxide (MgO) and sulfur trioxide (SO). The heptahydrate can be prepared by neutralizing sulfuric acid with magnesium carbonate or oxide, but it is usually obtained directly from natural sources. It is on the WHO Model List of Essential Medicines, the most important medications needed in a basic health system. Magnesium sulfate is a common mineral pharmaceutical preparation of magnesium, commonly known as Epsom salt, used both externally and internally. Magnesium sulfate is highly water-soluble and solubility is inhibited with lipids typically used in lotions. Lotions often employ the use of emulsions or suspensions to include both oil
U Should've Known Better song entered the "Billboard" Hot 100 chart, where it debuted at number 67 in the week of June 6, 2004, the second-highest debut of the week. "U Should've Known Better" remained twenty weeks on the chart, reaching its peak position of number 19 in its ninth week. It marked the second single from "After the Storm" to reach the top twenty on the Hot 100chart and, as the album's final single, would remain its second highest-charting offering behind leading single "So Gone." Although never released on a CD single or CD maxi single format, "U Should've Known Better" was also