The side effects of soaking in Epsom salts (magnesium sulfate) include confusion, dizziness or light-headedness, irregular heartbeat and lowered blood pressure, according to Drugs.com. Muscle weakness, skin irritation or infection, and sleepiness may occur as well.
Some of the side effects soaking in Epsom salts causes don't need medical attention, and some of these effects may disappear with time and use, advises Drugs.com. If symptoms persist, it is important to consult a physician. Overuse of Epsom salts is potentially life-threatening as it causes a slowing of the heartbeat and depression of the central nervous system; however, people who follow the usage instructions generally tolerate Epsom salts well. The many benefits of Epsom salts for the nervous system and muscles, as well as for prenatal care, outweigh the side effects.