Your body needs magnesium to function properly, and a lack of this mineral can lead to muscle weakness, irregular heartbeat and irritability, according to the National Institutes of Health Office of Dietary Supplements. You can usually get enough via your diet by eating green leafy vegetables, whole grains, peas and nuts. However, you can also take a magnesium supplement. Magnesium chloride is an inorganic supplement, in contrast to magnesium gluconate or malate, which are organic forms of magnesium, according to the "Handbook of Minerals as Nutritional Supplements" by Robert A. DiSilvestro. Magnesium chloride will raise magnesium levels in your body. You may, however, experience some side effects.
You may experience diarrhea with magnesium chloride supplements, which usually come in the form of sustained-release tablets, according to Drugs.com. This is a common side effect. You should check with your doctor if it persists.
You need to seek medical attention immediately if you suffer an allergic reaction while taking magnesium chloride supplements. Symptoms may include difficulty breathing; a tight feeling in the chest; a rash; hives; itching; or a swollen face, tongue, lips or mouth, according to Drugs.com.
If you notice slow reflexes or nausea due to taking magnesium chloride supplements, you need to gain medical attention, advises Drugs.com. Also seek attention if your heartbeat slows, you have double or blurred vision, or you become extremely drowsy. On the other hand, having too much magnesium in your body can affect your nervous system and cause your blood pressure and respiratory rate to fall. A coma, respiratory paralysis or even death can result from extremely high levels of magnesium chloride in your system. The tolerable upper limit intake for adults is 350 milligrams per day.
Magnesium can interact with several medications, so talk to your doctor before you start supplementing with it, advises the University of Maryland Medical Center. Be especially careful if you are taking antibiotics, blood pressure medicine, medicine to treat diabetes, digoxin, diuretics, hormone replacement therapy during menopause, levothyroxine, penicillamine or osteoporosis medication.