Magnesium lotion can have many benefits, including:
Muscle health
Magnesium lotion can help with muscle aches and soreness, especially after exercising. It can also help prevent muscle cramping and fatigue. 
Skin health
Magnesium lotion can moisturize and hydrate skin, and help with redness and sensitivity. It can also help with acne and rosacea. 
Sleep
Magnesium lotion can help you fall asleep and sleep soundly. It can help with sleep disturbances like restless legs syndrome and nocturnal leg cramps. 
Stress relief
Magnesium lotion can help ease stress and tension. It can also help calm nerves and muscles. 
Joint pain
Magnesium lotion can help reduce inflammation, which may help with certain kinds of arthritis. 
Overall health
Magnesium lotion can help support heart health, bone health, and nervous system health. It can also help regulate blood sugar and blood pressure. 
Collagen regeneration
Magnesium lotion can help support collagen regeneration.