When your cells take in creatine, they also pull in sodium, which makes the inside of the cell saltier. To balance that, water rushes in, making the cell swell up a bit.

Your muscles use a special door called SLC6A8 to let creatine in, and this door only works when there’s more sodium outside the cell than inside — like a pump that needs salt to open.

Cells use a special pump to create a sodium imbalance outside and inside the cell, and that imbalance acts like a battery to help pull creatine into the cell through a specific door called SLC6A8.

Taking creatine helps your muscle cells soak up more water, making them swell a bit—and this swelling tells your body to stop breaking down muscle as much.

When scientists lowered the sodium levels around rat muscle cells, the cells absorbed much less creatine—showing that sodium is needed for creatine to get inside these muscle cells.

When insulin is present, it tells muscle cells to pump more sodium and potassium around, which creates a better environment for the cell to pull in more creatine — a compound that helps muscles store energy.