Adding methylene blue doesn’t change how well heart cell power plants can hold onto calcium, meaning it doesn’t protect against the pore that can cause cell death under stress.

Adding a tiny amount of methylene blue to heart cell power plants makes them use oxygen more efficiently, no matter what fuel they're burning.

A tiny amount of methylene blue helps heart cells make energy better, but too much actually hurts them — it’s a classic case of 'less is more'.