In people

On its own, under the skin, a small volume of plain water stings a little more than salted water does, because your nerve endings read the weak tone. That sting fades in seconds as tissue fluid dilutes it. Once a powder is dissolved in it, the mixture carries that solute and feels like any other small injection. What people notice is the mixing itself: a cake that clears in under a minute with a gentle swirl, a liquid that stays glass clear, and a dose that behaves the same on day one and day five.