Earlier quoted context omitted.
The specialized device for cutting pills costs about $3 and is available at every single pharmacy on earth. They are generally designed to be used by the elderly and infirm.
How small of a pill can they accurately cut? The caffeine pills I got off Amazon are about the size of 2 pinheads and are kind of soft. I don't think they would be easy but I've never used a pill cutter.
They are fairly ingenious for how simple they are, basically you put the pill in a V-shaped compartment so it would settle down to the base of the V. Flip the lid over and a razor blade would apply even pressure and split any size pill perfectly in half.
Some were more amenable than others to the splitting, while some would explode into a chalky mess, but I think that had more to do with the filler than the ingredients, which gives the opportunity to shop around.