The problem with the cheap Walmart insulin is that this isn’t the current insulin that doctors prescribe to diabetics, it’s an older formula of insulin that was replaced with the current versions that came out 3 decades ago. Although it’s better than nothing, it’s metabolized much more slowly than the current fast-acting insulin, so that it’s much harder to keep your blood glucose from spiking really high after a meal.
It should only be used as a stopgap when people are otherwise unable to obtain the correct insulin. Though that itself is a thing that should never have to happen, and doesn’t in the rest of the modern world.
