Did you know??? truth always in front of you…. now what’s in your food

In Logan, there are no more mutants being born. The X gene that lay dormant in humans, able to be passed from parent to offspring causing them to become mutants, has effectively been blocked and suppressed by decades of exposure to genetically modified corn and corn syrup that was specifically created to do just that. Literally millions of gallons of this mutant gene suppressing GMO sludge was sold to, and consumed by, the unsuspecting population. This not only caused the mutant birthrate to drop to 0%, but it also affected the existing mutants by causing them to slowly lose their mutant abilities.

This is the real reason Wolverine’s healing factor has slowed down in Logan, not old age. Wolverine has always had adamantium poisoning, it’s a side effect of a foreign metal being grafted to his bone structure. His genetic mutation is what kept the detrimental effects of the poisoning from seriously hampering him. Now that Logan is basically being sustained by power suppressing GMO’s, his healing factor is working quadruple overtime just to compensate for the constant high level toxicity of the adamantium on his bone, making any other wound he receives take that much longer to heal.

The negative effect the GMO’s have on his body is also shown when he tries unsheathing his claws and one of them gets stuck. His bone claws are a part of his mutation as well as his healing factor, and since he is losing his powers, his claws aren't working properly either.

By the end of the movie, his healing factor can't keep up with the trauma his body is experiencing, and after he overdoses on a substance that amps mutant powers considerably, his healing factor burns out as a side effect, compounded by all the abuse Logan has taken.