Eventually. You could try to strengthen it with a piece of strapping on edge screwed to the front bottom of the shelf. Or replace them with something more sturdy.
If it's MDF it'll get worse very quickly. Eventually it'll break or chip. If it's a real wood, it could last but will always hold a bow. Neither will ever look new again. Go to the hardware store and get some new boards.
LaChanz t1_j2ffm6f wrote
I have a bookshelf that does the same thing. What I can do is take all the books off and flip the shelves over. I do it every year or two.
But yes, it will.continue to get worse. That's the problem with the cheap materials they use.