They definitely can go bad, the more natural products go bad quicker because they lack preservatives. I had a huge bottle of natures gate shampoo, I don't shampoo frequently so it eventually got really cloudy and weird looking. I make sure not to buy too much shampoo because it takes me forever to go through a bottle.
I saw some giovanni products on clearance in clear bottles that had turned pink :-|
But some products can last a long time and I think dominican products keep really well because they're far from all natural. Baba de caracol has had a new formula out for about a year, but I kept hitting up the one store I knew had the old version on the shelves and it still works great. I will keep buying it whenever I see it!
