Most of us have faced the pesky shower pet peeve of running out of shampoo when at least half a bottle remains of its corresponding conditioner. When that happens, bathroom cabinets and shower shelves can end up crowded with old conditioner bottles. These conditioners don't have to go to waste, but take heed of some shelf-life laws to avoid using an ineffective, expired product.

Rules to Go By

Lifestyle magazine "Real Simple" states that shampoos, conditioners and shower gels have a similar shelf life of approximately three years. Since many conditioners do not have expiration dates listed on their packaging, a handy guideline to follow is to keep an unopened bottle for no longer than three years and an opened one for no more than 18 months. To maximize your conditioner's longevity, avoid sticking your fingers in the bottle, which can cause contamination. Keep in mind that the rules change for natural and organic conditioners, which lack the preservatives of other products and therefore have a shorter lifespan.