Woman rinsing shampoo suds from her hair in the shower.

, hair needs a lot of attention – so much so that own up to 10 haircare products. The thing is, many of them end up sitting in your bathroom cabinet for what feels like eons, which begs the question: Does shampoo expire? The short answer is yes, it has a lifespan.

Just as spoiled food can upset your stomach, out-of-date beauty products like shampoos can irritate your scalp and hair. Check for these signs to know whether it’s time to throw yours away.

It Has a Weird Texture

Regular shampoos have a thick texture akin to syrup. The rich consistency comes from a blend of ingredients, including surfactants, thickeners, and conditioning agents. These chemicals break down and lose their original integrity over time, causing your shampoo to clump and curdle.

Another visual cue that it’s past your shampoo expiration date is the separation of its ingredients. When the stabilizers in the shampoo have gone bad, you’ll see particles floating or settling at the bottom. Shaking it won’t make any difference, either.

It Smells Musty

Some shampoos have fragrance while others don’t. Regardless, no shampoos should smell like a wet towel. If yours does, it might be a sign of bacterial growth or expired . Factors such as prolonged exposure to moisture and changes in temperature can also trigger chemical reactions, which lead to this off-putting odor. That’s reason enough to shut the lid after every use unless you want your shampoo to turn rancid. 

Its Color Has Changed

One unmistakable evidence that answers the “Does shampoo expire?” debate is its change in color. The reason behind this is the oxidation of the dyes or pigments. Even clarifying shampoos without added hues can turn cloudy due to mold stains around the neck of the bottle.

To extend the shelf life of your haircare products, make sure to scrub the accumulated gunk on the cap with an old toothbrush. Since mold thrives in damp environments, store your products in a cool, dry place away from direct sunlight. Wiping down the bottles after each shower might help, too.

You’ve Had It for More Than a Year

If you’re wondering how to check for a shampoo's expiry date, look at the bottom of the bottle. That said, not all brands print this information, simply because they’re not required to by law. The alternative is to visit their website for the estimated storage duration. Generally, most shampoos can last for around 24 to 36 months from the date of manufacturing in sealed packaging.

Does shampoo expire if you rarely use it? Sadly, yes. Once you’ve opened the bottle, its lifespan declines rapidly. But even without a written expiry date, you can tell when to toss your shampoo by locating the period after opening (PAO) mark at the back. This symbol usually displays an open jar icon with a number followed by the letter “M.” For example, “6M” means the product is okay to use for six months after opening.

Your Scalp Feels Tingly After Shampooing

Few people remember the exact date they purchased their shampoo, let alone when they first opened it. So, there’s a chance you’ve been using an expired shampoo without knowing.

and are the most common expired shampoo side effects. Those who have skin conditions like and dermatitis might also get flare-ups. If you experience these symptoms post-shampooing, you’re better off investing in a new product.

For people who have , treat your locks with TRESemmé Pro-Color Series Blonde Brilliance Shampoo. This purple shampoo features Anti-Fade technology to neutralize brassy hues and helps keep your dyed hair vibrant for longer. Don’t miss out on TRESemmé Pro-Color Series Blonde Brilliance Conditioner, too. It’s formulated with violet pigments to preserve your hair color as well as jojoba oil to nourish each strand and boost shine.

Take this as a sign to declutter your . Don’t wait until your scalp and hair suffer from spoiled products. And the next time somebody asks, “Does shampoo expire?” show them this article.