Does Shampoo Expire? Here’s What to Know

Nothing lasts forever, as they say. But what about your personal care products? Does shampoo expire?

The short answer is yes. And while expired shampoo likely won’t cause hair loss, understanding the shelf life of your shampoo and conditioner is important for maintaining both the effectiveness of your hair care products and the health of your scalp and hair.

In this guide, we’ll explore how long shampoo lasts and the factors that determine when shampoos and conditioners expire. We’ll also examine why unopened shampoo can last longer than opened bottles.

Yes, shampoo expires, but it doesn’t necessarily have an expiration date printed on the bottle. Instead, it has what’s called a “shelf life” or “period after opening” (PAO) date.

Every bottle of shampoo, conditioner, or other hair care product has a shelf life, which varies depending on the formulation and whether it contains preservatives. If you look at your bottle of shampoo, you’ll likely see a small symbol that looks like an open jar with a number and the letter M printed inside. This is the PAO label, and it indicates how long the shampoo stays good after you open the bottle. The M stands for months, so if the label says 12M, that means the shampoo is good to use for a year after you open the bottle.

POA dates on shampoo generally range from about six months to two years.

Bottles that are open tend to degrade faster than unopened products. Unopened, a bottle of shampoo may have a shelf life of about two to three years, according to most experts who have been quoted on the topic.

Cosmetic products like shampoo are subject to expiration for many reasons. According to the FDA, these reasons include:

• Contact with your hands: Your fingers contain microorganisms such as bacteria and yeast that can overgrow in cosmetics.

• Reduced preservative efficiency: Preservatives inhibit the growth of bacteria and yeast. Over time, preservatives can become less effective at controlling these microorganisms.

• Exposure to moisture: Moisture trapped in the container can encourage the growth of microorganisms.

• Separation: Over time, the ingredients in a shampoo can separate, which may reduce their effectiveness.

• Exposure to sunlight, air, and temperature changes: These can all cause changes to the product’s color, texture, and smell.

Using expired shampoo is unlikely to cause serious harm. Over time, expired products can lose their effectiveness and might encourage the growth of yeast or bacteria that may irritate your skin. It’s possible that serious bacterial or yeast infections could develop in rare cases, but this hasn’t been reported in medical literature.

Some of the side effects of using expired shampoo may include:

• Scalp irritation: Shampoos designed to hydrate your scalp or help control dandruff might cause skin reactions like itching, redness, or rashes if they lose their effectiveness. 

• Dandruff: Likewise, as these shampoos break down, the shampoo may no longer effectively combat dandruff.

• Ineffective lather: Expired shampoo may not lather as well as it used to, leading to a less effective cleansing experience.

Does Expired Shampoo Cause Hair Loss?

No evidence exists to suggest that using expired shampoo causes hair loss.

Hair loss is medically known as alopecia. Common causes of alopecia include:

• Male or female pattern baldness

• Alopecia areata, an autoimmune disease

• Telogen effluvium, often caused by stress, malnutrition, or chronic illness

If you’re noticing hair loss, consider talking to a health care provider about the possible causes and your options for treatment. Hims can connect you with a provider via telemedicine.

Your shampoo should have a shelf life stamped on the bottle or written on the label, but this date may become unreadable over time.

If you aren’t sure whether your shampoo has expired, here’s how you can check for signs:

• Smell: Expired shampoo may have a sour, rancid, or off-putting smell due to the degradation of oils and preservatives. If it smells strange or unpleasant, it’s time to throw it away.

• Texture: Shampoo that has gone bad may become thick, clumpy, or watery. Lathering may also be less effective. You may not feel like the shampoo is doing its job.

• Color: If the color of your shampoo has changed, especially if it has gone from clear to cloudy or discolored, it may have expired.

• Packaging: Look for signs of bulging or leaking. If the bottle is compromised, bacteria or fungi may have contaminated the product.

If your shampoo exhibits any of these signs, it’s best to replace it with a new bottle of shampoo.

To ensure your shampoo and conditioner last as long as possible, you can follow these tips:

• Store your shampoo in a cool, dry place. Avoid storing shampoo and conditioner in places with high heat or humidity, such as in the shower or near a window. Direct sunlight can also potentially break down the active ingredients or the container itself.

• Keep the cap tightly closed. After each use, make sure the cap is securely closed to prevent air from getting in and breaking down the preservatives.

• Use the product regularly: The longer a shampoo sits on your shelf, the more likely it is to lose its effectiveness. If you have several bottles of shampoo, rotate them regularly to ensure that none go unused for too long.

So, how long does shampoo last? It depends on factors such as the product’s formula and how it’s stored, but most shampoos last about two to three years unopened and between six and 24 months once you’ve popped the bottle.

Check the POA date on the product’s label, and look for signs the shampoo is past its prime, such as separation or changes to its color, texture, or smell. If you experience scalp irritation or notice your shampoo isn’t working well, it may be time to toss the bottle and get a new one.

To help your shampoo last as long as possible, store it in a dry, cool, dark place.