If you only shampoo once a week or rotate between multiple hair products, it’s easy for a bottle of shampoo or conditioner to sit in your shower for months, even years. While that can feel economical, it raises an important (and often overlooked) question: Do shampoo and conditioner expire?
The short answer is yes and using them past their prime isn’t a great idea. Ahead, everything you need to know about shampoo and conditioner expiration, including how long they last and the signs it’s time to throw them out.
Do Shampoo and Conditioner Expire?
Yes, both shampoo and conditioner expire. Most products come with either an expiration date or a PAO (Period After Opening) symbol printed on the bottle or outer packaging. The PAO icon looks like a small open jar with a number followed by an “M,” such as 6M, 12M, 18M, or 24M, which indicates how many months the product is safe to use after opening, provided it’s stored properly.
If you can’t find this information, reaching out to the brand or manufacturer is your best bet. If they’re unable to confirm the product’s age or batch details, it’s safer to discard it.
How Long Do Shampoo and Conditioner Last?
While formulas vary, general guidelines apply:
- Opened bottles: typically last 6 months to 1 year
- Unopened bottles: can last 2 to 3 years
Once opened, exposure to air, water, and bacteria can compromise the formula over time—even if the product still looks fine at first glance.
What Happens If You Use Expired Shampoo or Conditioner?
Expired shampoo and conditioner can become chemically unstable. When preservatives break down, ingredients may separate, lose effectiveness, or become contaminated with bacteria or mold.
Using expired products can lead to:
- Scalp irritation or dryness
- Itching, peeling, or redness
- Damage to hair follicles
- In rare cases, contact dermatitis (an itchy or swollen rash)
Because hair and scalp products absorb quickly, even brief exposure to unstable formulas can cause unwanted side effects.
Signs Your Shampoo or Conditioner Has Expired
If you’re unsure whether a product is still safe to use, look for these red flags:
1. Separation or Layering
If oils and water separate into visible layers, the formula has likely destabilized.
2. Texture Changes
Clumpiness, unusual thickness, or thinning are signs the preservatives are no longer effective.
3. Color Changes
Discoloration or an unexpected tint suggests the ingredients have broken down.
4. Off or Unusual Smell
A sour, musty, or “off” odor can indicate bacterial growth or mold.
Pro tip: Don’t try to “fix” expired products by shaking the bottle. Once a formula has separated, it won’t perform or absorb the way it was intended to.
The Bottom Line
Shampoo and conditioner don’t last forever. Once expired, they may be ineffective at best and harmful at worst. To avoid irritation or damage, always check the PAO symbol or expiration date, store products in cool, dry conditions, and aim to finish them within the recommended time frame.
When in doubt, it’s better to toss the bottle than risk your scalp health.
Comments are closed.