Yes, hair developer can go bad.
How Long Does Hair Developer Last?
The lifespan of hair developer depends on whether it is opened or unopened.
Unopened Hair Developer
- Shelf Life: An unopened bottle of hair developer will remain usable for approximately 3 years.
Opened Hair Developer
- Use Within: Once you open a bottle of hair developer, you should use it within 6 months to ensure optimal performance.
Factors Affecting Hair Developer Shelf Life
Several factors can affect how long your hair developer remains effective:
- Exposure to Air: Once opened, exposure to air will cause the developer to oxidize, diminishing its potency over time.
- Storage Conditions: Exposure to extreme temperatures or sunlight can cause the developer to degrade faster.
- Store unopened and opened bottles in a cool, dark place.
- Keep the bottle tightly closed.
Signs of Expired Hair Developer
If your developer has gone bad, you may notice the following:
- Change in Color: The developer may have changed color, often appearing darker or yellowish.
- Change in Consistency: It could become thicker or thinner than its original consistency.
- Unusual Odor: A bad smell can indicate that the developer has gone bad.
- Reduced Effectiveness: The developer may not lighten hair as effectively as it should.
- Separation: You may observe a separation of the liquids, where water and peroxide start to separate.
What To Do If Hair Developer Has Gone Bad
If you suspect that your hair developer is expired, it's best to discard it and buy a new one. Using expired developer can lead to:
- Ineffective Hair Color: The desired hair color result may not be achieved.
- Hair Damage: Expired developer may damage the hair and cause dryness.
- Scalp Irritation: It can cause scalp irritation or allergic reactions.
Key Takeaways
| Condition | Shelf Life | Notes |
|---|---|---|
| Unopened Hair Developer | 3 years | Store in a cool, dark place |
| Opened Hair Developer | 6 months | Use within six months for the best results, keeping it tightly sealed and stored well |
