Thermal paste is a vital yet often overlooked PC component. It helps transfer heat efficiently by filling microscopic air gaps between a computer’s circuit boards and their heat sinks. If you’ve purchased used PC parts or performed a DIY upgrade, you may need a tube of thermal paste to ensure proper installation. Likewise, if your laptop starts running hotter than usual or shuts down unexpectedly, replacing the thermal paste could restore optimal cooling.
However, given how little you use for each application, you’re likely to have plenty left over after your repair. That raises an important question: how long does thermal paste last once opened?
Shelf Life of Opened Thermal Paste
In general, a tube of opened thermal paste remains usable for 2–5 years. Some brands advertise up to eight years of shelf life, but it’s better to err on the conservative side.
Before using older paste, check for signs of degradation. If you notice liquid separation, dry flakes, or a strange odor, the compound has likely started to break down and should be replaced. Fortunately, thermal paste is affordable—typical prices range from $10 to $15—so replacing it isn’t a big expense. Proper storage, however, can help extend its usability.
How to Replace Old Thermal Paste
In most cases, the factory-applied paste on CPUs or GPUs lasts for years. You might never need to replace it if you frequently upgrade components. But when you do replace your CPU or GPU (and it’s best to buy these parts new), the old paste must be removed before applying a fresh layer.
To clean off the old compound, use isopropyl alcohol and a lint-free cloth. When reapplying, remember: less is more. A pea-sized drop placed in the center of the chip is enough. When you mount the heat sink, gentle pressure will spread the paste evenly across the surface. Alternatively, you can use a small plastic spreader or a credit card for even coverage.
After finishing, seal the paste tube tightly, place it in a Ziploc bag, and store it in a cool, dry place—away from sunlight, high temperatures, or humidity.
Expiration and Storage Tips
Even unopened thermal paste has a shelf life of about four years. Check the product label or packaging for the expiration date. Ideal storage conditions for both opened and unopened tubes are the same: keep them in a temperature-stable, dry environment.
Whether you’re assembling a new PC, upgrading components, or addressing overheating issues, thermal paste plays a crucial role in keeping your system cool and running efficiently. When in doubt about the age or quality of your paste, buying a new tube is a smart and inexpensive way to ensure performance. A popular example is the Arctic MX-4 Premium Performance Thermal Paste, which consistently earns high reviews for reliability and ease of use.
