How to Tell If Cannabis Is Past Its Prime

Cannabis doesn’t usually spoil the way food does, but over months and years its flavor, texture, and strength can alter. It’s also possible for it to develop mold.

Using older cannabis generally won’t create serious health problems for most people without underlying medical issues.

That said, aged weed often shows a clear decline in potency, which matters most for those relying on it therapeutically.

Keep reading to find out how long cannabis stays at its best and how to spot when it’s past its prime.

How long does it stay fresh?

When kept correctly (see storage tips below), dried cannabis typically remains in good condition for about 6 months to a year. Over time its smell and strength gradually fade.

Older studies suggest THC content drops with age — roughly 16 percent lost after one year, with continued declines afterward:

• Approximately 26 percent THC lost after two years
• Roughly 34 percent THC lost after three years
• About 41 percent THC lost after four years

How can I tell if my stash is old?

The easiest sign is the smell. Cannabis that has aged will often smell different or have little to no aroma. Some older buds can also taste harsh.

Appearance and feel offer clues, too. Fresh cannabis shouldn’t fall apart into powder or feel overly spongy when broken apart. If it does, it’s likely too dry or has absorbed too much moisture.

Eating or inhaling old weed usually won’t hurt healthy individuals, but expect changes in texture and reduced effects. The main exception is cannabis that’s developed mold, which can be harmful.

How do I inspect for mold?

Carefully examine your buds.

Mold can be difficult to spot without close inspection. It often appears as small white, powdery, or fuzzy patches.

Moldy cannabis commonly emits a musty odor, similar to hay, and can taste off.

Even relatively new cannabis should be checked. A study from researchers at the University of California, Davis detected bacteria and mold on 20 cannabis samples purchased from dispensaries and growers in Northern California.

Mold exposure from weed is unlikely to cause serious issues for most people but can trigger nausea, vomiting, and coughing.

People with compromised immune systems face greater risk — inhaling smoke or vapor from contaminated cannabis could lead to severe illness or, in rare cases, death.

If your cannabis looks or smells questionable, it’s safer to discard it, even if it’s recently purchased.

What’s the best way to store cannabis?

Light, humidity, temperature, and oxygen all influence cannabis and can change its smell, flavor, and potency over time.

Below are key storage recommendations to help your stash remain fresh and preserve quality for longer.

Pick the proper container

Avoid plastic baggies and containers. Plastic can create static that damages fragile trichomes — the tiny crystalline hairs on buds that contain cannabinoids and terpenes — reducing potency.

Skip lightweight tins as well; they often allow too much air exchange.

Glass jars with airtight lids, such as mason jars, are ideal. They don’t generate static and limit oxygen exposure. They’re also affordable and easy to source.

Many dispensaries sell purpose-built containers designed to keep cannabis fresher for extended periods.

If you have children or pets at home, choose a container that’s child- and pet-resistant.

Control humidity

Cannabis stores best at a relative humidity around 59 to 63 percent. Higher humidity risks trapped moisture and mold growth, while lower humidity dries buds out.

If you want extra protection, include humidity-control packs in your jars. Some people also use humidors made specifically for cannabis.

Keep it cool, dark, and dry

Where you place your cannabis is as crucial as the container.

Direct sunlight accelerates degradation, and excessive heat can retain moisture and encourage mold.

Conversely, storage that’s too cold can make buds brittle and cause trichomes to break off, so refrigerators and freezers are not recommended.

Aim to keep cannabis in a dark cabinet or closet at temperatures below about 77°F (25°C).

What about freezing it?

While freezing preserves many items, it’s not ideal for cannabis.

Freezer temperatures can make trichomes brittle, causing them to snap off when handled.

Freezing can also introduce moisture during thawing, increasing mold risk.

The bottom line

Cannabis won’t necessarily “go bad” if you store it correctly. Kept sealed and protected from heat, moisture, and light, it should remain usable and reasonably potent for up to a year.

Be vigilant for changes in smell, texture, or appearance, and always check for mold before use — if in doubt, throw it out. If you’re concerned about contamination, learn more about issues like moldy weed, how to handle a weed hangover, or symptoms linked to marijuana paranoia.