How Long Does Weed Stay Good? Storage and Freshness Guide

Whether you've stocked up during a sale, found an old stash while cleaning, or just want to make your cannabis last longer, understanding how long weed stays good is essential knowledge for any consumer. Properly stored cannabis can remain potent and enjoyable for months, while improperly stored flower can degrade quickly.

This comprehensive guide covers cannabis shelf life, storage best practices, signs of degradation, and how to maximize the longevity of your supply.

Quick Answer

Properly stored cannabis stays good for 6 months to 1 year, maintaining most of its potency and flavor. After a year, THC begins degrading into CBN (a less psychoactive cannabinoid), and terpenes evaporate. Cannabis stored in a cool, dark, airtight container with controlled humidity (58-62% RH) will last the longest. Old weed won't make you sick but will be less potent and flavorful.

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Table of Contents

• Cannabis Shelf Life Basics
• What Degrades Cannabis?
• How to Tell if Weed Has Gone Bad
• Optimal Storage Conditions
• Best Storage Containers
• Storage Mistakes to Avoid
• Reviving Old Cannabis
• Edibles and Concentrate Shelf Life
• Pro Tips
• FAQ

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Cannabis Shelf Life Basics

General Timeline

Under optimal conditions:

THC Degradation Research

A study published in the Journal of Pharmacy and Pharmacology found that cannabis loses THC at the following rates when stored at room temperature:

• After 1 year: ~16% THC loss
• After 2 years: ~26% THC loss
• After 3 years: ~34% THC loss
• After 4 years: ~41% THC loss

These numbers represent averages—poor storage accelerates degradation, while optimal storage slows it.

What Happens as Cannabis Ages

As cannabis ages, several changes occur:

1. THC converts to CBN: THC oxidizes into CBN (cannabinol), which is less psychoactive but may have sedative properties

2. Terpenes evaporate: The aromatic compounds that give cannabis its flavor and contribute to effects dissipate

3. Moisture loss: Flower becomes dry and brittle

4. Chlorophyll breakdown: Color fades from green to brown

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What Degrades Cannabis?

Four main factors accelerate cannabis degradation:

1. Light

Light is cannabis's biggest enemy. UV rays break down cannabinoids and terpenes rapidly. A study from the University of London found that light exposure was the single greatest factor in cannabinoid degradation.

Solution: Store in opaque containers in dark locations.

2. Air/Oxygen

Oxygen oxidizes cannabinoids, converting THC to CBN. It also dries out flower and allows terpenes to evaporate.

Solution: Use airtight containers with minimal air space.

3. Temperature

High temperatures accelerate degradation and can dry out flower. Very high heat decarboxylates THCA into THC prematurely—fine for edibles, but not ideal for smoking.

Temperatures above 77°F (25°C) can also encourage mold growth if humidity is present.

Solution: Store in cool environments (60-70°F / 15-21°C).

4. Humidity

Too much humidity (above 65%) promotes mold and mildew growth. Too little humidity (below 55%) dries out flower and degrades trichomes.

Solution: Maintain 58-62% relative humidity using humidity packs.

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How to Tell if Weed Has Gone Bad

Signs of Degraded Cannabis

Texture Changes:

• Crumbles to dust when touched (over-dry)
• Feels spongy or doesn't break easily (too moist—potential mold)
• Stems snap instead of bending slightly

Visual Changes:

• Brown or faded color (was once bright green)
• Trichomes appear dull or amber (were once milky/clear)
• Visible mold (white fuzzy spots or webbing)

Smell Changes:

• Musty or moldy smell (dangerous—don't consume)
• Hay-like or grassy smell (degraded terpenes)
• Little to no aroma (terpene loss)

Smoke/Vapor Quality:

• Harsh, unpleasant taste
• Less smooth than fresh flower
• Minimal effects compared to fresh cannabis

When to Throw It Out

Discard cannabis if you notice:

• Any mold (white fuzzy patches, dark spots, or web-like material)
• Musty or "off" smell
• Visible insects or eggs

Moldy cannabis can cause respiratory issues and should never be consumed.

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Optimal Storage Conditions

The Ideal Environment

Temperature: 60-70°F (15-21°C)

• Cool but not cold
• Avoid temperature fluctuations
• Never store near heat sources

Humidity: 58-62% Relative Humidity

• Use humidity control packs (Boveda or Integra Boost)
• 62% for slightly more moisture
• 58% for drier preference

Light: Complete darkness

• Opaque containers preferred
• Dark storage location
• No direct sunlight

Air: Airtight with minimal headspace

• Fill containers appropriately
• Vacuum sealing works for long-term
• Avoid opening frequently

Where to Store Cannabis

Good locations:

• Drawer or cabinet away from windows
• Closet shelf
• Cool basement (if not damp)
• Dedicated storage box

Bad locations:

• Near windows or light sources
• Kitchen (temperature fluctuations)
• Bathroom (humidity fluctuations)
• Car (extreme temperature changes)
• Freezer (controversial—see FAQ)

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Best Storage Containers

Glass Jars (Best Overall)

Pros:

• Airtight seal
• Doesn't affect taste
• Reusable
• Available in opaque/UV-resistant versions

Cons:

• Breakable
• Clear glass needs dark storage
• Static can disturb trichomes

Best options: Mason jars with new lids, UV-protected glass jars, specialized cannabis storage jars

Specialty Cannabis Containers

Purpose-built containers often feature:

• UV protection
• Humidity control
• Airtight seals
• Built-in humidity pack holders

Popular brands include CVault, Herb Guard, and Tightvac.

Titanium/Metal Containers

Pros:

• Light-proof
• Durable
• Airtight options available

Cons:

• Can affect humidity
• Some metals may interact with terpenes
• Often more expensive

What to Avoid

Plastic bags: Static pulls off trichomes, not airtight, plastic can affect taste

Plastic containers: Can cause sweating, may leach chemicals, static issues

Paper or cardboard: Not airtight, absorbs moisture and terpenes

Humidors: Cedar humidors made for cigars can transfer oils that affect cannabis taste

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Storage Mistakes to Avoid

1. Storing in the Freezer

While it seems logical, freezing cannabis causes trichomes to become brittle and break off when handled. If you must freeze for very long-term storage, don't handle until fully thawed.

2. Using Plastic Bags

The worst common storage method. Static electricity attracts trichomes, bags aren't airtight, and plastic can affect taste.

3. Storing Different Strains Together

Strains will blend aromas and potentially transfer moisture. Keep each strain in its own container.

4. Overfilling or Underfilling Containers

Overfilling causes compression damage. Underfilling means more oxygen exposure. Fill containers about 75% full.

5. Using Desiccants Without Humidity Packs

Regular desiccants (silica gel) can over-dry cannabis. Use two-way humidity packs that both add and remove moisture as needed.

6. Grinding Before Storage

Ground cannabis degrades much faster than whole flower due to increased surface area exposure. Only grind what you'll use soon.

7. Checking Too Frequently

Every time you open the container, you introduce fresh air and allow terpenes to escape. Access only when needed.

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Reviving Old Cannabis

If your cannabis has become too dry, you can attempt to rehydrate it:

Humidity Pack Method (Safest)

1. Place dry cannabis in an airtight container

2. Add a 62% humidity pack (Boveda or Integra Boost)

3. Seal and wait 24-72 hours

4. Check moisture level and repeat if needed

Fruit Peel Method (Use Carefully)

1. Place a small piece of orange or lemon peel in the container

2. Don't let peel touch the cannabis

3. Check after 1-2 hours

4. Remove peel promptly to avoid mold

Warning: This method can introduce moisture too quickly and promote mold. The humidity pack method is safer.

Lettuce/Tortilla Method

Similar to fruit peels—place moist (not wet) lettuce or a tortilla in the container briefly. Remove after a few hours.

What You Can't Fix

Rehydration can restore some moisture, but it cannot:

• Restore lost THC (already degraded to CBN)
• Bring back evaporated terpenes
• Fix moldy cannabis (never try to save it)

Old cannabis will always be less potent and flavorful than fresh, regardless of rehydration.

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Edibles and Concentrate Shelf Life

Edibles

Commercial edibles typically include a best-by date. General guidelines:

• Baked goods: 1-2 weeks (refrigerate)
• Gummies/candies: 6-12 months (cool, dark storage)
• Chocolates: 6-12 months (avoid heat)
• Beverages: Check expiration date
• Tinctures: 1-3 years (store in dark, cool place)

Concentrates

Concentrates typically last longer than flower:

• Shatter: 6-12 months (airtight, cool storage)
• Wax/Budder: 6-12 months (avoid heat which causes consistency change)
• Live resin: 6-12 months (refrigerate for best preservation)
• Rosin: 3-6 months at room temp, longer if refrigerated
• Distillate: 1-2 years (very stable)

For more on concentrate storage, see our storing concentrates guide.

Vape Cartridges

Cartridges last 6-12 months when stored upright in a cool, dark place. Avoid leaving in hot cars.

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Pro Tips

1. Label your containers with strain name and purchase date

2. Invest in quality storage from the start—it pays off in preserved potency

3. Buy humidity packs in bulk—they're affordable and essential

4. Keep a storage jar for each strain you regularly purchase

5. Store in a dedicated drawer away from daily-use items

6. Don't store cannabis with grinders or pipes—residue creates unwanted smells

7. Buy smaller quantities if you consume slowly—fresh is always better

8. Vacuum seal for long-term storage (months+)

9. Check stored cannabis monthly for any signs of mold

10. Write "opened" date on containers to track freshness

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FAQ

Can old weed make you sick?

Old weed that's simply dried out won't make you sick—it's just less potent and harsher to smoke. However, moldy cannabis can cause respiratory issues, allergic reactions, or infections. Never consume cannabis with any signs of mold.

Is it safe to smoke really old weed?

If there's no mold, it's safe but likely not enjoyable. The smoke will be harsh, effects diminished, and flavor poor. It won't hurt you, but fresh cannabis is always preferred.

Does weed expire?

Cannabis doesn't "expire" like food that becomes dangerous. It degrades—losing potency, flavor, and smoothness over time. Think of it like spices that lose flavor rather than food that spoils.

Should I freeze my cannabis?

Generally, no. Freezing makes trichomes brittle and they break off when handled. If you must freeze for very long-term storage (6+ months), vacuum seal first and don't handle until fully thawed.

How long do Boveda packs last?

Boveda packs last 2-4 months in regularly opened containers, or 6-12 months in sealed containers. They're spent when they feel crunchy instead of squishy.

Does keeping weed in the fridge help?

Refrigerators can work but aren't ideal. The temperature fluctuations when opening and humidity levels can cause issues. A cool, dark cabinet is usually better.

How do dispensaries store their cannabis?

Professional dispensaries use climate-controlled storage with optimal temperature and humidity, often in large containers with humidity control. They rotate stock to sell oldest inventory first.

Can I store cannabis with other herbs?

No. Strong herbs like mint or lavender will transfer aromas to your cannabis, affecting its flavor. Keep cannabis in its own dedicated container.

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Conclusion

With proper storage, cannabis can remain potent and enjoyable for up to a year—sometimes longer. The keys are controlling light, air, temperature, and humidity. Invest in quality airtight containers, use humidity packs, store in a cool dark place, and only grind what you'll consume soon.

While old cannabis won't harm you (unless moldy), fresh flower provides the best experience. If you find yourself with degraded cannabis, you can attempt rehydration, but you can't restore lost cannabinoids and terpenes.

For related storage information, check out our guides on proper cannabis storage containers or browse our strain database to find new varieties to add to your collection.