A jar of Special Sauce hemp flower with text that reads "Cannabinoid Oxidation: What you should know"

What does the “best by” date on your jar of hemp flower mean? Can the cannabinoids— the active ingredients inside— expire? The short answer is, yes, sort of. While the flower itself isn’t going to go bad for quite some time, the cannabinoids that you’re buying the flower for (whether CBD or THC) can oxidize and lose potency. Understanding cannabinoid oxidation and its factors is crucial to keeping your flower fresh and stable.

In this post, we’re going to cover,

  • What cannabinoid oxidation is
  • How oxidation changes THC and CBD
  • And, how to prevent your flower from oxidizing

What Is Cannabinoid Oxidation? 

Oxidation is a chemical process that occurs when cannabinoids are exposed to environmental factors, mainly air, UV light, and heat. Oxidation has more than a few definitions, but when we talk about organic compounds like cannabinoids we mean that the cannabinoid is either losing hydrogen (H) atoms or gaining oxygen (O) atoms. 

Cannabinoid Oxidation Is Not Decarboxylation

While heat can play a major role in both oxidation and decarboxylation, the two processes are not the same. Decarboxylation occurs when we use heat to make an acidic cannabinoid like CBDa drop its extra carboxyl ring group (COOH) and activate it so that our endocannabinoid system can use it. 

Oxidation is a slower process and can happen to both acidic cannabinoids and activated cannabinoids (with much different results!) 

What Causes Cannabinoids To Oxidize?

Several environmental factors can cause the cannabinoids in your hemp to oxidize. Most of them relate to how you store your hemp

UV Light Exposure

UV light can accelerate the oxidation process. When you expose hemp flower and cannabis to light, high-energy photons bombard the cannabinoids within and can break off hydrogen atoms. 

Air Exposure:

Oxygen, like in the air we breathe (O₂), can also react with cannabinoids in your hemp flower. Cannabinoids, being organic compounds, can experience oxidative stress just like our bodies. 

Learn more about how functional mushrooms can help reduce oxidative stress

Excessive Heat

Higher temperatures can accelerate chemical reactions like oxidation. If your hemp or cannabis flower is exposed to heat (like in the trunk of your hot car) it may lose some potency! 

Related: Can CBD Oil Expire? 

Oxidized Cannabinoids: THC And CBD

The two best-known cannabinoids, THC and CBD, are both sensitive to oxidation and can turn into different cannabinoids altogether. 

THC Oxidation: Drop The “TH” 

When we expose THC to the elements it can oxidize and turn into cannabinol (CBN). This transformation not only affects THC’s psychoactive properties, but CBN can also counteract some of the unwanted side effects of THC consumption.

THC (C₂₁H₃₀O₂) > oxidation > CBN (C₂₁H₂₆O₂)

CBN isn’t necessarily a bad byproduct though. Some research suggests that this unique cannabinoid may have a host of benefits all on its own. We here at Sunset Lake have combined CBN together with CBD to make our best-selling CBN-infused Sleep Gummies as it’s believed that the two together with melatonin can help get you to bed. 

Sunset Lake CBD Sleep Gummies with CBN (oxidized THC) and CBD on a blue background

CBD Oxidation: Add A “Q”

Unlike, THC and CBN, when we expose CBD to the elements it can oxidize into hydroxyquinone (HU-331) and potentially other cannabinoids we have yet to isolate and discover.1 

CBD (C₂₁H₃₀O₂) > oxidation > HU-331 (C₂₁H₂₈O₃)

HU-331 is a fascinating molecule that’s been shown to have an effect against oncogenic human cells.2 Without getting too much into the medical nitty gritty, let’s just say cancer researchers should pay some extra attention to CBD oxidation and all of the derivatives it produces. 

How To Slow Cannabinoid Oxidation

Because oxidation is also a function of time, it’s important to note that we can’t stop the process completely. That said, there’s plenty you can do to slow down the process and protect your cannabinoids. 

Airtight Containers:

When choosing storage containers for your hemp or cannabis flower, choose a container with an airtight seal like a mason jar with a matching top, or rubberized Tupperware. 

In The Dark: 

If your chosen container is see-through you’ll also want to store your flower in a dark place away from natural light. Better yet, you can store your flower in an opaque container in the dark. 

Cool Places:

Keep your cannabis and hemp flower in places with cool, stable temperatures. That means don’t store it in your car trunk, or your bathroom’s medicine cabinet. Instead, store your air-tight, opaque containers in a basement or air-conditioned closet.


  1. Schwarzenberg, A., Carpenter, H., Wright, C. et al. Characterizing the degradation of cannabidiol in an e-liquid formulation. Sci Rep 12, 20058 (2022). https://doi.org/10.1038/s41598-022-23910-6
  2. Kogan N.M.; et al. “A Cannabinoid Anticancer Quinone, HU-331, Is More Potent and Less Cardiotoxic Than Doxorubicin: A Comparative in Vivo Study”. J. Pharmacol. Exp. Ther. 322 (2): 646–653. (2007). doi:10.1124/jpet.107.120865.