You made a beautiful batch of infused oil or butter, tested it, dialed in your dosing, and put it away for later. Weeks later, that same recipe doesn't quite hit the same. You're not imagining it. Your infusion is genuinely losing potency while it sits in the cabinet, and the main culprit is a chemical process happening whether you're watching or not: oxidation.
Here's what's actually going on, what the research says about slowing it down, and a few practical changes that can meaningfully extend how long your infusions hold their potency.
The Quick Version
- Oxidation is the culprit. THC and CBD slowly convert into other compounds — most notably CBN — when exposed to oxygen, heat, and light. A 2023 accelerated-storage study found unprotected cannabis flower lost 34.3% of its THC over about 4 months.[1]
- Antioxidants slow it down. A 2020 hempseed oil study found antioxidants cut fatty-acid oxidation by up to 79% and more than quadrupled CBDA's measured half-life under heat stress.[2]
- Ascorbyl palmitate is one option — a food-grade, oil-soluble form of vitamin C that blends easily into infused oils and butters, and it doesn't interfere with tCheck's measurements.
- Storage matters too: dark containers, minimal headspace, cool temperatures, and tight seals all help.
- Bottom line: the surest way to know your infusion is holding up is to test it, not guess.
What's Actually Happening: Oxidation Is Eating Your Cannabinoids
THC and CBD aren't chemically stable forever. When exposed to oxygen, heat, and light, they slowly degrade and convert into other compounds. Most notably, THC oxidizes into CBN (cannabinol), a related cannabinoid with much weaker psychoactive effects. That conversion is a big part of why old cannabis and old infusions feel different: not necessarily less "there," but shifted toward a different profile.
A 2023 accelerated storage study of cannabis flower[1] tracked Δ9-THC loss over about 4 months: unprotected samples lost 34.3% of their total THC while samples with antioxidants maintained their potency much better. The study used flower under controlled, accelerated storage, so a home-stored infusion won't necessarily degrade at the exact same rate, but the direction of the effect is well established.
The same degradation pathway plays out in infused oils and butters, too. How fast depends on the carrier fat, temperature, light exposure, oxygen, and packaging.
The Fix: Antioxidants Slow the Clock
If oxidation is the problem, antioxidants are the natural countermeasure. The same principle that keeps cooking oils from turning rancid works on cannabinoids too.
A 2020 study in Scientific Reports[2] tested this directly in hempseed oil, comparing three antioxidants: BHT, alpha-tocopherol (vitamin E), and ascorbyl palmitate against unprotected controls. The antioxidants cut the rate of fatty-acid oxidation by as much as 79%, and alpha-tocopherol extended CBDA's measured half-life under heat stress from about 4 days to roughly 17, more than quadrupling it.
Where Ascorbyl Palmitate Fits In
In our lab, we've been working with ascorbyl palmitate, a fat-soluble form of vitamin C. It's a food-grade antioxidant already used commercially to keep oils and fats from turning rancid, and because it's oil-soluble, it dissolves nicely into an infused oil or butter.
In the hempseed oil study above, ascorbyl palmitate was the mildest of the three antioxidants tested. Alpha-tocopherol and BHT performed better at high temperatures but ascorbyl palmitate still measurably slowed degradation, and it has real practical advantages: it's widely available, inexpensive, and easy to source as a food-grade powder.
In our own lab, we use ascorbyl palmitate at 0.05% by weight. For an 8 oz (230mL) batch of infused oil, that works out to about 100 mg. In volume terms, that's about 1/16 teaspoon of powder. That's a small enough amount that a typical kitchen scale won't measure it well; so you need a scale that reads down to 0.01 g (like the one in the tCheck flower testing expansion kit). And if you're planning to test the finished infusion, ascorbyl palmitate doesn't interfere with tCheck's measurements, so you can use both together without worrying about a skewed reading.
Timing matters, too: ascorbyl palmitate dissolves more readily in warm oil, so we recommend stirring it in during the infusing process itself rather than trying to mix it into the oil after everything has cooled.
Practical Storage Tips That Actually Move the Needle
The research points to the same short list of culprits that degrade your infused oil: oxygen, heat, and light are the three things degrading your infusion, so the fix is to limit exposure to all three.
- Use a dark or opaque container. Amber or cobalt glass blocks much of the UV and visible light that drives oxidation; clear containers offer far less protection.
- Minimize air exposure. The more air sitting on top of your infusion, the more oxygen is available to react with it. Smaller containers filled closer to the top, or transferring to a smaller jar as you use it up, both help.
- Keep it cool. Heat speeds up every degradation reaction in this article The hempseed oil study's numbers got dramatically worse as temperature rose. A cool pantry beats a spot near the stove. Refrigeration or freezing may extend storage further, depending on the carrier oil.
- Consider an antioxidant additive. Food-grade ascorbyl palmitate or a mixed-tocopherol vitamin E blend can provide ongoing protection when stirred in during infusing, while the oil is still warm (ascorbyl palmitate dissolves poorly once the oil has cooled).
- Seal it tightly. Every time a jar is opened, fresh oxygen gets introduced. Airtight lids and minimizing how often you open the container both help slow the cumulative exposure.
None of these steps stop oxidation entirely but they can meaningfully stretch out how long your infusion stays close to its original strength.
The Bottom Line
Cannabinoids degrade through oxidation — that much is well documented. Cooler storage, less light, less air exposure, and a food-grade antioxidant like ascorbyl palmitate can help slow that process down dramatically. Since every kitchen and every batch is different, testing your infusion's potency right after you make it is the most accurate method.
Know Your Potency Before You Dose
The tCheck Potency Tester measures THC or CBD in supported infusions in about 2 minutes — the fastest way to see whether your storage strategy is actually working.
Get the tCheck Potency Tester →References
- [1] Bueno, J., Alborzi, S., & Greenbaum, E. A. (2023). Vapor Phase Terpenes Mitigate Oxidative Degradation of Cannabis sativa Inflorescence Cannabinoid Content in an Accelerated Stability Study. Cannabis and Cannabinoid Research, 8(5), 887–898. DOI: 10.1089/can.2021.0207 · PubMed PMID: 35384716
- [2] Singh, A. et al. (2020). Antioxidants help favorably regulate the kinetics of lipid peroxidation, polyunsaturated fatty acids degradation and acidic cannabinoids decarboxylation in hempseed oil. Scientific Reports, 10, 10567. DOI: 10.1038/s41598-020-67267-0 · PubMed PMID: 32601363
A note on sourcing: the specific figures above come from the cited peer-reviewed studies, measured under controlled laboratory conditions. They describe what happened in those experiments, not a guaranteed outcome for any individual home infusion.
