Fall 2020

Clinical Matters: Too Much of a Good Thing?

Determining When a THC Tolerance Break Is Needed

We have all seen the transformative power of cannabis to help patients. The cannabinoids, terpenes, flavonoids, and other plant compounds can have a profound positive impact on healing. Medical users also benefit from cannabis’s euphoric and relaxing effects that recreational users have long since known.

But what about the opposite end of the spectrum, when we’re treating someone who’s using increasing amounts of cannabis but who is no longer experiencing beneficial outcomes?

When the Endocannabinoid System Gets Out of Balance
Let’s first review the role THC plays with our endocannabinoid system (ECS). As cannabis practitioners, we educate patients about how our ECS is designed to provide homeostasis. The ECS plays an important role in regulating metabolism, sleep, mood, immunity, and inflammation, along with other functions.

Two types of cannabinoid (CB) receptors make up the majority of the ECS. CB1 receptors are located in the central nervous system, while CB2 receptors are found throughout the body, helping control inflammation and immune response. Both endogenous cannabinoids and the cannabis plant’s cannabinoids bind to the CB1 and CB2 receptors, creating an effect on the brain and body.

In most cases, these effects are desired and help to restore homeostasis to the system. For example, pain, nausea, or inflammation may be reduced in chronically ill patients who use cannabis to manage their symptoms. For recreational users, the intoxicating effects of THC may result in an uplifted mood, creativity, or focus, depending on the particular plant chemovar.

However, when the ECS is flooded with too much THC over long periods of time, the ECS’s CB1 receptors can become desensitized and rapidly internalized. In this case, the CB1 receptors are downregulated and go into hiding as a result of too much THC. The ECS is no longer in balance, and the high levels of THC prevent the ECS from rebalancing itself without intervention.

To bring back balance, it’s necessary for THC to detach from the CB1 receptors, thereby allowing the CB1 receptors to recycle and upregulate.1 The most effective way to achieve this is by taking a cannabis tolerance break.

Is It Time for a Tolerance Break?
When assessing whether someone can benefit from a tolerance break, the key considerations are whether a medical patient is still having optimal symptom control and if the recreational user is still experiencing enjoyment from their cannabis use.

I’ve met with many patients who use low, moderate, or even higher amounts of THC who report satisfactory symptom control. In this case, their cannabis regimens are working for them and there would be no benefit from taking a break.

On the other hand, when patients say they’re no longer feeling a benefit from cannabis, it’s necessary to question whether a tolerance break is warranted. Often patients will report they’re not gaining the same positive effects from cannabis as in the past—even after increasing their usage, moving to more concentrated products, modifying timing, or changing routes. Nothing provides the euphoria or pain relief they previously achieved with cannabis. Their increased use may be interfering with their daily activities as well, and they’re spending more money on higher-potency THC without getting the desired results.

What’s an Optimal Length of Time for a Tolerance Break?
Several factors come into play when determining the optimal length for a cannabis tolerance break. Dustin Sulak, DO, an expert in cannabis medicine, suggests a two-day cannabis fast.1 For people who use cannabis medicinally and can’t be off THC for very long due to the severity of their symptoms, two days might be an ideal tolerance break. Data show that CB1 upregulation begins almost immediately after discontinuation of cannabis.2,3 Most people feel comfortable committing to 48 hours.

On the other hand, in most clinical practice, two-week tolerance breaks are typically suggested. However, it’s also known that THC remains in the system for about 30 days. Based on those data, some practitioners suggest four weeks as optimal for full CB1 receptor recovery.2

All of this is to say there’s not a one-size-fits-all answer. When working with patients, we want the break to last long enough to allow CB1 receptor upregulation to happen while also being sensitive to each patient’s particular needs.

Whether to Taper or Go Cold Turkey
Patients often ask whether they can simply cut back on their use to give their CB1 receptors a chance to upregulate, wondering if it’s really necessary to take a complete break from cannabis. Based on available research, a full break is optimal.3 The ECS of heavy chronic users continues to be flooded with excess THC, even when cannabis consumption is reduced.

Practitioners may offer heavy cannabis users the alternative to cut down on their use simply as a way for the patient to wrap their head around the idea of taking a break in the future. They can see whether they gain any benefit from reducing cannabis use and begin modifying a ritual that has become more of a habit than a need.

Certainly, if someone came to me and said they didn’t think they could quit their cannabis use for two days, I’d suggest tapering down as a first step: “Let’s see if you can hold off consuming for an hour upon waking and really take note of how you’re feeling.” From there, I might encourage the patient to stretch the time between consumption to three hours, then four hours. It can be very individualized to meet each patient where they are.

Taking a tolerance break can be very difficult for heavy cannabis users, not just physically but also emotionally. Sulak advises patients to celebrate the last dose before their cannabis fasts and approach the tolerance break with intention.1 After all, they are allowing their body to reset itself naturally.

I also suggest that patients try to stimulate their ECS in other ways—through meditation, exercise, hydration, and a healthful diet. It’s all about trying to restore balance.

The Role of Education in a Successful Tolerance Break
Many people think budtenders are the ultimate cannabis experts, but some budtenders are unaware of the ECS, and wouldn’t realize that chronic heavy cannabis use can reduce the effects of THC, whether the goal was euphoria or relief.

When our Leaf411 nurses spoke with budtenders at popup events and educated them about the ECS, it was like a lightbulb turned on. As a result, several said they were interested in cutting down on their use, not only to reset their system but also to reduce their consumption cost and maybe have a chance to feel that euphoria again—something they’ve been seeking for quite some time.

It’s important to always offer education on the ECS, even when talking to experienced cannabis users, because many people don’t fully understand how THC affects this system. More is not always better, or even more effective, and educating patients about the biphasic effect of cannabis is also important.

Planning for Success After a Tolerance Break
It’s important for patients to “start low and go slow” when they have completed their cannabis tolerance breaks; otherwise, they can quickly lose all benefits from the break. They should begin with a microdose, a lesser quantity. This allows the THC to be absorbed by the CB1 receptors without overwhelming them again. The receptors come back to life, allowing patients to feel the THC more strongly.

The benefit to patients is two-fold. Most important, they’re able once again to experience the full benefit of the plant once their ECS is back in balance and the CB1 receptors are upregulated. Additionally, there’s a cost savings, since a little bit of THC can go a lot farther than before.

— Katherine Golden, RN, is the CEO, executive director, and cofounder of Leaf411, the nation’s first cannabis nurse hotline. She has multiple certifications in cannabis education by Radicle Health, The Medical Cannabis Institute, Healer, and Green Flower and is a member of the American Cannabis Nurse Association, Cannabis Nurses Network, and the Society of Cannabis Clinicians. The author wishes to acknowledge the assistance of Denise Gonzales-Walker in the preparation of this article.


1. Sensitization six day protocol.  

2. D’Souza DC, Cortes-Briones JA, Ranganathan M, et al. Rapid changes in CB1 receptor availability in cannabis dependent males after abstinence from cannabis. Biol Psychiatry Cogn Neurosci Neuroimaging. 2016;1(1):60-67.

3. Hirvonen J, Goodwin RS, Li CT, et al. Reversible and regionally selective downregulation of brain cannabinoid CB1 receptors in chronic daily cannabis smokers. Mol Psychiatry. 2012;17(6):642-649.


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