The Use of Cannabis Flower in the Treatment of Fatigue

New Research on Cannabis Flower for Fatigue

Despite still being prohibited at the federal level in the USA, medical cannabis is now widely available across the country. Over two-thirds of states have now legalised the medicinal use of the plant while over two-thirds of Americans also now live in a state where recreational cannabis is legal. Despite this widespread availability, however, federal prohibition continues to present significant barriers to the execution of clinical investigations into the effects of cannabis, including its medical properties. As a result, there remains a lack of evidence.

The use of medical cannabis has become increasingly popular for a number of conditions and illnesses of which fatigue is a major symptom. Patient testimony and other evidence collected from patients with chronic pain, cancer, Parkinson’s disease, and multiple sclerosis show an association between medical cannabis and increased energy levels.

In order to understand the true effects of medical cannabis for fatigue, researchers from the University of New Mexico aimed to measure for the first time how commercially available cannabis flower products affect fatigue levels in real time. The results of the study were recently published in Medical Cannabis and Cannabinoids. 

Design and Methods of the Study

The researchers used data collected through the Releaf App – a mobile software application which has become the largest database of real-time effects of cannabis for medical use in the USA. The Releaf App was designed to help medical cannabis users monitor the variable effects of cannabis-based products. It allows patients to record product types, routes of administration, and labelled cannabis phenotypes and cannabinoid content of the products used. The app also records the conditions for which patients are consuming cannabis, real-time symptom intensity levels prior to and following consumption, and any side effects experienced.

Prior to consuming cannabis, patients are prompted to enter the details of their medical cannabis products. Upon starting a session, the user then specifies the symptoms for which they are administering cannabis and reports a symptom intensity level (scored on a visual analog scale from 0-10). The symptom intensity score is then updated following consumption of the cannabis product, alongside the recording of any side effects experienced. The user can update the symptom intensity score as frequently as they like.

For this study, researchers assessed data from reports where cannabis flower was used and where ‘fatigue’ was reported as a symptom. The main study outcome was the change in user-reported symptom intensity level following cannabis use. The researchers also characterised the 47 side effects (as listed by the app) in to ‘negative side effects’, ‘positive side effects’, and ‘context-specific side effects’ (side effects that cannot be easily characterised as positive or negative. E.g., feeling “tingly”).

Results of the Study

On average, participants reported a starting symptom intensity level of 6.08. In comparison, the average ending symptom intensity level was 2.6, suggesting an average symptom relief of 3.48 – a significant reduction. Furthermore, while a majority of patients (68%) also reported at least one negative side effect, 96% of patients reported at least one positive side effect, and 81% reported at least one context-specific side effect. 

The most common negative side effects reported were dry mouth (32%) and feeling foggy (24%); the most commonly reported positive side effects were feeling relaxed (62%) and feeling peaceful (55%); and the most commonly reported context specific side effects were euphoria (46%) and feeling ‘tingly’ (32%).

Effect by Cannabis Product Characteristics

The researchers also compared the effects of cannabis on fatigue symptom relief depending on the products and administration method used. The results indicate that CBD and THC levels were unable to explain any difference in fatigue symptom relief. Overall, the data also indicates that people who used ‘joints’ experienced higher fatigue symptom relief than those who used pipes or vaporisers; however, the researchers note that this could be related to several other factors. In the UK, medical cannabis flower is exclusively recommended to be administered using a medical-grade vaporiser due to the negative health implications due to smoking. 

The use of Indica products was generally associated with a higher reporting of negative side effects and a potential increase in context-specific side effects. In comparison, Sativa products were weakly associated with increased reporting of positive side effects. Similarly, high-CBD products were associated with a decreased reporting of negative side effects. 

User Specific Outcomes

Around 72% of the sessions analysed in this study included user characteristics. From this dataset, the researchers discovered that male users experienced greater symptom relief compared with female users. Symptom relief did not, however, seem to differ by user age or user experience.


These findings, collected from the largest database of real-time effects of cannabis in the US, demonstrate that the use of whole, dried cannabis flower was associated with fast-acting reduction in severity of fatigue. While some participants reported an increase in fatigue, the vast majority (92%) reported an overall decrease in their perceived fatigue intensity levels. 

In the overall sample and for all subgroups except inexperienced users, THC, CBD and plant phenotypes (C. Indica and C. Sativa) were not found to significantly affect symptom relief. The authors suggest that non-cannabinoid compounds, such as terpenes and terpenoids, therefore may also play a role in the regulation of fatigue, or the relationship between CBD and THC, and fatigue.

While this study presents promising evidence to support the effects of cannabis on fatigue symptoms, the researchers do note some limitations. Firstly, this study did not compare the sample of current medical cannabis users with patients who did not use cannabis. Furthermore, it is possible that patients who administer cannabis for symptoms of fatigue, or have failed benefit from alternative therapies, may be more likely to report positive effects from cannabis. The researchers were also unable to differentiate between the effects of different phytochemicals of the cannabis plant.

Overall, the researchers conclude that cannabis may present an option for patients suffering with fatigue. This may further support the use of medical cannabis in patients with conditions where fatigue is a key symptom, such as cancer, multiple sclerosis, Parkinson’s disease, and chronic pain. However, randomised controlled trials are still required to confirm this effect.