Medical cannabis for obesity

Obesity is a long-term health condition that can impact every aspect of an individual's life, from their mobility to the way they see themselves. The NHS suggests that living with obesity could lower life expectancy by 2  to 10 years, as well as contribute to the development of conditions like Type 2 Diabetes, arthritis, high blood pressure, and even depression and anxiety. 

A frustrating but common misconception is that obesity is the same as being overweight and can be ‘fixed’ with typical weight loss strategies. However, this disregards the multiple other factors that contribute to a person’s chances of becoming obese, including genetics, underlying conditions (such as PMOS (previously PCOS), hypothyroidism, Cushing's, and more) and psychiatric considerations. These factors can make losing weight the conventional way impractical or unrealistic for those struggling with obesity without clinical intervention. 

This isn’t to say there is no hope for those struggling with obesity, and the rise of prescription weight loss drugs shows that alternative treatment options should be considered when treating the condition, and medical cannabis may be a promising contender.

How can cannabis based-treatments help?

The use of medical cannabis to treat obesity might seem strange since it’s more commonly associated with increased appetite. However, early studies have shown promise in the potential of THCV-based cannabis treatments as an alternative or complementary obesity treatment due to its anorectic effects. 

Studies into the therapeutic uses of THCV for obesity are still ongoing, but early research suggests the way it blocks the CB1 receptors in the brain may tone down hunger signals that can be stimulated into overdrive by THC. These studies also revealed the potential impacts the cannabinoid may have on blood sugar levels, energy metabolism, and even how the brain responds to food, making it an appealing alternative for those struggling with conventional obesity treatments.

What is Obesity

Obesity is a long-term weight-related condition which is categorised as having more body fat than your body needs, and a 2024 NHS report revealed 30% of adults in England were living with obesity. 

Healthcare professionals in the UK use the Body Mass Index (BMI) to score whether an individual is a healthy weight. Initially this scoring system was created with white populations in mind, so the thresholds vary for those from South Asian, Chinese, other Asian, Middle Eastern, Black African or African-Caribbean background who are more prone to central adiposity (fat around the abdomen and organs) and cardiometabolic risk occurs at a lower BMI.

For white populations, the BMI scores class:

• A BMI of 18.5 to 24.9 as the ideal range for average, healthy adults 

• A BMI of 25 to 29.9 as overweight 

• A BMI of 30 to 34.9 as obesity class 1 (obese)

• A BMI of 35 to 39.9 as obesity class 2 (moderately obese)

• A BMI of 40 or more as obesity class 3 (severely obese or morbidly obese)

For populations with South Asian, Chinese, other Asian, Middle Eastern, Black African or African-Caribbean backgrounds, the BMI scores class: 

• A BMI of 18.5 to 22.9 as the ideal range for average, healthy adults 

• A BMI of 23 to 27.4 as overweight 

• A BMI of 27.5 to 32.4 as obesity class 1 (obese)

• A BMI of 32.5 to 37.4 as obesity class 2 (moderately obese)

• A BMI of 37.5 or more as obesity class 3 (severely obese or morbidly obese)

It’s important to remember that while an individual's BMI is used to determine their optimal weight, it does not take into account age, sex, fat distribution, and cannot differentiate between muscle (heavier and denser tissue) and fat. 

Living with obesity can take a toll on a person’s physical and mental health. Physical symptoms of feeling breathless, trouble with movement, and fatigue can make it difficult to follow weight loss programmes and exercise routines as well as increasing the risk of other health complications like Type 2 diabetes, osteoarthritis, gout and more. The impact on an individual's mental health can also be hard to live with, including feelings of anxiety, depression, low self-esteem or self-worth, and isolation. 

How is obesity treated in the UK 

Obesity treatment in the UK has evolved over the years as understanding of the condition, its causes, and how it impacts an individual has been observed. 

Treatment can vary depending on a patient’s individual case as underlying causes of obesity may need to be addressed as well as the condition itself. Treatments are intended to help the patient to lose a goal of 5 to 10% of their body weight, and include:

• Weight management programmes (typically with 1:1 coaching, group therapy, or cognitive behavioural therapy)

• Weight loss medications (such as semaglutide, tirzepatide, liraglutide and orlistat.)

• Weight loss surgeries (typically reserved for those with a BMI over 40 or over 35 with other health conditions that could be improved with weight loss)

Eating a healthy, balanced diet is also critical for those managing their weight and can be supported by weight management programmes and nutritionist advice. The treatment a patient receives for obesity will depend on which obesity class they have been categorised in, and what treatments are suitable for them to lose and manage their weight safely. 

Can medical cannabis help with obesity? 

Despite cannabis having an association with increasing appetite, initial studies into medical cannabis for weight management (particularly THCV-based options) have shown surprising potential.

How it works boils down the individual effects of the cannabinoids in cannabis on the body’s endocannabinoid system. THC (tetrahydrocannabinol) is one of the more known cannabinoids that has a psychoactive effect on people, causing the feeling of ‘being high.’ CBD (Cannabidiol) is a non-intoxicating cannabinoid that is legal to buy over the counter provided the product contains no more than 1 mg of each controlled cannabinoid (like THC) per container. THCV is the lesser-known cannabinoid that is getting its time in the spot-light for its potential in treating obesity and diabetes as it may have anorectic effects. 

While THC has been shown to stimulate the CB1 receptors in the brain causing the associated feelings of euphoria, sedation, and increased appetite, THCV is thought to have the opposite effect. Research has shown THCV may block the CB1 receptors, suppressing appetite rather than enhancing it. 

Studies are ongoing, but THCV-based treatments may help those living with obesity have additional options when it comes to managing their condition. 

What does research say? 

Studies into the effects of medical cannabis for treating obesity are still ongoing or have only been completed using smaller source groups. However, the results of these studies have shown promise. 

One such study was carried out in 2025 to observe the potential therapeutic benefits of CBD and THCV administered for 90 days through mucoadhesive oral strips with no changes to diet or exercise in 44 individuals. The results revealed that the use of the CBD/THCV strips were associated with ‘statistically significant weight loss’, including decrease in abdominal circumference, systolic blood pressure, and LDL cholesterol. 

An observational study in 2026 into the association between cannabis and metabolic disease revealed ‘cannabis use was associated with modestly lower observed risks of several metabolic outcomes, particularly among individuals with BMI<25,’ but varied for those in higher BMI groups. However, as an observational study, these findings should be interpreted with caution and further research and clinical trials into medical cannabis and THCV for weight management are needed to truly understand its potential as a treatment option for those living with obesity. 

Risks, and who it may not suit 

No treatment option is ever truly risk free. Different people can respond differently to different medicine, and what works for some will not work for others. The 2026 Biobank study also observed that moderate cannabis use in people with a BMI over 30 was linked to a possible higher risk of metabolic disease and high blood pressure. 

Another drug that blocked the same receptors (rimonabant) was withdrawn in 2008 over concerns about mental health side effects as it was associated with an increased risk of anxiety and depression. 

Other potential side effects of THCV treatment observed are:

• Diarrhoea or upset stomach

• Dizziness

• Fatigue

• Anxiety 

• Increased heart rate

• Dry mouth (as with other cannabinoids)

These potential side effects mean THCV-based treatments may not be suitable for everyone, especially if you are currently taking medications. Always tell your doctor what medications you are taking before any treatment plan is devised as some prescription and over the counter medicines can interact negatively with cannabis, increasing the risks of side effects. 

Medical cannabis treatment for obesity is not for everyone, and individuals may be ineligible for treatment if they : 

• Have a history of psychosis, bipolar disorder, or schizophrenia 

• Are pregnant or trying to conceive

• Are breastfeeding

Medical cannabis and conditions linked to obesity

The conditions linked to obesity are part of what makes the condition so complex and the needs for treatments to be more nuanced. Medical cannabis can be prescribed by a specialist for a number of qualifying conditions, some of which overlap with those associated with obesity. 

Those who live with obesity can experience joint pain, and has been associated with a higher risk of developing osteoarthritis. The use of medical cannabis for arthritis may help patients find relief from their symptoms when prescribed and monitored by a specialist. 

The use of medical cannabis for depression is another condition that a specialist doctor can prescribe for, and those living with obesity can often experience low-mood

It has been suggested that obesity and sleep disorders share a bidirectional relationship, revealing the need for integrated treatments. Specialist doctors can also prescribe medical cannabis for sleep disorders as an alternative option to traditional sleeping medications which may cause unwanted side effects.  

The link between obesity and Type 2 Diabetes has long been known, but most patients are unaware of the potential for cannabis treatments to ease secondary symptoms. While clinical trials observing the use of medical cannabis for Type 2 Diabetes is in its infancy, recent research suggests cannabis may help manage secondary symptoms like nerve pain and problems with sleep.

Can you get medical cannabis for obesity in the UK?

Yes! Since November 2018 it has been legal for specialist doctors on the GMC register to prescribe medical cannabis for a range of qualifying conditions. Lately, this has come to include obesity and weight management. 

While not available on the NHS, you may qualify for medical cannabis treatment if you have been diagnosed with obesity and have tried two or more conventional treatments that have either not had the desired effects or have caused unwanted or unpleasant side effects. 

Certain criteria does need to be met to qualify for treatment, which generally includes:

• Having a detailed medical history available for review

• No previous diagnosis of psychosis, schizophrenia or bipolar disorder

• Not being pregnant or breastfeeding. 

If all these criteria are met, you may be eligible for a medical cannabis prescription.

When to speak to your GP

Obesity as a condition can often be misunderstood, which can cause patients to hold back on speaking with their GP. However, the potential harm obesity can have on a person’s health should not be ignored, and you should speak to your GP if you have a BMI in the  stated overweight or obesity thresholds and: 

• Want help with losing weight

• Your waist is more than half of your height

• You have conditions linked to obesity (pre-diabetes, diabetes, high blood pressure, joint pain, high cholesterol, sleep apnoea or cardiovascular disease)

• You have a family history of obesity 

• You have (or think you may have) an eating disorder (such as binge eating disorder)

Your GP will be able to take an up to date BMI and advise you on how best to manage your condition and what options are available to you. 

The use of THCV and medical cannabis for obesity is still a relatively new idea, and while more studies are needed, its suggested potential as an alternative or complementary treatment cannot be ignored. 

FAQs

Can cannabis cause weight gain?

It can, but cannabis does not cause weight gain directly. Rather, the THC in cannabis may cause increased appetite, which can lead to over-eating, and in-turn, weight gain. 

THCV, however, is thought to have the opposite effect on appetite, which is why weight management treatment is based around THCV instead. 

What type of cannabis is good for weight loss?

THCV is the cannabinoid produced by the cannabis plant thought to block CB1 receptors in the brain and curbing appetite. This is why THCV-based medical treatments are considered for eligible patients for weight management or obesity.

Is cannabis a fat burner?

No, cannabis itself is not a fat burner or directly linked to weight loss. However, how the cannabinoids interact with the body’s ECS may impact appetite, thus contributing to weight loss or gain if you eat more after taking cannabis. 

What are THCV side effects? 

While not a psychoactive substance like THC, THCV-based cannabis treatments can have some side effects, such as decreased appetite, upset stomach, dizziness fatigue, increased heart rate and dry mouth.

However, when prescribed and monitored by a specialist doctor, side effects from THCV-based medical cannabis treatments can be mitigated or avoided. 

Does cannabis lower BMI?

No, cannabis does not directly lower a person’s BMI. Rather, THCV may block the CB1 receptors and limit the body’s hunger signals and curb appetite. Managing diet and exercise are crucial to lowering BMI, and eating less from a decreased appetite may contribute to a lowered BMI. 

Can medical cannabis help with insulin resistance? 

Some observation studies into certain cannabinoids (particularly CBD and THCV) may be associated with lower fasting insulin and a reduction in insulin resistance. However, research is still thin on this, and further studies and clinical trials are needed to properly understand how cannabis may impact insulin resistance.

If you have been considering alternative treatments for obesity or weight management in the UK, you may be eligible for a medical cannabis prescription from Releaf. 

Our quick and easy medical cannabis eligibility checker can tell you if you could qualify for treatment in under 2 minutes, helping you take that first step on a new route to recovery. 

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