From the Guidelines
THC is not recommended for weight gain due to limited and inconsistent evidence supporting its effectiveness in improving appetite and weight in cancer patients. The ESPEN guidelines on nutrition in cancer patients 1 suggest that while dronabinol, a synthetic form of THC, may have the potential to improve chemosensory perception and appetite in patients with cancer anorexia, the evidence is not strong enough to support a recommendation.
Some key points to consider:
- A small phase II clinical trial found that dronabinol reduced anorexia in 68% of patients with cancer cachexia, but had a high drop-out rate due to adverse events 1.
- A prospective randomized placebo-controlled multi-center trial found that cannabis extract or THC did not improve appetite or quality of life in patients with advanced cancer and anorexia-cachexia syndrome 1.
- A RCT found that patients treated with progestins had a greater gain in appetite and weight compared to those treated with dronabinol alone, but also had a greater incidence of impotence 1.
- The evidence on the use of THC for weight gain is limited and inconsistent, and other appetite stimulators such as ghrelin and anamorelin may be more effective in improving appetite and weight in cancer patients 1.
Overall, while THC may have some potential benefits in improving appetite and weight in cancer patients, the evidence is not strong enough to support a recommendation for its use, and other treatment options may be more effective.
From the Research
THC and Weight Gain
- The relationship between THC and weight gain is complex and not fully understood 2.
- Acute marijuana use is associated with increased appetite, but the effect on body weight is not always clinically meaningful 2.
- Some studies suggest that marijuana use may stimulate appetite in low-weight individuals, but not in normal-weight or overweight individuals 2.
- Large epidemiological studies have found that marijuana users tend to have lower body mass indices than non-users, although this may be due to various confounding factors 2.
Appetite Stimulation and Weight Gain in Cancer Patients
- Medicinal cannabis has shown promise in improving appetite-related symptoms in people with cancer, but the evidence is limited and inconsistent 3, 4.
- A systematic review of randomized controlled trials found that cannabinoids do not appear to improve appetite, oral intake, weight, chemosensory function, or appetite-related quality of life in cancer patients 4.
- Another study found that dronabinol, a synthetic cannabinoid, improved chemosensory perception and other secondary outcomes related to appetite in cancer patients, but the evidence is not conclusive 3.
Effects of THC on Appetite Hormones
- THC has been shown to increase plasma levels of ghrelin and leptin, and decrease levels of PYY, which are appetite hormones 5.
- These findings suggest that THC may modulate appetite hormones through the endogenous cannabinoid receptors, independent of glucose metabolism 5.
Pharmacokinetics of THC
- The pharmacokinetics of THC after smoking cannabis cigarettes containing high THC doses is not well understood, but studies suggest that there is a linear relationship between THC dose and serum concentration 6.
- THC serum concentrations and pharmacological effects, such as increased heart rate and "high" feeling, have been observed in males after smoking a combination of tobacco and cannabis containing up to 69 mg THC 6.