UK study finds most products contain less CBD than advertised

In a new study of the CBD content in products on sale in the UK, the majority were found to contain significantly lower concentrations than what was advertised.

Researchers analysed the actual concentrations of CBD in a sample of products on sale in the UK and compared these with the levels advertised.

The majority of products contained significantly lower concentrations of CBD than stated on the label, regardless of product type with few containing ‘within 10%’ of the advertised amount.

In what is thought to be among one of the largest sample sizes to date, researchers analysed the CBD concentration in 63 products sold by 40 different brands in the UK, these included 13 tinctures, 29 oils, 10 e-liquids and 11 drinks. Most were purchased through major UK health food shops and specialist online CBD retailers to give a more representative sample of the products being used by consumers. 

For each tincture and e-liquid, where possible, an oil from the same brand containing similar advertised levels of CBD was purchased to allow for comparison, while ‘potentially eliminating’ manufacturing standards as a ‘confounding factor’. 

CBD levels were analysed in a blind fashion, using high performance liquid chromatography (HPLC) to measure concentrations in aqueous tinctures, oils and e-liquids and gas chromatograhy-mass spectrometry (GC-MS) in drinks. 

The results show that the measured concentrations fell below those advertised in all product types, although oils deviated the least.

Only 8% products had concentrations within 10% of the advertised strength. All others were measured at more than 10% below the advertised concentrations, except for a single oil that was found to contain 50% more CBD than stated. 

Consistent with previous research 

The latest findings support previous studies which have highlighted the inaccuracy of labelling on CBD products internationally, but are strengthened by the larger sample size.

The Centre for Medicinal Cannabis previously warned that as many as six out of 10 CBD products in the UK market may be mislabelled, with a 2022 analysis of 29 products finding that only 38% were within 10% of the advertised CBD content. In addition to this, over half of these products contained ‘measurable levels’ of controlled substances including THC and cannabinol (CBN).

Contrary to this, consumer research conducted in 2019 suggests that most UK consumers believe the products they purchase are ‘high quality’ and contain levels of CBD ‘equivalent’ to those advertised.

“The available evidence consistently suggests that only a minority of products contain CBD concentrations within acceptable limits of what is advertised,” say the authors in the paper’s discussion. 

“It is unclear whether deviations from advertised CBD concentrations are due to discrepancy at the point of manufacture, or degradation afterwards.”

Calls for better regulation 

The researchers go on to say that their findings ‘reinforce concerns’ over the quality of CBD consumer products and may highlight the need for better regulation of the industry. 

Writing in the paper’s conclusion, they state: “The over-labelling of CBD concentrations within UK products highlights the need for improved product standards, which may necessitate clearer legislative guidance on acceptable tolerance limits for advertised CBD concentrations. The magnitude of deviation from advertised CBD concentrations differed between product types but was not related to product price, with CBD-oils deviating less than aqueous tinctures, e-liquids and drinks.”

They add: “Future research may seek to determine rates of CBD degradation in consumer products, and within-product variability in labelling accuracy. Furthermore, CBD used in research investigating its psychological or physiological effects should be analysed to confirm that CBD concentrations are appropriate.” 

Read the full study here 

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