Conversion of cannabidiol (CBD) to Δ9-tetrahydrocannabinol (Δ9-THC) during protein precipitations prior to plasma samples analysis by chromatography - Troubles with reliable CBD quantitation when acidic precipitation agents are applied

Transformation of Cannabidiol (CBD) during its high-temperature extraction: Studies involving model systems, hemp and functional foods containing CBD

Most approaches to plants and foodstuffs analysis involve the application of liquid extraction methods for the isolation of their components. The present paper shows and discusses the transformations that CBD may undergo during its high-temperature extraction with methanol, dichloromethane, ethyl acetate and hexane from hemp and CBD containing commercially available functional foods. According to the performed research, CBD can transform not only into cannabinoids, which are hemp metabolites (i.e. Δ8/Δ9-THC, CBN), but also into other previously unknown derivatives, the number and quantity of which depend on the type of the extrahent and the oxygen content in the extraction system. In the case of each solvent used, the CBD transformation degree is strongly affected by the humidity of the extracted hemp. The results presented in this work are important both for hemp analysis, including the research dealing with hemp metabolism, but also for functional food containing CBD.

Xenobiotics recovery from plasma using solid phase extraction with C-18 sorbent - The reasons of literature discrepancies

Solid phase extraction (SPE) is one of the most popular methods of preparing plasma samples before determining the xenobiotics they contain. The present paper shows that the recovery degree of xenobiotics from plasma samples using SPE with C18 sorbent strongly depends on their storage time and temperature. While xenobiotics can be isolated and recovered in 100 % from fresh plasma samples under optimal conditions of the SPE procedure, their SPE recovery degree from stored plasma is lower. It diminishes with the time increase and temperature reduction of plasma storage. Moreover, a part of xenobiotic in stored plasma samples is not sorbed on SPE-C18 column at all and leaves it together with the waste during loading the column with the examined sample. According to the NMR data, the main reason of the presence of xenobiotics in the waste of the SPE column during its loading are structural-chemical changes occurring in plasma during its storage, leading to the formation of some complex(es) of hydrophilic character with xenobiotic. Another reason for lower SPE recovery degree of xenobiotic from stored plasma is the formation of plasma sediment, which binds/occludes xenobiotic. The presented results expand the current knowledge on why the SPE recovery degree of xenobiotics from plasma reported in the literature may differ. They are important for proper calibration of the chromatographic system in the analysis of xenobiotics in plasma and for achieving high accuracy of the analytical procedure involving SPE in xenobiotic estimation.

A systematic review of analytical methodologies capable of analysing phytocannabinoids in cosmetics

As cannabidiol (CBD) is not considered to be a drug and because of its potential health claims, it is an interesting compound that is often found in cosmetics. However, the safety of CBD, as well as the presence of trace amounts of other phytocannabinoids, including the psychoactive substance ∆9-tetrahydrocannabinol (THC), is still being debated. A robust analytical technique capable of analysing cosmetic products and determining their phytocannabinoid content will be crucial in assessing the safety of these products. This systematic review aims to highlight the current analytical tools that could be used to analyse phytocannabinoids in cosmetics. The ideal method would be able to analyse high levels of CBD in combination with trace levels of THC and their acids. The method should provide good recoveries and accuracies in a variety of matrices while providing information on up-coming phytocannabinoids such as cannabichromene (CBC), cannabigerol (CBG) and cannabinol (CBN). The systematic review approach was based on the Preferred Reporting Items for Systematic review and Meta-Analyses method. The research focused on studies published from January 2010 to December 2022 in PubMed and Scopus. A total of 15 datasets met the inclusion and exclusion criteria and were tabulated to allow easy comparison. Although some of the reviewed methods can handle multiple matrices and provide satisfactory recoveries, this review process did not identify an ideal method. The most suitable methods either could not quantify phytocannabinoid acids or were not sensitive enough to quantify trace levels of psychoactive phytocannabinoids.

Factors influencing the in situ formation of Δ9-THC from cannabidiol during GC-MS analysis

Gas chromatography-mass spectrometry (GC-MS) is widely used for the identification of cannabinoids in seized plant material. Conditions used for instrumental analysis should maximize decarboxylation, while minimizing the in situ production of Δ9-THC inside the GC inlet. In this study, decarboxylation of the acidic Δ9-THC precursor and in situ degradation of cannabidiol (CBD) were investigated using seven commercial GC liners with different deactivation chemistries and geometries. While the inlet temperature was previously optimized at 250°C in a previously validated assay, we systematically examined the temperature-dependent decarboxylation of tetrahydrocannabinolic acid-A (Δ9-THCA-A) and cyclization of CBD between 230°C and 310°C using different liners using favorable and unfavorable conditions. Significant differences in decarboxylation rate and CBD cyclization were observed between different liner types. While no temperature-dependent differences in decarboxylation rate were observed within liner type, liner-dependent differences were observed (α = 0.05), particularly between those with different geometry. In contrast, temperature and liner-dependent differences were observed for in situ formation of Δ9-THC (α = 0.05). This was influenced by liner geometry and to a smaller extent by surface deactivation. Effects were exacerbated with liner usage. While significant differences were observed using new and used GC liners, differences between liners of the same type but different lot numbers were not observed. Inter-instrument differences using the same liner were also evaluated and had minimal effect. Liner- and temperature-dependent effects were also confirmed using more than 20 cannabis plant extracts. Careful selection of liner, inlet conditions, and regular preventive maintenance can mitigate the risks associated with in situ formation Δ9-THC from CBD.

Differentiation of Δ9-THC and CBD Using Silver-Ligand Ion Complexation and Electrospray Ionization Tandem Mass Spectrometry (ESI-MS/MS)

The 2018 Farm Bill defines marijuana as Cannabis sativa L. or any derivative thereof that contains greater than 0.3% Δ9-tetrahydrocannabinol (Δ9-THC) on a dry weight basis. The main cannabinoids present in Cannabis sativa L., Δ9-THC and cannabidiol (CBD), are structural isomers that cannot be differentiated using direct mass spectrometry with soft ionization techniques alone. Due to the classification of marijuana as a Schedule I controlled substance, the differentiation of Δ9-THC and CBD is crucial within the seized drug community. This study explores the use of Ag-ligand ion complexation and electrospray ionization tandem mass spectrometry (ESI-MS/MS) for the differentiation of Δ9-THC and CBD using six different Ag complexes. Differences between the binding affinities of Δ9-THC and CBD for [Ag(PPh3)(OTf)]2 lead to the formation of unique product ions at m/z 421/423, m/z 353/355, and m/z 231 for CBD, enabling the differentiation of CBD from Δ9-THC. When applied to the analysis of known Δ9-THC:CBD mixture ratios, the developed [Ag(PPh3)(OTf)]2 ion complexation method was able to differentiate Δ9-THC-rich and CBD-rich samples based on the average abundance of the product ions at m/z 421/423. The developed approach was then applied to methanolic extracts of 20 authentic cannabis samples with known Δ9-THC and CBD compositions, resulting in a 95% correct classification rate. Even though the developed Ag-ligand ion complexation method was only demonstrated for the qualitative differentiation of Δ9-THC-rich and CBD-rich cannabis, this study establishes a foundation for the use of Ag-ligand ion complexation that is essential for future quantitative approaches.

Cannabigerol (CBG) signal enhancement in its analysis by gas chromatography coupled with tandem mass spectrometry

PURPOSE

According to recent reports, cannabigerol (CBG) concentration level in blood and body fluids may have forensic utility as a highly specific albeit insensitive biomarker of recent cannabis smoking. While the analytical sensitivity of cannabidiol (CBD), Δ9-tetrahydrocannabinol (Δ9-THC), cannabichromene (CBC) or cannabinol (CBN) estimation by gas chromatography-mass spectrometry (GC-MS) is similar and sufficiently high, it is exceptionally low in the case of CBG (ca. 25 times lower than for the other mentioned cannabinoids). The purpose of this study is to explain the reasons for the extremely low analytical sensitivity of GC-MS in estimating CBG and to present possible ways of its improvement.

METHODS

Nuclear magnetic resonance (NMR) data and GC-MS responses to CBG and its various derivatization and transformation products were studied.

RESULTS

The validation data of individual derivatives of CBG and its transformation products were established. CBG silylation/acylation or hydration allows to decrease LOD about 3 times, whereas the formation of pyranic CBG derivative leads to 10-times decrease of LOD. The paper enriches the literature of the subject by providing MS and NMR spectra, not published so far, for derivatives of CBG and its transformation products. The most likely cause of low GC-MS response to CBG is also presented.

CONCLUSIONS

The presented results shows that although the signal increase of CBG can be obtained through its derivatization by silylation and/or acylation, the greatest increase is observed in the case of its cyclization to the pyranic CBG form during the sample preparation process. The CBG cyclization procedure is very simple and workable in estimating this cannabinoid in blood/plasma samples.

The Therapeutic Potential and Molecular Mechanisms Underlying the Neuroprotective Effects of Sativex® - A Cannabis-derived Spray

Sativex is a cannabis-based medicine that comes in the form of an oromucosal spray. It contains equal amounts of Δ9-tetrahydrocannabinol and cannabidiol, two compounds derived from cannabis plants. Sativex has been shown to have positive effects on symptoms of amyotrophic lateral sclerosis (ALS), multiple sclerosis (MS), and sleep disorders. It also has analgesic, antiinflammatory, antitumoral, and neuroprotective properties, which make it a potential treatment option for other neurological disorders. The article reviews the results of recent preclinical and clinical studies that support the therapeutic potential of Sativex and the molecular mechanisms behind its neuroprotective benefits in various neurological disorders. The article also discusses the possible advantages and disadvantages of using Sativex as a neurotherapeutic agent, such as its safety, efficacy, availability, and legal status.

Application of gas chromatography in the analysis of phytocannabinoids: An update (2020-2023)

INTRODUCTION

Cannabinoids are a group of compounds that bind to cannabinoid receptors. They possess pharmacological properties like that of the plant Cannabis sativa. Gas chromatography (GC) is one of the popular chromatographic techniques that has been routinely used in the analysis of cannabinoids in different matrices.

OBJECTIVE

The article aims to review the literature on the application of GC-based analytical methods for the analysis of phytocannabinoids published during the period from January 2020 to August 2023.

METHODOLOGY

A thorough literature search was conducted using different databases, like Web of Knowledge, PubMed, Google Scholar, and other relevant published materials including published books. The keywords used, in various combinations, with cannabinoids being present in all combinations, in the search were cannabinoids, Cannabis sativa, marijuana, analysis, GC, quantitative, qualitative, and quality control. From the search results, only the publications that incorporate the GC analysis of phytocannabinoids were reviewed, and papers on synthetic cannabinoids were excluded.

RESULTS

Since the publication of the review article on GC analysis of phytocannabinoids in early 2020, several GC-based methods for the analysis of phytocannabinoids have appeared in the literature. While simple 1D GC-mass spectrometry (MS) and GC-flame ionisation detector (FID) methods are still quite common in phytocannabinoids analysis, 2D GC-MS and GC-MS/MS are increasingly becoming popular, as these techniques offer more useful data for identification and quantification of phytocannabinoids in various matrices. The use of automation in sample preparation and the utilisation of mathematical and computational models for optimisation of different protocols have become a norm in phytocannabinoids analysis. Pre-analyses have been found to incorporate different derivatisation techniques and environmentally friendly extraction protocols.

CONCLUSIONS

GC-based analysis of phytocannabinoids, especially using GC-MS, remains one of the most preferred methods for the analysis of these compounds. New derivatisation methods, ionisation techniques, mathematical models, and computational approaches for method optimisation have been introduced.

High Specific and Rapid Detection of Cannabidiol by Gold Nanoparticle-Based Paper Sensor

In order to facilitate monitoring of cannabidiol (CBD), we devised a gold immunochromatographic sensor based on a specific monoclonal antibody (mAb). To prepare the antigen, a novel hapten with CBD moiety and a linear carbon chain was employed. By utilizing hybridoma technology, a specific mAb was screened and identified that exhibited a 50% maximal inhibitory concentration against CBD ranging from 28.97 to 443.97 ng/mL. Extensive optimization led to the establishment of visual limits of detection for CBD, achieving a remarkable sensitivity of 8 μg/mL in the assay buffer. To showcase the accuracy and stability, an analysis of CBD-spiked wine, sparkling water, and sports drink was conducted. The recovery rates observed were as follows: 88.4-109.2% for wine, 89.9-107.8% for sparkling water, and 83.2-95.5% for sports drink. Furthermore, the coefficient of variation remained impressively low, less than 4.38% for wine, less than 2.07% for sparkling water, and less than 6.34% for sports drink. Importantly, the developed sensor exhibited no cross-reaction with tetrahydrocannabinol (THC). In conclusion, the proposed paper sensor, employing gold nanoparticles, offers a user-friendly and efficient approach for the precise, rapid, and dependable determination of CBD in products.

GC vs. HPLC in quantitation of CBD, CBG, ∆9-THC and CBN in plasma using different sample preparation methods

The sensitivity of complex analytical procedures depends not only on the sensitivity of the analytical instrument used, but also on the recovery degree of the examined analyte by the employed sample preparation method. The recovery degrees of individual cannabinoids reported in literature, estimated using the same sample preparation method, are unexpectedly divergent. Therefore, the aim of this study was a thorough assessment of the most commonly used sample preparation methods, such as protein precipitation, LLE, QuEChERS and SPE, in the context of the reliability of the obtained results. The presented report shows that the highest sensitivity, precision and reliability of the chromatographic analysis of CBG, CBD, ∆9-THC and CBN in human plasma can be obtained using SPE. The recovery degrees of these cannabinoids by SPE are highly repeatable and exceed 95 %, while they are significantly lower for such sample preparation methods as protein precipitation, LLE and QuEChERS (ca. 80, 65 and 87, respectively). Moreover, the supernatants obtained by the latter methods contain interferents evoking matrix-effect, which makes reliable quantification of the listed cannabinoids by GC difficult. To our knowledge, the paper is the first such extensive comparison of sample preparation procedures used for the determination of cannabinoids in plasma by GC-MS and HPLC-MS. The presented results and the discussion allow to understand why different recovery degrees for the same xenobiotic can be find in literature despite they have been estimated using the same or different sample preparation method or different chromatography types.

Unexpected formation of dichloroacetic and trichloroacetic artefacts in gas chromatograph injector during Cannabidiol analysis

The knowledge about the stability of compounds and possible ways of their transformation in the process of sample preparation for analysis and during analysis itself is very helpful in the assessment of possible errors which can appear when an accurate and precise estimation of compound concentration in tested samples is attempted. The present paper shows that a significant amount of CBD present in the blood/plasma sample analyzed by means of GC transforms in the hot GC injector not only to 9α-hydroxyhexahydrocannabinol, 8-hydroxy-iso-hexahydrocannabinol, Δ9-tetrahydrocannabinol, Δ8-tetrahydrocannabinol, and cannabinol but also to the trichloroacetic esters of Δ9-THC and Δ8-THC and, unexpectedly, to their dichloroacetic esters when trichloroacetic acid is used as protein precipitation agent. The increase of GC injector temperature favors the formation of dichloroacetic esters of Δ9-THC and Δ8-THC in relation to their trichloroacetic ones. The appearance of dichloroacetic esters of Δ9-THC and Δ8-THC among CBD transformation products is probably the result of the thermal decomposition of their trichloroacetic esters. The transformation of trichloroacetic derivatives of organic compounds into their dichloroacetic derivatives in GC injector has not been reported yet. The instability of trichloroacetic derivatives of Δ8-/Δ9-THC during their GC analysis is probably accounts for the lack of their GC-MS spectra in the databases. NMR, GC-MS and LC-MS spectra of the newly discovered derivatives constitute an important element of the work. The obtained results demonstrate why the use of trichloroacetic acid for plasma samples deproteinization should be avoided when CBD and/or THC are determined by GC.

Will tetrahydrocannabinol be formed from cannabidiol in gastric fluid? An in vivo experiment

Cannabidiol (CBD) products have ascribed an uprising trend for their health-promoting effects worldwide. In contrast to Δ⁹-tetrahydrocannabinol (THC), CBD exhibits no state of euphoria. Since conversion of CBD into THC in an acidic environment has been reported, it has not been proved whether this degradation will also occur in human gastric fluid. A total of 9 subjects ingested 400 mg CBD as a water-soluble liquid together with lecithin as an emulsifier and ethanol as a solubilizer. Blood samples were taken up to 4 h, and urine samples were submitted up to 48 h. THC, 11-hydroxy-Δ⁹-THC (THC-OH), 11-nor-9-carboxy-Δ⁹-THC (THC-COOH), CBD, 7-hydroxy cannabidiol (7-OH-CBD), and 7-carboxy cannabidiol (7-CBD-COOH) were determined in blood and THC-COOH and 7-CBD-COOH in urine by LC-MS/MS. Neither THC, THC-OH, nor THC-COOH were detectable in any serum specimen. Only two urine samples revealed THC-COOH values slightly above the threshold of 10 ng/ml, which could also be caused by trace amounts of THC being present in the CBD liquid. It can be concluded that negative consequences for participants of a drug testing program due to a conversion of CBD into THC in human gastric fluid appear unlikely, especially considering a single intake of dosages of less than 400 mg. Nevertheless, there is a reasonable risk for consumers of CBD products being tested positive for THC or THC metabolites. However, this is probably not caused by CBD cyclization into THC in human gastric fluid but is most likely due to THC being present as an impurity of CBD products.

Thermal decomposition of CBD to Δ9-THC during GC-MS analysis: A potential cause of Δ9-THC misidentification

On the analysis of cannabidiol (CBD) e-liquid by gas chromatography-mass spectrometry, we experienced suspected thermal decomposition of CBD to Δ⁹-tetrahydrocannabinol (Δ⁹-THC). To clarify the factors involved in the decomposition, we evaluated the effects of the injection methods (splitless or split), injector temperatures (250, 225, 200, and 180 °C), and liner conditions (new liner or used liner) on the CBD decomposition. We also examined whether addition of methylamine to the dissolving solvent (methanol) inhibited the decomposition. Decomposition was not observed under split mode. However, under splitless mode, we observed that decomposition was promoted with the use of used liner and by high injector temperatures, and addition of methylamine to the dissolving solvent also suppressed the decomposition. Split injection was effective for preventing the decomposition; however, splitless injection enables detection of lower-concentrated Δ⁹-THC in CBD products than split injection. To balance sensitivity of Δ⁹-THC and inhibition of the thermal decomposition under splitless mode, we recommend using new liner for the analysis, addition of methylamine to the dissolving solvent, and maintenance of the injector temperature at 200 °C.

Oleamide as analyte protectant in GC analysis of THC and its metabolites in blood

Methods for the analysis of cannabinoids in bio-matrices are continually being developed, to achieve a proper sensitivity required for their detection and accuracy in their quantification. The presented paper shows that the analytical sensitivity of GC-MS to THC and its metabolites in blood samples can be significantly increase by oleamide (OLA) addition to the examined sample, which evokes the matrix effect of transient character. The magnitude of signal increment resulting from oleamide presence in the examined sample is the greatest for THC metabolites and depends on oleamide concentration in the examined sample. The use of transient matrix effect to increase the sensitivity of the analysis can be applied not only in QuEChERS procedure, which is applied in the described experiments, but also in other blood sample preparation methods. Evoking the transient matrix effect by means of OLA in the experimental analytical quantitation of THC and its metabolites in blood allowed to lower limit of detection (LOD) approximately by 20.5%, 87.6% and 90.1% in the case of THC, THC-OH and THC-COOH, respectively.

Partitioning of phytocannabinoids between faeces and water - Implications for wastewater-based epidemiology

Evaluating consumption estimates for lipophilic drugs in wastewater has proven to be a challenge. A common feature for these compounds is that they are excreted in faeces and in conjugated form in urine. Limited research with no obvious experimental evidence has been conducted to investigate the degree to which faecal-bound chemical markers contribute towards mass loads in wastewater. Cannabis chemical markers, known as phytocannabinoids, have been suggested in literature to fall into this category. In this study, cannabis users (n = 9) and non-cannabis users (n = 5) were recruited and provided faecal and urine samples after using the substance. The common chemical markers of cannabis consumption, 11-nor-9-carboxy-Δ⁹-tetrahydrocannabinol (THC-COOH), 11-hydroxy-Δ⁹-tetrahydrocannabinol (THC-OH), Δ⁹-tetrahydrocannabinol (THC) and cannabidiol (CBD), were investigated. An extraction method was developed for the cannabis chemical markers in faecal matter and urine and analysis was performed by liquid chromatography-mass spectrometry. Participant samples were used to establish adsorption and desorption dissolution kinetics models and to assess the equilibrium between faeces and water for these compounds. Equilibration between phases were found to be fast (<5 min). THC-COOH, which is the primary metabolite used in wastewater studies, partitioned ~40% in water while the less polar metabolite and CBD remained largely associated with the particulate fraction. Faecal loads of both cannabis users and non-users affected the total measured amounts of cannabinoids in the aqueous phase. The implications for wastewater monitoring of lipophilic substances are discussed.

Improving the sensitivity of estimating CBD and other xenobiotics in plasma samples: Oleamide-induced transient matrix effect

The paper discusses the matrix effect evoked by oleamide (OLA), a compound frequently found in samples processed and/or stored in lab polypropylene vials or disposable syringes. In the case of many substances a higher response for their samples containing OLA than for net solutions is observed. The analyte signal gain resulting from OLA presence in the examined sample depends on the ratio of OLA concentration to analyte concentration. A characteristic feature of the matrix effect evoked by oleamide is its short duration, which makes the chromatographic data (retention value and signal magnitude of examined compound) repeatable and reproducible. The identified "transient matrix effect" may significantly increase the sensitivity of many analytical procedures employing GC. Evoking the transient matrix effect by means of OLA in the experimental analytical quantitation of cannabidiol in plasma allowed to lower its limit of detection (LOD) by more than 50 %.

A Critical Review of the Role of the Cannabinoid Compounds Δ9-Tetrahydrocannabinol (Δ9-THC) and Cannabidiol (CBD) and their Combination in Multiple Sclerosis Treatment

Many people with MS (pwMS) use unregulated cannabis or cannabis products to treat the symptoms associated with the disease. In line with this, Sativex, a synthetic combination of cannabidiol (CBD) and Δ⁹-tetrahydrocannabinol (Δ⁹-THC) has been approved to treat symptoms of spasticity. In animals, CBD is effective in reducing the amounts of T-cell infiltrates in the spinal cord, suggesting CBD has anti-inflammatory properties. By doing this, CBD has shown to delay symptom onset in animal models of multiple sclerosis and slow disease progression. Importantly, combinations of CBD and Δ⁹-THC appear more effective in treating animal models of multiple sclerosis. While CBD reduces the amounts of cell infiltrates in the spinal cord, Δ⁹-THC reduces scores of spasticity. In human studies, the results are less encouraging and conflict with the findings in animals. Drugs which deliver a combination of Δ⁹-THC and CBD in a 1:1 ratio appear to be only moderately effective in reducing spasticity scores, but appear to be almost as effective as current front-line treatments and cause less severe side effects than other treatments, such as baclofen (a GABA-B receptor agonist) and tizanidine (an α2 adrenergic receptor agonist). The findings of the studies reviewed suggest that cannabinoids may help treat neuropathic pain in pwMS as an add-on therapy to already established pain treatments. It is important to note that treatment with cannabinoid compounds may cause significant cognitive dysfunction. Long term double-blind placebo studies are greatly needed to further our understanding of the role of cannabinoids in multiple sclerosis treatment.

Are adverse effects of cannabidiol (CBD) products caused by tetrahydrocannabinol (THC) contamination?

Cannabidiol (CBD)-containing products are widely marketed as over the counter products, mostly as food supplements. Adverse effects reported in anecdotal consumer reports or during clinical studies were first assumed to be due to hydrolytic conversion of CBD to psychotropic Δ 9-tetrahydrocannabinol (Δ 9-THC) in the stomach after oral consumption. However, research of pure CBD solutions stored in simulated gastric juice or subjected to various storage conditions such as heat and light with specific liquid chromatographic/tandem mass spectrometric (LC/MS/MS) and ultra-high pressure liquid chromatographic/quadrupole time-of-flight mass spectrometric (UPLC-QTOF) analyses was unable to confirm THC formation. Another hypothesis for the adverse effects of CBD products may be residual Δ 9-THC concentrations in the products as contamination, because most of them are based on hemp extracts containing the full spectrum of cannabinoids besides CBD. Analyses of 293 food products of the German market (mostly CBD oils) confirmed this hypothesis: 28 products (10%) contained Δ 9-THC above the lowest observed adverse effect level (2.5 mg/day). Hence, it may be assumed that the adverse effects of some commercial CBD products are based on a low-dose effect of Δ 9-THC, with the safety of CBD itself currently being unclear with significant uncertainties regarding possible liver and reproductive toxicity. The safety, efficacy and purity of commercial CBD products is highly questionable, and all of the products in our sample collection showed various non-conformities to European food law such as unsafe Δ 9-THC levels, hemp extracts or CBD isolates as non-approved novel food ingredients, non-approved health claims, and deficits in mandatory food labelling requirements. In view of the growing market for such lifestyle products, the effectiveness of the instrument of food business operators' own responsibility for product safety and regulatory compliance must obviously be challenged, and a strong regulatory framework for hemp products needs to be devised.

Are adverse effects of cannabidiol (CBD) products caused by tetrahydrocannabinol (THC) contamination?

Cannabidiol (CBD)-containing products are widely marketed as over the counter products, mostly as food supplements. Adverse effects reported in anecdotal consumer reports or during clinical studies were first assumed to be due to hydrolytic conversion of CBD to psychotropic Δ ⁹-tetrahydrocannabinol (Δ ⁹-THC) in the stomach after oral consumption. However, research of pure CBD solutions stored in simulated gastric juice or subjected to various storage conditions such as heat and light with specific liquid chromatographic/tandem mass spectrometric (LC/MS/MS) and ultra-high pressure liquid chromatographic/quadrupole time-of-flight mass spectrometric (UPLC-QTOF) analyses was unable to confirm THC formation. Another hypothesis for the  adverse effects of CBD products may be residual Δ ⁹-THC concentrations in the products as contamination, because most of them are based on hemp extracts containing the full spectrum of cannabinoids besides CBD. Analyses of 181 food products of the German market (mostly CBD oils) confirmed this hypothesis: 21 products (12%) contained Δ ⁹-THC above the lowest observed adverse effect level (2.5 mg/day). Inversely, CBD was present in the products below the no observed adverse effect level. Hence, it may be assumed that the adverse effects of some commercial CBD products are based on a low-dose effect of Δ ⁹-THC and not due to effects of CBD itself. The safety, efficacy and purity of commercial CBD products is highly questionable, and all of the products in our sample collection showed various non-conformities to European food law such as unsafe Δ ⁹-THC levels, hemp extracts or CBD isolates as non-approved novel food ingredients, non-approved health claims, and deficits in mandatory food labelling requirements. In view of the growing market for such lifestyle products, the effectiveness of the instrument of food business operators' own responsibility for product safety and regulatory compliance must obviously be challenged, and a strong regulatory framework for hemp products needs to be devised.

Are side effects of cannabidiol (CBD) products caused by tetrahydrocannabinol (THC) contamination?

Cannabidiol (CBD)-containing products are widely marketed as over the counter products, mostly as food supplements, to avoid the strict rules of medicinal products. Side-effects reported in anecdotal consumer reports or during clinical studies were first assumed to be due to hydrolytic conversion of CBD to psychotropic Δ 9-tetrahydrocannabinol (Δ 9-THC) in the stomach after oral consumption. However, research of pure CBD solutions stored in simulated gastric juice or subjected to various storage conditions such as heat and light with specific liquid chromatographic/tandem mass spectrometric (LC/MS/MS) and ultra-high pressure liquid chromatographic/quadrupole time-of-flight mass spectrometric (UPLC-QTOF) analyses was unable to confirm THC formation. Another hypothesis for the side-effects of CBD products may be residual Δ 9-THC concentrations in the products as contamination, because most of them are based on crude hemp extracts containing the full spectrum of cannabinoids besides CBD. Analyses of 67 food products of the German market (mostly CBD oils) confirmed this hypothesis: 17 products (25%) contained Δ 9-THC above the lowest observed adverse effects level (2.5 mg/day). Inversely, CBD was present in the products below the no observed adverse effect level. Hence, it may be assumed that the adverse effects of some commercial CBD products are based on a low-dose effect of Δ 9-THC and not due to effects of CBD itself. The safety, efficacy and purity of commercial CBD products is highly questionable, and all of the products in our sample collection showed various non-conformities to European food law such as unsafe Δ 9-THC levels, full-spectrum hemp extracts as non-approved novel food ingredients, non-approved health claims, and deficits in mandatory food labelling requirements. In view of the growing market for such lifestyle products, the effectiveness of the instrument of food business operators' own responsibility for product safety must obviously be challenged.

Are adverse effects of cannabidiol (CBD) products caused by tetrahydrocannabinol (THC) contamination?

Cannabidiol (CBD)-containing products are widely marketed as over the counter products. Adverse effects reported in anecdotal consumer reports or during clinical studies were first assumed to be due to acid-catalysed cyclization of CBD to psychotropic Δ 9-tetrahydrocannabinol (Δ 9-THC) in the stomach after oral consumption. However, research of pure CBD solutions stored in simulated gastric juice or subjected to various storage conditions such as heat and light with specific liquid chromatographic/tandem mass spectrometric (LC/MS/MS) and ultra-high pressure liquid chromatographic/quadrupole time-of-flight mass spectrometric (UPLC-QTOF) analyses was unable to confirm THC formation. Another hypothesis for the adverse effects of CBD products may be residual Δ 9-THC concentrations in the products as contamination, because most of them are based on hemp extracts containing the full spectrum of cannabinoids besides CBD. Analyses of 413 hemp-based products of the German market (mostly CBD oils) confirmed this hypothesis: 48 products (12%) contained Δ 9-THC above the lowest observed adverse effect level (2.5 mg/day). Hence, it may be assumed that the adverse effects of some commercial CBD products are based on a low-dose effect of Δ 9-THC, with the safety of CBD itself currently being unclear with significant uncertainties regarding possible liver and reproductive toxicity. The safety, efficacy and purity of commercial CBD products is highly questionable, and all of the products in our sample collection showed various non-conformities to European food law such as unsafe Δ 9-THC levels, hemp extracts or CBD isolates as non-approved novel food ingredients, non-approved health claims, and deficits in mandatory food labelling requirements. In view of the growing market for such lifestyle products, the effectiveness of the instrument of food business operators' own responsibility for product safety and regulatory compliance must obviously be challenged, and a strong regulatory framework for hemp products needs to be devised.

Are adverse effects of cannabidiol (CBD) products caused by tetrahydrocannabinol (THC) contamination?

Cannabidiol (CBD)-containing products are widely marketed as over the counter products, mostly as food supplements. Adverse effects reported in anecdotal consumer reports or during clinical studies were first assumed to be due to hydrolytic conversion of CBD to psychotropic Δ 9-tetrahydrocannabinol (Δ 9-THC) in the stomach after oral consumption. However, research of pure CBD solutions stored in simulated gastric juice or subjected to various storage conditions such as heat and light with specific liquid chromatographic/tandem mass spectrometric (LC/MS/MS) and ultra-high pressure liquid chromatographic/quadrupole time-of-flight mass spectrometric (UPLC-QTOF) analyses was unable to confirm THC formation. Another hypothesis for the  adverse effects of CBD products may be residual Δ 9-THC concentrations in the products as contamination, because most of them are based on hemp extracts containing the full spectrum of cannabinoids besides CBD. Analyses of 181 food products of the German market (mostly CBD oils) confirmed this hypothesis: 21 products (12%) contained Δ 9-THC above the lowest observed adverse effect level (2.5 mg/day). Inversely, CBD was present in the products below the no observed adverse effect level. Hence, it may be assumed that the adverse effects of some commercial CBD products are based on a low-dose effect of Δ 9-THC and not due to effects of CBD itself. The safety, efficacy and purity of commercial CBD products is highly questionable, and all of the products in our sample collection showed various non-conformities to European food law such as unsafe Δ 9-THC levels, hemp extracts or CBD isolates as non-approved novel food ingredients, non-approved health claims, and deficits in mandatory food labelling requirements. In view of the growing market for such lifestyle products, the effectiveness of the instrument of food business operators' own responsibility for product safety and regulatory compliance must obviously be challenged, and a strong regulatory framework for hemp products needs to be devised.

Are adverse effects of cannabidiol (CBD) products caused by tetrahydrocannabinol (THC) contamination?

Cannabidiol (CBD)-containing products are widely marketed as over the counter products, mostly as food supplements. Adverse effects reported in anecdotal consumer reports or during clinical studies were first assumed to be due to acid-catalysed cyclization of CBD to psychotropic Δ 9tetrahydrocannabinol (Δ 9-THC) in the stomach after oral consumption. However, research of pure CBD solutions stored in simulated gastric juice or subjected to various storage conditions such as heat and light with specific liquid chromatographic/tandem mass spectrometric (LC/MS/MS) and ultra-high pressure liquid chromatographic/quadrupole time-of-flight mass spectrometric (UPLC-QTOF) analyses was unable to confirm THC formation. Another hypothesis for the adverse effects of CBD products may be residual Δ 9-THC concentrations in the products as contamination, because most of them are based on hemp extracts containing the full spectrum of cannabinoids besides CBD. Analyses of 362 hemp-based products of the German market (mostly CBD oils) confirmed this hypothesis: 39 products (11%) contained Δ 9-THC above the lowest observed adverse effect level (2.5 mg/day). Hence, it may be assumed that the adverse effects of some commercial CBD products are based on a low-dose effect of Δ 9-THC, with the safety of CBD itself currently being unclear with significant uncertainties regarding possible liver and reproductive toxicity. The safety, efficacy and purity of commercial CBD products is highly questionable, and all of the products in our sample collection showed various non-conformities to European food law such as unsafe Δ 9-THC levels, hemp extracts or CBD isolates as non-approved novel food ingredients, non-approved health claims, and deficits in mandatory food labelling requirements. In view of the growing market for such lifestyle products, the effectiveness of the instrument of food business operators' own responsibility for product safety and regulatory compliance must obviously be challenged, and a strong regulatory framework for hemp products needs to be devised.