Unauthorized ingredients in "nootropic" dietary supplements: A review of the history, pharmacology, prevalence, international regulations, and potential as doping agents

Heptaminol hair testing to highlight octodrine contamination in supplements, responsible for a doping adverse analytical finding

Octodrine, also known as dimethylhexylamine (DMHA), is a central nervous stimulant. When ingested by humans, octodrine is rapidly metabolized to heptaminol, the main compound present in the blood. Due to their stimulant activities, octodrine and its metabolite are specified substances in section S6b "specified stimulants" of the World Anti-Doping Agency (WADA) Prohibited List, prohibited in competition. But in some cases, they can be responsible for an adverse analytical finding (AAF) following contamination, with a low concentration in the urine. In such cases, a hair test can distinguish doping from contamination according to the concentration measured, or the absence of the target drug. However, no data are available in the literature. The aim of this study was to develop a liquid chromatography-tandem mass spectrometry (LC-MS/MS) method for the quantification of octodrine and heptaminol in hair, and to apply it to an athlete with an AAF with heptaminol (141 and 136 ng/mL in urine samples A and B after correction for specific gravity) and octodrine (16 ng/mL, not given by the WADA laboratory in sample A as being below the minimum request level of 50 ng/mL). All the supplements taken by the athlete were analysed, and pubic hair (black, 1.5-2 cm long, no head hair available) and toenail clippings (0.1 cm) were sampled two months after AAF. A supplement was identified as the source of contamination, containing octodrine at a concentration range 16-34 µg/g. The athlete had taken 13 g daily (0.2-0.4 mg octodrine) for 20 days prior to the AAF (total dose 4-8 mg). His pubic hair and toenail clippings contained only heptaminol (30 pg/mg and 3 pg/mg, respectively). A controlled study was carried out on a volunteer who took a single 13 g dose of the contaminated supplement (single dose of octodrine 0.2-0.4 mg). His urine was positive for both compounds, with concentrations very close to those of the athlete on the day of the AAF after the same delay between intake and sampling (around 4 h). One month later, his head hair and pubic hair showed only heptaminol at 2 and 3 pg/mg, respectively, and toenail clippings were totally negative for both compounds. The contamination was accepted by the WADA commission, but the athlete was still banned for 9 months for having consumed supplements purchased on the internet.

Mexidol, Cytoflavin, and succinic acid derivatives as antihypoxic, anti-ischemic metabolic modulators, and ergogenic aids in athletes and consideration of their potential as performance enhancing drugs

Emoxypine (ethylmethylhydroxypyridine) is a synthetic derivative of vitamin B6. Emoxypine succinate is a registered drug in Russia and Ukraine under various trade names including Mexidol, Mexicor, and Armadin Long. Mexidol demonstrates antihypoxic and anti-ischemic effects and also modulates metabolism. The use of Mexidol by Russian athletes has been confirmed in the past. Current use by athletes is unknown as this drug is not monitored or included in drug testing protocol. Metabotropic and antihypoxic effects of Mexidol were compared to the effects of meldonium or trimetazidine, both of which are included on the World Anti-Doping Agency (WADA) Prohibited List in category S4.4. Metabolic Modulators. The conjugation of emoxypine with succinate elevates the therapeutic effectiveness of the Mexidol formulation as succinic acid itself has important impacts to consider despite being a common food additive and drug excipient. Other succinic acid salts like ammonium succinate, found as dietary supplement, have been patented as performance enhancers. Available research on healthy subjects suggests that combinations of selected 3-substituted pyridine derivatives with succinate including Mexidol and a related drug Cytoflavin can enhance the performance of athletes. Cytoflavin is a multi-component formula containing meglumine sodium succinate, nicotinamide (vitamin B3), inosine (riboxin), and riboflavin. Other related succinate-based drugs include Remaxol, Reamberin, and Cogitum. Mexidol and Cytoflavin and related substances exhibit similar biological effects as drugs on the WADA Prohibited List, and if they are used for performance enhancement by athletes, they could be worthy of consideration as prohibited substances in sport.

Purchasing "Nootropics" Online: Identification and Quantification of Ingredients in Phenibut-Containing Products

Background and Objectives: Phenibut is a central nervous system drug that is registered and used in clinical practice as a prescription medication. In recent decades, the drug has become popular as a "nootropic and cognition enhancer" because of its active marketing as a dietary or food supplement sold online. This has resulted in a growing number of case reports on acute toxicity and withdrawal symptoms and has raised concerns about the quality of phenibut-containing products. Materials and Methods: We used high-performance liquid chromatography with diode-array detection and ultra-performance liquid chromatography-mass spectrometry to investigate the quality of six phenibut-containing samples purchased from three internet suppliers. Results: Substantially lower levels of the active pharmaceutical ingredient than claimed on the packaging were found for three of the supplements tested. A considerably higher level of phenibut was present in one product. All online-purchased phenibut-containing capsules included declared and undeclared ingredients found in various dietary supplements claiming to have metabolic, neurotropic, antioxidant, anti-inflammatory, and neuroprotective properties. Conclusions: The online-purchased phenibut products contained undeclared ingredients and the content of phenibut differed from the declared. The combinations of these additional ingredients with phenibut have not been tested for activity or safety and their use warrants further attention to avoid potential health problems.

Acute Treatment with the Nootropic CILTEP® Does Not Improve Cognitive Performance in Healthy Middle-Aged Participants

This study investigated the acute effects of the dietary nootropic stack CILTEP®. It contains a combination of ingredients that have been individually reported to improve cognitive performance. Especially, the ingredients luteolin, which is considered a phosphodiesterase type 4 (PDE4) inhibitor, and forskolin, an adenylate cyclase stimulator, were of interest since they can increase the second messenger cAMP and thus also intracellular signaling. Numerous studies have shown that inhibition of PDE4 can improve memory in animals and humans. We examined whether acute dosing of 3 capsules of CILTEP® would improve cognitive function in healthy participants aged 30 to 40 (n = 33). We used a randomized, double-blind, placebo-controlled, two-way cross-over design. Our test battery was aimed at measuring memory performance, attention, and sensorimotor speed. The primary outcome measures were the performance on the verbal learning task and the spatial pattern separation task. Secondary outcomes included other cognitive tests, event-related potentials (ERPs), and assessment of the activity of the enzyme beta-glucuronidase and its effect on the bioavailability of luteolin, heart rate, and blood pressure. No relevant effects of acute CILTEP® treatment were found on any measure of the test battery or ERPs. Blood plasma concentrations of luteolin increased, yet about 2000 times too low to likely exert any PDE4 inhibition. CILTEP® treatment did neither affect heart rate nor blood pressure. In summary, there is no evidence that a single standardized dose of 3 capsules of CILTEP® can improve cognitive function in healthy middle-aged participants.

Determination of chlorphenesin in cosmetics, a preservative that can affect anti-doping test result interpretations

Chlorphenesin is a legitimate preservative commonly used in cosmetics. It shares one urinary metabolite of 4-chlorophenoxyacetic acid with meclofenoxate, a prohibited stimulant in sports. Recently, there have been cases where athletes using chlorphenesin-containing products were falsely identified as users of meclofenoxate. This study developed and validated a liquid chromatography method with diode-array detection to determine the chlorphenesin content in 61 selected personal care products with various functions (e.g., facial care, body cleansing, sun protection, make-up, hairstyling, perfume, and oral cleaning). The analytical method demonstrated fit-for-purpose quantitation and provided good linearity, precision, accuracy, and recovery for analyzing different cosmetic matrices. Among the 27 cosmetics labeled with chlorphenesin, the chlorphenesin concentrations ranged from 0.10 to 2.67 mg/g, with three products showing no detection. None of the products exceeded the maximum limit of 3 mg/g (0.3%) set by regulatory authorities. Among the 34 cosmetics not labeled with chlorphenesin, none of them contained chlorphenesin. This study confirmed the absence of undeclared chlorphenesin in the selected cosmetics, supporting the correctness of chlorphenesin labeling in cosmetics sold in Taiwan. Further investigations studying urinary excretion patterns after different types, doses, frequencies, and sites of cosmetics applications could contribute to strengthen current testing approaches in anti-doping.

Phenibutan—an Illegal Food Supplement With Psychotropic Effects and Health Risks

BACKGROUND

Phenibut (β-phenyl-γ-aminobutyric acid) is an analog of the neurotransmitter gamma-aminobutyric acid (GABA). Like abapentin and pregabalin, it inhibits α2-δ-subunits of voltagedependent presynaptic calcium channels. The potential harm resulting from the use of these gabapentinoids is currently a matter of debate.

METHODS

This review is based on pertinent publications retrieved by a selective literature search and on cases reported to the Giftinformationszentrum-Nord (GIZ-Nord), a poison information center at the University of Göttingen, Germany.

RESULTS

Phenibut is a prescription drug in Russia but its production, possession, use, trafficking, or administration is illegal in Germany. The phenibut toxicity syndrome resembles that of gabapentinoids and GABA mimetics: benzodiazepine-like with - drawal symptoms including epileptic seizures, delirium and paradoxical activation have been described, as have cases of abuse and dependence. A few cases of use in the setting of multidrug abuse, and of phenibut-related death, have been described to date in the USA. The GIZ-Nord received 17 inquiries about phenibut, 55 about gabapentin, and 126 about pregabalin over the period 2008-2022. Over the same period, the GIZ-Nord was informed of 1207 cases involving Z substances and 4324 involving benzodiazepines. In the majority of the registered intoxications, including those with phenibut, the symptoms were mild. Overdoses of phenibut (2-100 g) were reported in 15 of the 17 cases; 8 of the persons who had taken an overdose were somnolent. In such cases, observation in intensive care was recommended. Respiratory depression or coma was not encountered in any case, not even in the patient who had taken 100 g of phenibut.

CONCLUSION

Phenibut causes symptoms resembling those of gabapentinoid and benzodiazepine use. There have been reports of phenibut use in combination with other psychotropic drugs; in particular, its use together with opiates could increase the risk of coma and respiratory depression. No deaths due to phenibut intoxication have been published in Germany or elsewhere in Western Europe, although such cases may have been overlooked, as this drug is still largely unknown to Western medicine.

Recent advances in mass spectrometry for the detection of doping

INTRODUCTION

The analysis of doping control samples is preferably performed by mass spectrometry, because obtained results meet the highest analytical standards and ensure an impressive degree of reliability. The advancement in mass spectrometry and all its associated technologies thus allow for continuous improvements in doping control analysis.

AREAS COVERED

Modern mass spectrometric systems have reached a status of increased sensitivity, robustness, and specificity within the last decade. The improved sensitivity in particular has, on the other hand, also led to the detection of drug residues that were attributable to scenarios where the prohibited substances were not administered consciously but rather by the unconscious ingestion of or exposure to contaminated products. These scenarios and their doubtless clarification represent a great challenge. Here, too, modern MS systems and their applications can provide good insights in the interpretation of dose-related metabolism of prohibited substances. In addition to the development of new instruments itself, software-assisted analysis of the sometimes highly complex data is playing an increasingly important role and facilitating the work of doping control laboratories.

EXPERT OPINION

The sensitive analysis and evaluation of a higher number of samples in a shorter time is made possible by the ongoing developments in mass spectrometry.

Annual banned-substance review 16th edition-Analytical approaches in human sports drug testing 2022/2023

In this 16th edition of the annual banned-substance review on analytical approaches in human sports drug testing, literature on recent developments in this particular section of global anti-doping efforts that was published between October 2022 and September 2023 is summarized and discussed. Most recent additions to the continuously growing portfolio of doping control analytical approaches and investigations into analytical challenges in the context of adverse analytical findings are presented, taking into account existing as well as emerging challenges in anti-doping, with specific focus on substances and methods of doping recognized in the World Anti-Doping Agency's 2023 Prohibited List. As in previous years, focus is put particularly on new or enhanced analytical options in human doping controls, appreciating the exigence and core mission of anti-doping and, equally, the conflict arising from the opposingly trending extent of the athlete's exposome and the sensitivity of instruments nowadays commonly available in anti-doping laboratories.