Drug transfer during intimate moments: A key issue in doping control that can be documented by hair tests of the athlete and the partner

As it is the case for the general population, amateur and professional athletes can be exposed to a specific drug by environmental factors. This has been suggested by Thevis et al., ¹ under the concept of athlete exposome. Part of this situation is due to the development of very sensitive instruments that can be coupled to ultra-specific detectors, such as high-resolution mass spectrometry. Indeed, laboratories are now able to measure drugs in urine at the pg/mL level with suitable accuracy. As a consequence, it has been observed in the last period of time an increasing number of adverse analytical findings (AAF) during doping controls, with estimated drug concentration close or even much lower than 1 ng/mL. These AAF are generally vigorously challenged by the athletes, claiming that the findings correspond to a scenario of contamination and not to an anti-doping rules violation (ADRV).

A low or a very low urine concentration can be interpreted in two different ways: 1. it can be the tail end of a drug used to enhance performance; or 2. it is the direct consequence of a contamination. By contamination, one can include laced supplements ² either voluntarily or by lack of hygiene measures, contaminated meat by growth promoters, ³ mostly beef, pork, and poultry, poor quality pharmaceuticals ⁴ with chemical residues and finally drug transfer during intimate moments. ⁵ This last type of contamination is presented by journalists as the “kissing defence” or the “sex defence”.

In the last years, several athletes have been cleared from their ADRV advocating drug transfer during intimate moments. This was the case, for example, for Richard Gasquet with cocaine, ⁶ Shawnacy Barber with cocaine, ⁷ Gil Roberts with probenecid, ⁸ Madilyn Nickles with ligandrol, ⁹ Virginia Fuchs with letrozole and GW1516, ¹⁰ Laurence Vincent–Lapointe with ligandrol ¹¹ or Dayana Yastremska with mesterolone. ¹²

In all these cases, after the ADRV had been notified, a ban (period of ineligibility where the athlete is not allowed to compete) was imposed on the athlete. As the athletes denied cheating and taking prohibited substances, they appointed a legal team to look after their defence. In the World anti-doping code, ¹³ it is indicated that if someone establishes in an individual case that the athlete bears no fault or negligence, the otherwise applicable period of ineligibility shall be eliminated. The task of the legal representative, as per the rules of the code to satisfy the no fault or negligence, was to address the following points: 1. the athlete must present verified circumstances of contamination; 2. the source of contamination must be clearly identified; 3. the athlete must demonstrate that the violation was not intentional (the athlete did not knowingly take the controlled substance).

In addition to the rules of the Code to account for no fault or negligence, it is the opinion of the author, based on a previous strategy, ¹⁴ that the scenario of the “sex defence” should be consistent with: 1. the estimated urine concentration must be very low in comparison with what can be measured after using a pharmacologically active dose of the prohibited substance; 2. a segmental hair test result of the athlete must demonstrate that exposure to the prohibited substance was incidental; 3. the legal team of the athlete must present a valid scenario of drug transfer during intimate moments; 4. the source of contamination (the partner) must be identified and be presented during the hearing; 5. a segmental hair test result of the partner must demonstrate exposure to the corresponding prohibited substance.

In the experience of the author, when these 5 items are not met, a suitable final decision (no period of ineligibility) remains very difficult to obtain. Two points are very critical, i.e., point 3 and point 4. Indeed, very little has been published about possible drug transfer during intimate moments. In their paper about athlete exposome, Thevis et al. ¹ have identified 3 human tissues that can account for drug transfer during intimate contact. These tissues are skin, saliva, and seminal fluid. There is no need for the athlete to become in contact with a large dose of a prohibited substance, as, for example, it has been demonstrated that a single 1 µg oral dose of ostarine, a selected androgen receptors modulator, can be detected for up to 9 days in urine. ¹⁵ Several other micro-dosing studies have been published in the scientific literature.

Indeed, this is one of the key points. Given the lack of suitable reference studies in the literature, it is very complicated to consider in practice the amounts of drugs which can reasonably be transferred during different sexual practices which span from local contamination of the genital area to inadverted internal intake of amounts of drugs suitable for causing a positive drug test in urine. There is no need for a transfer of a large dose of doping agent. In addition to what has been published ¹⁵ about ostarine (detection for several days in urine of a single 1 µg oral dose), other studies have confirmed that a single 1 µg dose of ligandrol ¹⁶ or RAD140 ¹⁷ are detectable over several days in urine. The pharmacologically active doses of these oral selective androgen receptor modulators, controlled under section S1.2 (other anabolic agents) by the World Anti-Doping Agency (WADA) are in the range 10 to 30 mg per day. It is possible that a 1000 (10 µg) or even 10000 (1 µg) time lower dose can be transferred during kissing via oral fluid contamination. It has been published ¹⁸ that a single dose of 1.87 mg of cocaine can be detected in urine for about 2 days. This amount represents a fraction of what can be sniffed and can correspond to some remains close to the lips of a cocaine abuser. Doping cases have been claimed to be due to cocaine transfer during intensive kissing with a partner having recently sniffed the drug, for example, Shawn Barber. ¹⁹

In 2004, ⁵ Pereira et al. demonstrated that clostebol, an anabolic steroid, can be transferred during sexual intercourse. The authors identified the metabolite of clostebol in the urine of 2 men (0.9 to 3.5 ng/mL) having sex for about 20 min with 2 separate women immediately after intra-vaginal application of the drug. The concept of skin transfer of clostebol was confirmed later by de la Torre et al. ²⁰ They indicated that after application of 5 mg of clostebol in her hand, a woman was able to transfer the drug to six from seven volunteers just by hand shaking, with metabolite urine concentrations of 0.1 to 0.5 ng/mL, several hours after the contact. The World anti-doping agency is perfectly aware about possible skin transfer, as a strong statement ²¹ about the “very limited” risk of contamination and therefore an ADRV, for example for sabotage, was published after a 2021 documentary by German broadcaster ARD.

Oral fluid or saliva has a potential role in anti-doping testing as most of drugs can be identified in this matrix ²² although some WADA prohibited substances, such as SARMs have never been reported. One of the biggest advantages of oral fluid testing versus urine testing is for cannabis, as the presence of Δ9-tetrahydrocannabinol will unambiguously document recent smoking and potential impairment. This demonstrates that oral fluid contains active agents. Therefore, transmission by kissing of drug-contaminated saliva from one person to another is undeniable. The frequency and intensity of kissing will determine the dosage of drug the other person will be exposed. For example, cocaine intake, even inadvertent, is more likely to occur due to traces of the substance remaining in the partner's oral cavity or the region of the lips after snorting, rather than by ingestion of “drug-contaminated saliva”, where transfer from the blood lead to low concentrations of cocaine and metabolites.

However, this is very complicated to demonstrate as such study must include verification of the drug dosage of the partner, the route of administration and, of course, the delay between intake and kissing. In most cases, for a specific drug involved in an ADRV, literature is missing. Therefore, it is not possible to rely on a published controlled study with suitable pharmacokinetic parameters after a micro-dose. Uncompleted data, such as a single measure in urine can be deterrent for the athlete to establish the moment of last exposure and one should encourage active scientists to perform investigations in oral fluid, as this specimen is probably a future standard in drug detection, given its non-invasive collection and potential correlation with what is circulating in blood.

The case of Richard Gasquet is typical of oral fluid contamination. ⁶ About 150 ng/mL of benzoylecgonine and minute amounts of parent cocaine were identified in his urine. His segmental hair test was negative. The source of contamination was perfectly identified, i.e., a young lady with whom the athlete shared several kisses some hours before the urine control. He did not know that she used cocaine some minutes before the first kiss. Her hair test results revealed repetitive abuse of cocaine. All the proposed criteria proposed above have been met.

If oral fluid drug transfer is difficult to firmly establish, it is even more complicated with seminal fluid. A very limited number of drugs have been identified in semen. ²³ This did not prevent the claim of three female athletes of inadvertent doping due to the semen from a partner using a prohibited substance.^9–11 Some details of the case of Laurence Vincent–Lapointe with ligandrol have been shared in a recent publication. ²⁴ However, the presence of prohibited substances and their concentrations in seminal fluid remain highly speculative. This is mostly due to the inaccessibility of semen for frequent collection over a short period of time in order to achieve measurements of drug concentrations that are requested to establish sound pharmacokinetic parameters. At this time, due to a lack of data, drug concentrations in seminal fluid remain speculative.

In addition, in an attempt to demonstrate possible contamination, it has been recently published that semen specimens can contain a drug present in urine left in the urethra at the time of ejaculation. ²⁵

The key point of this defence strategy is the hair test result. These days, the author has noticed that all successful outcomes have involved hair tests, and even, in some cases, the hearing panel has requested one when it was missing. First, the hair test of the athlete allows confirming any deny of doping practices. A negative hair test or very low concentrations due to repetitive contaminations can strengthen the accuracy of the claims of the athlete. Almost all doping substances but hormones are detectable in hair. ²⁶ Hair tests can provide additional elements to document drug exposure as the analysis of this matrix increases the window of drug detection and permits the discrimination of a single exposure from long-term use when doing segmental analyses. In case head hair specimen is missing (bald subject) or cannot be collected for religious reasons, body hair ²⁷ or nail clippings ²⁸ can be collected.

Limitations or pitfalls of hair analysis have been extensively reviewed, in general cases ²⁹ and in the case of doping investigations.^30,31 For a limited number of drugs (mostly drugs of abuse), the minimal detectable dose in hair has been established. For example, it is known that a single recreative dose of cocaine, amphetamine, ecstasy, or codeine is detectable in hair. ³² This has also been demonstrated for a few prohibited substances, such as letrozole. ³³ However, a single dose of some drugs is not detectable in hair. For example, the administration of a single tablet of hydrochlorothiazide, a diuretic, is not detectable in hair. ³⁴ However, it is possible to have a balance between high and low concentrations in hair for less studied drugs, such as diuretics or ß-adrenergic drugs when reviewing the existing literature. Indeed, concentrations after long-term use, for example, for therapeutic purposes are available.^34–36 Scientists still do not know what can or cannot be detected in human hair when it comes to SARMs or anabolic steroids. A negative hair result can be interpreted in three different ways: 1. the donor did not use the drug; 2. the analytical procedure of the laboratory is not sensitive enough to detect the drug; or 3. an event, such as cosmetic treatment or environmental influence (UV, chlorinated or salty water, adulterant products) happened after drug incorporation. ³⁷

However, if the measured concentrations in the various hair segments of the athlete, covering the period of the urine control, correspond to repetitive active doses, one can immediately exclude a scenario of drug transfer during intimate moments. Indeed, high hair concentrations are not consistent with incidental exposure(s).

It is accepted that for some drugs, for example for anabolic steroids, occasional transfer of minute amounts will not be detectable in hair. This is a highly positive property of a hair test, as it will discriminate long-term abuse (presence of the drug in hair), needed to get a pharmacological effect from an incidental exposure (absence of the drug in hair), rendering viable the scenario of contamination during drug transfer.

Once the prerequisite of a negative athlete's hair test result has been validated, it is mandatory to identify the source of contamination, i.e., the partner using the prohibited substance. There must be strong evidence that the athlete and the partner do have an affair, as a lack of such a proof can have major consequences on the final outcome of the case. For example, the panel did not accept the claims of an athlete as she was not able to provide contemporaneous evidence about the relationship between her and her partner, including photographs, telephone calls, texts, messages, or receipts from restaurants. ³⁸ The partner has to accept to see his/her name be involved in the procedure. The circumstances of drug transfer must be properly established. At this stage, to corroborate the claims of drug transfer, a hair test must be performed on the partner in order to demonstrate personal use of the prohibited substance. This is a critical point as sometimes there is a refusal to submit a hair specimen. For various privacy reasons listed previously, the lack of such evidence will dramatically reduce the probability of lifting the sanctions. It is mandatory, as per the anti-doping code, to establish the source of contamination. Again, the segmental hair test must cover the period of the urine control.

In the cases the author was involved, the athlete did not know that his/her partner was abusing prohibited substances, or at least claimed he/she was not aware of such behaviour. In most instances, this resulted in a separation.

When dealing with privacy, and the “sex defence” is typically involving privacy, it can be complicated to obtain accurate details of the case. Given the context, the initial claims are generally underreported and minimised. Once the possible consequences are known (for example 4 years of ineligibility, loss of employment or sponsors), additional details can be provided. Even, sometimes, a totally new version of the facts is presented. This is a situation that is not well accepted by sport authorities. The “in deep” version can have numerous private consequences, such as couple fighting, couple breakdown, involvement of a third person (lover) or divorce with family and financial outcomes. The athlete can be afraid of media scandal or does not want to implicate his/her partner, particularly when the partner is unlawful. Finally, in a case of LGBT subjects, this can have incredible importance as coming out and sport have complicated relationship.

According to the rules of the anti-doping code, ¹³ the athlete must be aware of his/her responsibility of what is entering in his/her body. However, the code has anticipated possible situations where this strict liability can be taken into default. Some sport authorities have accepted the concept of drug transfer during intimate moments as noticed in recent decisions. However, all these decisions have returned favourably because the legal team produced at the hearing a complete package including the circumstances of drug transfer, the source of contamination and of course, valid hair test results. This can appear as a sort of prerequisite.

In conclusion, the author can accept that this viewpoint article may be considered biased in favour of the accused athletes. This is acknowledged, but on the other hand, doping controls are under the responsibility of WADA with tests performed in accredited laboratories. The author does not participate to the control of the athletes but can only act for the defence as a part of the legal team in charge of their interests. Although the situation of contamination of penis by drugs applied in vagina or on vulva is totally different from the hypothesis of internal “contamination” by drug transfer by a kiss, it has been scientifically demonstrated that drug transfer during intimate contacts is possible. Once this has been established, the probability of this occurred in a particular case is based on the following facts: low or even very low concentration of the analyte or its metabolite(s) detected in urine during the control, absence or minimal concentration of the parent drug in hair, identification of the source (the partner consuming the doping agent), presence of the analyte in the hair of the partner at concentrations in accordance with repetitive use. This protocol will put the legal team of the athlete in the best situation towards the Court of Arbitration for Sports (CAS) in Lausanne and the author has produced in reference several cases. In addition, several decisions from USADA (United States anti-doping agency) or panels from international federations have also accepted these hypotheses. In the end, it is the Tribunal that decides that drug transfer during intimate moments is probable.

Finally, the author can accept that the definitive contamination scenario by drug transfer suffers from the paucity of experimental literature. In particular, it is not possible, at this stage, to address quantitative considerations. Indeed, to resolve this issue, only controlled studies can definitively validate the concept of drug transfer. However, I am not aware of any report dealing with drug consumption by subject 1 and subsequent urine measurement in subject 2 after kissing or sexual relationship. Nevertheless, administration of drugs in a micro-dose of 1−10 µg,^15–17 which obviously can be in the range of what is present in oral fluid or semen, has resulted in detectable amounts in urine for several days. This also allows the crossing of “possible” to “probable” for drug transfer during intimate moments.

This research received no specific grant from any funding agency in the public, commercial, or not-for-profit sectors.