According to data from OECD (Organisation for Economic Co-operation and Development), the UK has the highest rate of Cocaine use in Europe and is only 2nd worldwide to Australia.
Partly driven by a binge drinking culture, around 3% of 15 – 64 yr olds have used or are using cocaine. Use amongst men tends to be higher than in women with a ratio of approximately 4:1.
Cocaine is a powerful and addictive drug that derives from the leaves of the Coca plant (Erythroxylum coca) and is known to alter the structure and function of the brain if used repeatedly. For thousands of years, people in South America have chewed the leaves for cultural and medicinal reasons to suppress hunger, tiredness or to alleviate altitude sickness as they increase oxygen absorption in the body. The purified chemical, cocaine hydrochloride, was then isolated from the plant over 100 years ago.
Elevating feelings of euphoria, confidence and helping people feel awake and energised pure cocaine is as a go to drug for many people on a night out and is often used alongside alcohol and other drugs such as tobacco and marijuana. The side effects, however, are not quite so pleasant. Restlessness, irritability, anxiety, paranoia, and insomnia being just a few with some serious long-term consequences associated with the heart and circulatory system.
So, do these side effects reach as far as fertility? Well, we took a look at the research.
The use of cocaine amongst men trying to conceive seems to be quite low, potentially as low as 1%. Research in this area is hard to complete due to the illicit nature of the drug but also because many cocaine users will also be taking other illicit drugs and perhaps not living the healthiest of lifestyles. With only 1 human study, other research has looked at the impact of cocaine on the sperm and testicles of mice or rats.
Cocaine’s effect on the body
Cocaine has a strong stimulating effect on the nervous system and causes a release of dopamine in the brain. Dopamine is responsible for making us feel good and works as a reward mechanism giving us feelings of pleasure or euphoria. Since our brains are wired to seek out activities that create this feeling, this is why cocaine is so addictive. At “normal” levels, dopamine plays a key role in regulating many of our bodily functions including movement, alertness, and energy. However, in higher doses its effects on the body become less beneficial causing narrowing of blood vessels (vasoconstriction), thus increasing in blood pressure and other physiological effects often associated with the “fight or flight” response.
So, what affect does this have on fertility?
Testicular blood supply
Vasoconstriction associated with higher doses of cocaine use has been shown to impact the blood supply to the testicles. One study on rats found that high doses of cocaine given by injection caused a significant change in the blood supply to the testicles which was potentially associated with other testicular changes including decreased spermatogenesis, changes to the seminiferous tubes, cell death and abnormal cells. It was concluded that cocaine use could lead to cellular death of the testicles in humans.
Hormonal changes
Part of the response to the huge rise in dopamine from cocaine is an increase in norepinephrine levels. Norepinephrine, also known as noradrenaline, is a stress hormone and neurotransmitter that is produced in the adrenal glands and the nervous system from dopamine by means of an enzyme called dopaminhydroxylase. It is one of the main hormones at play during the “fight or flight” response, designed to get us ready to deal with highly stressful situations where we need to respond quickly to protect our lives.
It is this hormone that is responsible for making us more alert, constricting blood vessels, increasing our heart rate, increasing blood pressure, dumping sugar into the blood supply for more energy and basically making us ready to fight whatever comes our way. By nature, this is designed to be an acute short-term response to get us out of danger. However, we are not designed to be in this state for a long period of time. Prolonged cocaine use puts an undue strain on our kidneys, adrenal glands, heart, lungs, liver, and brain and has been associated with heart disease, Parkinson’s disease, respiratory illnesses, and stroke, to name just a few.
In terms of the hormones that are directly involved in sperm production, Luteinising hormone (LH), testosterone and Follicle Stimulating Hormone (FSH), cocaine has been shown to have a direct impact.
LH is responsible for triggering the production of testosterone. Low levels of cocaine have been shown to increase LH and subsequently increase testosterone levels. FSH, another key hormone, is responsible for triggering spermatogenesis and is finely balanced and partly controlled by testosterone levels as part of a negative feedback loop to the pituitary gland and the brain. Artificially raised testosterone levels from the use of cocaine (and any other anabolic steroid abuse for that matter) will reduce FSH levels, thus decreasing sperm production. Further use of cocaine or its use in higher doses has been shown to inhibit the release of LH which subsequently decreases testosterone levels which will further impact sperm quality.
Our hormones and sperm production are a finely balanced process with hormones being the master controllers. Any slight change in those hormones because of external inputs will undoubtedly impact sperm production and ultimately lower sperm quality.
One study we reviewed looked at sperm quality amongst men who had reported cocaine use in the 2 years prior to their semen analysis. This single published human study demonstrated that cocaine use was associated with a sperm concentration of less than 20 million per millilitre. Men with sperm counts less than 20 million per millilitre were two times more likely to have used cocaine within the past 2 years than men who had not used cocaine.
Although the number of studies on cocaine use and fertility in men is limited, almost all studies on the use of illicit drugs show negative effects on different parts of the male reproductive system which can result in subfertility or complete infertility amongst users.
Long term damage
Apart from the associated long-term risks associated with cocaine use discussed above there is some minor good news amongst these studies. Research has shown that relatively low doses of cocaine are not likely to have a significant effect on sperm quality although some effect is still noted, mainly reduced motility. Some research has shown that these changes are short term with normal sperm quality returning after drug use has stopped. As is often the case, it seems to be about dosage and duration of use that is key to the significance of the impacts of such drugs. However, as cocaine use often goes hand in hand with other less healthy lifestyle habits, it is quite likely that a man’s fertility will be impacted by a mixture of elements.
Summary
In summary, the evidence around cocaine and male fertility is limited. There are very few human studies on the impact of cocaine on men but there is some evidence that should make men think very carefully about using recreational drugs such as cocaine.
There is enough evidence to show that high dosage and long-term use could have serious consequences on fertility, testicular health, and general long-term health.
If any man has been a long-time user of recreational drugs, then stopping those drugs and getting properly assessed is imperative. This could include hormonal blood tests as well as comprehensive male fertility assessments.
Many drugs such as cocaine are highly addictive and stopping is not always as easy as people may think. If you need support, then you should discuss this with your GP.
Research reviewed
Bracken MB, Eskenazi B, Sachse K, McSharry JE, Hellenbrand K, Leo-Summers L (1990); Association of cocaine use with sperm concentration, motility, and morphology. Fertil Steril 53: 315-322
Nazmara Z, Ebrahimi B, Makhdoumi P, Noori L, Mahdavi SA, Hassanzadeh G (2021); Effects of illicit drugs on structural and functional impairment of testis, endocrinal disorders, and molecular alterations of the semen. Iran J Basic Med Sci 24: 856-867
Belladelli F, Boeri L, Capogrosso P, Cazzaniga W, Ventimiglia E, Candela L, Pozzi E, Baudo A, Alfano M, Abbate C, Montorsi F, Salonia A (2021); Substances of abuse consumption among patients seeking medical help for uro-andrological purposes: a sociobehavioral survey in the real-life scenario. Asian J Androl 23: 456-461
Fronczak CM, Kim ED, Barqawi AB (2012); The insults of illicit drug use on male fertility. J Androl 33: 515-528