We don’t talk enough about sperm. Male reproductive cells rarely come up in everyday conversation (of course, it’s not a topic for the family dinner table with Grandma, but it definitely should be addressed with the seriousness it deserves), and as a result, men rarely dare to open up about it with their doctors.
Is it taboo, ignorance, or just laziness? Lack of commitment, neglect, or plain disdain? Whatever the case, from a biological standpoint, it’s a truly important topic. Especially when there’s a desire for fatherhood. From there, some fundamental questions arise: Is there any correlation between cannabis and sperm? For instance, is there any difference between CBD and THC effects? Could weed change sperm count? We’ve got your attention now, right?
Let’s start with the basics: there’s a biological mechanism by which cannabinoids, like THC and CBD, can interact with the male reproductive system, namely the CB1 and CB2 receptors. Because of these receptors, which act on the male reproductive tract, including the testicles and sperm, both THC and CBD seem to alter Sertoli cells, which are responsible for providing structural and metabolic support during spermatogenesis (the process of sperm formation and maturation).
“Sertoli cells are the ‘nurse cells’ of the testicle,” explains Lex Pelger, a science communicator in the cannabis world, author of the newsletter Cannabinoids & the People, and host of not one, but two YouTube channels: CV Sciences and Cannabinoids & the People by Lex Pelger. “CBD and THC inhibit CatSper ion channels, which are necessary for more vigorous swimming, thus reducing the sperm’s ability to penetrate the egg. There are also some preclinical studies suggesting that cannabinoids modify the epigenetics of sperm production, leading to lower sperm quality,” he continues.
To support this point, he cites a scientific article by researchers at the University of Oxford that claims that “THC and CBD reduced the effectiveness of human sperm by inhibiting CatSper channels” and that “major phytocannabinoids” affect “the function of CatSper calcium channels.”
However, the evidence is not conclusive, as he cites a preclinical evaluation published in Reproductive Toxicology, which states that “in rat fertility models, low doses of cannabis did not affect male fertility. While in females there were hormonal alterations, there were no changes in reproductive cycles or implantation.”
In that regard, Pelger notes that current studies present “mixed evidence,” but, importantly, “there is a reasonable amount of data reporting associations with lower sperm count, reduced motility, and, most frequently reported, poorer morphology.”
However, there is also evidence regarding CBD and its possible “protective action” thanks to its anti-inflammatory and antioxidant properties. For instance, this scientific article in Toxicology Letters presents all the nuances. Pelger’s point concerns the administration and intensity of weed use. And it makes sense: more intense (or chronic) users tend to show “greater reductions in sperm concentration.”
This issue can be extrapolated to any other area of life: there is a relationship between dose and impact. Yes, also in sperm parameters. Let’s not play dumb: you don’t have to be a genius to figure it out. Occasional or regulated use can have mild, negligible, or controlled effects. And what about chronic cases? Therein lies the dilemma…
“(With chronic use) sperm tend to exhibit lower DNA quality, reduced chromatin integrity (how tightly the DNA is packaged within the sperm head), as well as reduced capacitation (the preparation process that happens once the sperm enters the female reproductive tract),” the science communicator asserts.
Therefore, in the pursuit of conception, medicine and pharmacology recommend a “washout” or “cleansing” period of about 2 to 3 months, which is the duration of the spermatogenesis cycle. Here, Pelger cites a scientific study from Fertility and Sterility that states that the “damage” from THC is not “permanent” and that “periods of abstinence” have “a real and measurable impact on reproductive health.”
Meanwhile, Pelger finds no difference in the biological impact of administration methods (smoking, vaping, or ingesting), but rather—once again—it depends on the quantity used, not how it got there. “I suppose the toxic byproducts of combustion from smoking wouldn’t help, but I doubt that’s a major factor,” he clarifies. It’s true: the smoke from combustion is harmful on its own, and its negative effect doesn’t come directly from THC and its interaction with receptors. “In fact, the evidence for tobacco and its significant impact on male fertility is very strong,” he adds.
He also points to strong evidence for obesity and excessive alcohol consumption. “In general, although cannabis does seem to negatively impact male fertility, this isn’t found in all studies, which probably means the effect isn’t that strong overall,” the science communicator explains. The recommendation, if you’re having trouble conceiving, is that “both partners stop using cannabis” to “avoid potentially hindering fertility.”
Balance and context. Detox, vigor, and freedom. The key is understanding how our bodies work. Cannabis is neither a contraceptive nor a death sentence. So, if the plan is to bring someone into the world, it’s worth remembering that sperm operate under a cycle of constant renewal. Ultimately, it’s about managing weed use with the same intelligence you use to choose your favorite strains: knowing when to increase your pace and when to slow down so your “swimmers” can reach the finish line.
Photo by Deon Black on Unsplash
