From the Guidelines
Smoking one joint of marijuana per week is unlikely to significantly impact male fertility for most men. According to the American Urological Association (AUA) and the American Society for Reproductive Medicine (ASRM) guideline part I, published in 2021 1, there is low-quality evidence for some association between lifestyle factors, including smoking, and male infertility. While the guideline does not specifically address marijuana use, it mentions that smoking has a small impact on sperm concentration, motility, and morphology. However, it is essential to note that the evidence is limited, and more research is needed to fully understand the effects of marijuana on male fertility.
When considering the potential impact of marijuana on fertility, it is crucial to look at the overall lifestyle and health of the individual. The AUA/ASRM guideline highlights that men with abnormal semen parameters have higher rates of testicular cancer and mortality rates, emphasizing the importance of addressing underlying health issues 1. Additionally, advanced paternal age has been linked to increased de novo intra- and inter-genic germline mutations, sperm aneuploidy, and other genetic risks in offspring, which may be a more significant concern than occasional marijuana use 1.
Some key points to consider:
- Occasional, light marijuana use may have minimal effects on sperm parameters
- Heavier or more frequent marijuana use can negatively impact sperm count, morphology, and motility
- Individual responses to marijuana can vary based on factors like overall health, genetics, and lifestyle habits
- Men with pre-existing fertility issues should be cautious about any marijuana use
- Abstaining from marijuana for at least three months before conception attempts may be prudent, especially for those experiencing fertility challenges, as sperm development takes approximately 74 days 1.
From the Research
Effects of Cannabis on Male Fertility
- The use of cannabis, particularly among men of reproductive age, has been linked to potential negative impacts on male fertility 2, 3, 4.
- Studies have shown that cannabis use can affect semen parameters, including reduced sperm count and concentration, abnormalities in sperm morphology, reduced sperm motility and viability, and inhibited capacitation and fertilizing capacity 4.
- The endocannabinoid system plays a crucial role in regulating male reproduction, and disturbing this balance through cannabis use can have negative effects on reproductive potential 2, 3.
Frequency of Cannabis Use and Male Fertility
- While the exact frequency of cannabis use that can affect male fertility is not specified, studies suggest that any amount of cannabis use can have potential negative impacts on reproductive health 5.
- A study on the effects of cannabis use on reproductive health found that preconception cannabis use was associated with reduced fecundability among women, but the impact on male fertility was not directly assessed 6.
- However, another study found that cannabis use was associated with reduced sperm count, motility, and viability, suggesting that even occasional use, such as 1 joint per week, could potentially affect male fertility 4.
Mechanisms of Cannabis-Induced Effects on Male Fertility
- The exact mechanisms by which cannabis use affects male fertility are not fully understood, but it is thought that the psychoactive compound THC interferes with the hypothalamic-pituitary-gonadal axis, leading to changes in hormone levels and sperm function 3, 4.
- THC has been shown to decrease gonadotropin-releasing hormone (GnRH) secretion, which can lead to changes in testosterone levels and sperm production 3.
- Further research is needed to fully understand the effects of cannabis use on male fertility and to determine the potential risks associated with different frequencies and amounts of use 4, 5.