The short answer
Cannabis is legal for adults in California, and many men use it regularly without thinking much about hormones. When they do ask, the question is usually blunt: is it lowering my testosterone or hurting my erections?
The research gives three different answers to three different questions. For testosterone, the human data are mixed and mostly reassuring. For sperm, studies disagree with each other, with the strongest warning sign in frequent users. For erections, the signal is the most consistent of the three, especially with heavy use. That split is worth understanding before you decide what, if anything, to test.
Does cannabis lower testosterone?
Not reliably, according to the larger human studies. The strongest U.S. data come from the national NHANES survey. In a 2017 analysis of 1,577 men measured by mass spectrometry, testosterone was essentially identical in men who had ever used marijuana and men who never had, with adjusted means of 3.69 and 3.70 ng/mL. Recency mattered more than frequency or duration: men who had used more recently tended to have slightly higher levels, particularly those aged 18 to 29.
A Danish study of 1,215 young men pointed the same direction. In that 2015 study, men who smoked marijuana had higher testosterone, in the same range seen in cigarette smokers. A 2021 meta-analysis pooling hormone data from 4,787 men found no significant difference in testosterone between users and non-users, though FSH was slightly lower in users.
One recent study adds a caution. A 2025 analysis of U.S. insurance records, which compared men diagnosed with cannabis abuse or dependence against carefully matched controls, found a higher rate of new testosterone deficiency diagnoses in the first year in the cannabis group, 0.2% against 0.1%. That study captured heavy, problem use through diagnosis codes rather than everyday use, and the absolute numbers were small.
| Question | What the studies show | How confident |
|---|---|---|
| Does regular use lower testosterone? | No consistent drop; some studies show slightly higher levels | Moderate |
| Does heavy, problem use change the picture? | One large records study found more testosterone deficiency diagnoses | Low to moderate |
| Does cannabis affect sperm? | Studies conflict; the harm signal is strongest above weekly use | Low |
| Is cannabis linked to erectile dysfunction? | Yes, in most studies, especially with heavy use | Moderate |
What about sperm?
This is where the research genuinely disagrees. The Danish study found that men who smoked marijuana more than once a week had about 28% lower sperm concentration and 29% lower total sperm count than non-users, and that combining weekly marijuana with other recreational drugs cut both by more than half.
Other studies have not confirmed it. The 2021 meta-analysis found no statistically significant increase in abnormal semen results among users. A 2025 North American cohort of 921 men trying to conceive found that current cannabis use was not appreciably associated with semen quality, though weekly or more frequent use was loosely associated with low semen volume.
So the honest summary is uncertainty, with the most concerning data in men who use frequently. If you and your partner are trying for a pregnancy, that uncertainty is a reason to cut back and to test rather than assume. Our page for men trying to conceive covers the wider workup.
Erections: the most consistent signal
The erection data line up better. A 2019 meta-analysis of five studies with 3,395 men found erectile dysfunction in 69.1% of cannabis users against 34.7% of controls, with users having almost four times the odds of ED. The authors flagged high variation between studies and called for longer-term research, but the direction was clear.
The 2025 records study, led by a team in Los Angeles, found the same pattern on a larger scale. Among about 29,000 matched pairs of men, a diagnosis of cannabis abuse or dependence was linked to roughly four times the risk of a new ED diagnosis in the following year, 0.9% against 0.2%, and to more ED medication use. The link was smaller but still present three to five years later.
Why might that happen when testosterone looks normal? Possible explanations include effects on blood vessels, anxiety and arousal, and the overlap between heavy cannabis use and smoking, alcohol, poor sleep and depression. None of the studies can prove cause and effect. Our page on ED in men under 40 explains how those factors are sorted out.
What a regular user should actually test
If you use cannabis regularly and feel fine, there is no special cannabis panel you need. If you have symptoms, the testing follows the symptom, not the plant.
- Low libido, fatigue or fewer morning erections: two early-morning total testosterone tests, with free testosterone and SHBG if the result is borderline. Our page on the total testosterone blood test explains timing.
- Erection problems: blood sugar, lipids and testosterone, since ED can be an early sign of vascular disease; see blood tests for erectile dysfunction.
- Trying to conceive: a semen analysis, plus testosterone, LH and FSH.
- You smoke rather than use edibles: mention it, because smoke exposure matters for heart and lung health and for some lab results.
Questions worth bringing to the visit
- Could my cannabis use explain this symptom, or is something else more likely?
- Should my testosterone be repeated before we draw any conclusion?
- If I cut back, when would a retest tell us something useful?
- Does how I use it, smoked, vaped or edible, change anything for my heart or lungs?
- Are any of my other medicines affected by regular cannabis use?
Be specific with your provider about how often you use, how much and in what form. Clinicians are not there to judge, and a vague “sometimes” makes results harder to interpret. If you are already on testosterone therapy, our page on cannabis on TRT covers what to know.
How Ultimate Male approaches it
At our San Gabriel and Downey clinics, cannabis use is simply part of your history, recorded alongside alcohol, sleep and medicines. Through our preventative blood testing, labs are drawn on site, results come back in 24 to 48 hours, and the TRT pre-screening panel covers total testosterone, estradiol, PSA and a complete blood count.
A PA-C or MD reads those numbers with your symptoms and habits in mind. If your testosterone is normal and the problem is erections, the conversation moves to vascular health and ED options rather than hormones. If you want to start that conversation, call 626-319-5261 for the free 10-minute phone call.
