Trazodone does not appear to lower testosterone. The limited research available actually points in the opposite direction: animal studies show testosterone levels increasing with trazodone use, not decreasing. However, the drug does affect other hormones and reproductive functions in ways worth understanding if you’re concerned about your hormonal health.
What the Research Shows About Testosterone
The most direct evidence comes from a study published in Oxidative Medicine and Cellular Longevity that measured testosterone levels in rats given trazodone at three different doses over 28 days. All three dose groups had significantly higher testosterone levels than the control group. The control animals averaged a testosterone level of 2.53, while treated groups ranged from 3.40 to 3.84, representing roughly a 34% to 52% increase. Importantly, the testosterone levels didn’t differ much between the low, medium, and high dose groups, suggesting even smaller amounts had this effect.
There’s a major caveat here: this was an animal study, and the results can’t be directly translated to humans. No large-scale clinical trials have specifically measured testosterone levels in people taking trazodone. The FDA’s prescribing information for trazodone does not list low testosterone or any testosterone-related change as a known side effect. So while there’s no evidence trazodone lowers testosterone, the honest answer is that the question hasn’t been rigorously studied in humans.
Trazodone Does Raise Prolactin
One hormonal effect that has been confirmed in humans is a rise in prolactin. A study of 12 depressed patients taking 150 mg of trazodone at bedtime found that average prolactin levels jumped from 9.1 to 14.7 ng/ml within 12 hours of the first dose. Levels remained elevated at one and two weeks before partially settling by week three.
This matters because prolactin and testosterone have an inverse relationship. When prolactin stays high for extended periods (a condition called hyperprolactinemia), it can suppress the hormonal signaling chain that tells your body to produce testosterone. The prolactin increase seen with trazodone was relatively modest, though, and may not be large enough to meaningfully suppress testosterone in most people. This is likely why the animal data showed testosterone going up despite the drug’s prolactin-raising tendency. The mechanism behind the prolactin increase involves a trazodone byproduct that activates serotonin receptors, which in turn stimulates prolactin release from the pituitary gland.
How Trazodone Compares to Other Antidepressants
If you’re weighing trazodone against other antidepressants for sexual and hormonal side effects, trazodone generally comes out ahead. A randomized controlled trial comparing trazodone to fluoxetine (Prozac) and sertraline (Zoloft) found that trazodone caused the fewest sexual problems across the board. Only 12% to 18% of men on trazodone reported reduced desire or drive, compared to 43% to 51% on fluoxetine. Arousal and orgasm problems affected just 9% to 15% of men on trazodone versus significantly higher rates on the other two drugs. Sertraline fell in the middle.
Sexual dysfunction from SSRIs is often linked to hormonal disruption, including changes in testosterone and prolactin. The fact that trazodone causes fewer of these problems is indirect but meaningful evidence that its hormonal impact is milder than that of more commonly prescribed antidepressants.
Reproductive Side Effects That Are Known
While testosterone suppression isn’t a documented concern, trazodone does have some notable reproductive side effects. The most well-known is priapism, a prolonged, painful erection lasting more than six hours. This is considered rare, occurring in fewer than 1% of men, with estimates ranging from 1 in 1,000 to 1 in 10,000 users. A study of 229 patients found that about 8% experienced prolonged erections, but none required emergency treatment. The mechanism isn’t hormonal. It’s caused by trazodone blocking certain receptors in blood vessel walls that normally allow an erection to subside, reducing local blood flow control in the penis.
Other uncommon reproductive side effects reported in FDA postmarketing data include breast enlargement, lactation (linked to that prolactin increase), and retrograde ejaculation. Clinical trials also noted impotence and changes in libido at rates below 2%.
Low Dose for Sleep vs. Full Antidepressant Dose
Many people take trazodone at low doses (25 to 100 mg) for insomnia rather than the full antidepressant dose of 250 to 600 mg per day. The animal research showed that testosterone increases were similar across all dose levels tested, which suggests the hormonal effect isn’t strongly dose-dependent. But again, translating animal doses to human doses is imprecise, and no human studies have specifically compared hormonal effects at sleep-aid doses versus antidepressant doses.
If you’re taking a low dose for sleep and wondering whether it’s affecting your testosterone, the current evidence gives no reason to think it would lower levels. The more likely scenario, based on available data, is that trazodone either has no meaningful effect on testosterone or a mildly positive one. That said, if you’re experiencing symptoms like fatigue, low libido, or mood changes and suspect a hormonal issue, getting your levels tested is straightforward and would give you a definitive answer rather than relying on limited research.