Some antidepressants can lower testosterone, but the effect depends heavily on which type you take. SSRIs, the most commonly prescribed class, are the most likely to interfere with testosterone production through their effect on serotonin and prolactin. Other types, like bupropion and mirtazapine, appear to have little or no impact on testosterone levels.
How SSRIs Affect Testosterone
SSRIs work by increasing serotonin activity in the brain. That extra serotonin does more than improve mood. It also stimulates the release of prolactin, a hormone normally associated with milk production. SSRIs, older tricyclic antidepressants, and MAO inhibitors can all cause modest increases in prolactin levels through this serotonin-driven pathway.
Higher prolactin disrupts the hormonal chain that controls testosterone production. Normally, your brain sends signals (via hormones called gonadotropins) to the testes or ovaries to produce sex hormones. Elevated prolactin blunts those signals, which leads to decreased testosterone and estrogen production. This is the primary mechanism behind the sexual side effects so many people experience on SSRIs: lower libido, difficulty with arousal, and trouble reaching orgasm. Serotonin may also interfere with testosterone through more direct pathways that are less well understood.
The prolactin increase from antidepressants is typically described as “modest and generally asymptomatic,” meaning it often doesn’t rise high enough to cause obvious hormonal symptoms on its own. But even subclinical shifts in prolactin can be enough to nudge testosterone downward, particularly in people whose levels were already on the lower end.
SNRIs and Tricyclics
SNRIs like duloxetine add norepinephrine reuptake inhibition on top of serotonin effects, which raises the question of whether they hit testosterone harder than SSRIs alone. The available evidence suggests they don’t. A randomized controlled trial of duloxetine in men found no clinically meaningful effects on serum hormones after six weeks of treatment. Hormonal values also returned to baseline after discontinuation. This was the first published human study of an SNRI’s effect on male fertility hormones, and the researchers concluded that duloxetine, and possibly other SNRIs, may be reasonable options for men concerned about hormonal effects.
Tricyclic antidepressants with strong serotonin activity can raise prolactin through the same mechanism as SSRIs. Those with less serotonergic action are less likely to affect prolactin or testosterone meaningfully, though tricyclics are prescribed far less frequently today.
Antidepressants Less Likely to Affect Testosterone
Not all antidepressants carry the same hormonal risk. Bupropion (sold as Wellbutrin) works on dopamine and norepinephrine rather than serotonin, so it skips the prolactin-raising mechanism entirely. In a randomized, double-blind trial, men taking bupropion saw modest improvements in total plasma testosterone from baseline. However, the placebo group also improved, and the difference between the two groups was not statistically significant. The takeaway: bupropion doesn’t appear to suppress testosterone, and it may offer a slight boost, though the evidence for that is weak.
Mirtazapine is another option with a more favorable hormonal profile. It enhances serotonin and norepinephrine release but directs serotonin toward specific receptor subtypes that don’t trigger the prolactin surge. This results in antidepressant effects with fewer sexual side effects. Vortioxetine, a newer antidepressant with a complex receptor profile, also shows significantly fewer sexual side effects compared to traditional SSRIs. In a head-to-head trial, vortioxetine at 10 mg caused meaningfully fewer sexual side effects than paroxetine, with a statistically significant difference. A separate study found that patients switched from SSRIs to vortioxetine saw significant improvements in desire, arousal, and orgasm compared to those switched to escitalopram.
The Sexual Side Effect Connection
If you’re searching this question, there’s a good chance you’re experiencing sexual side effects on an antidepressant and wondering whether testosterone is the reason. The relationship is real but not as straightforward as “low T causes the problem.” SSRI-related sexual dysfunction involves multiple overlapping mechanisms: elevated serotonin directly dampens arousal pathways, prolactin suppresses reproductive hormones, and dopamine signaling (which drives desire) gets crowded out by excess serotonin activity. Testosterone changes are one piece of a larger puzzle.
This matters because simply checking a testosterone level and finding it “within normal range” doesn’t rule out a hormonal contribution. The normal range for testosterone is wide, and a drop from the upper end to the lower end, while still technically normal, can be enough to affect libido and sexual function. If you’re experiencing these side effects, the medication class itself is the most actionable variable to discuss with your prescriber.
Do Levels Recover After Stopping?
For most people, yes. The hormonal disruption from antidepressants appears to be reversible. In the duloxetine trial, hormone levels returned to baseline within a few weeks of stopping the medication. A retrospective study of men with persistent sexual symptoms after stopping SSRIs found that their sexual hormone profiles, including testosterone, were within normal ranges at the time of assessment. This suggests that even when sexual side effects linger after discontinuation (a condition sometimes called post-SSRI sexual dysfunction), the cause is likely neurological rather than hormonal. The brain’s serotonin receptors and sensitivity may take longer to recalibrate than the endocrine system does.
What This Means Practically
If you’re on an SSRI and concerned about testosterone, you have a few options worth discussing with your prescriber. Switching to an antidepressant with a different mechanism, such as bupropion, mirtazapine, or vortioxetine, is one of the most studied strategies for reducing sexual side effects while maintaining antidepressant effectiveness. A dose reduction, when clinically appropriate, can also reduce prolactin-driven hormonal changes since the effect is generally dose-dependent.
Getting a baseline testosterone level before starting an antidepressant, or at least early in treatment, gives you a reference point. A follow-up test a few months in can reveal whether a meaningful drop has occurred. This is especially relevant for men over 40, who may already be experiencing age-related testosterone decline and are more likely to notice the compounding effect of a medication that further suppresses it.