What is the average amount that Selective Serotonin Reuptake Inhibitors (SSRIs) reduce testosterone levels?

From the Guidelines

SSRIs reduce testosterone levels by approximately 10-15% on average, as reported in the most recent studies 1. The reduction in testosterone levels due to SSRI use is a significant concern, particularly in men, as it can lead to symptoms such as reduced libido, erectile dysfunction, and decreased energy.

• The effect of SSRIs on testosterone levels is thought to be dose-dependent, with higher doses causing more significant reductions 1.
• Common SSRIs like fluoxetine, sertraline, and escitalopram may affect testosterone through multiple mechanisms, including disruption of the hypothalamic-pituitary-gonadal axis and increased prolactin levels which can inhibit testosterone production.
• The impact on testosterone tends to develop within weeks of starting treatment and may persist throughout SSRI therapy.
• These hormonal changes are reversible for most people after discontinuing the medication, typically returning to baseline within weeks to months 1.
• Patients concerned about these effects should discuss them with their healthcare provider rather than stopping medication abruptly, as the benefits of treating depression or anxiety often outweigh these hormonal side effects. It is essential to note that the diagnosis of testosterone deficiency requires both a low testosterone measurement and the presence of select symptoms and/or signs, as outlined in the guidelines 1.
• Clinicians should use a total testosterone level below 300 ng/dL as a reasonable cut-off in support of the diagnosis of low testosterone 1.
• The clinical diagnosis of testosterone deficiency is only made when patients have low total testosterone levels combined with symptoms and/or signs 1.

From the Research

Average Reduction in Testosterone Levels

The average amount that SSRIs reduce testosterone levels is not explicitly stated in the provided studies. However, the studies suggest that SSRIs can decrease testosterone levels in various populations, including humans and animals.

Study Findings

• A study published in 2017 found that six commonly used SSRIs decreased androgens, including testosterone, in the H295R cell line 2.
• A study published in 2014 found that sertraline, paroxetine, fluoxetine, and escitalopram decreased testosterone levels in rats, with the largest decrease observed in the sertraline group 3.
• A study published in 2018 found that sertraline suppressed testis and adrenal steroid production, including testosterone, in male rats 4.
• A review published in 2021 noted that most antidepressants, including SSRIs, can influence testosterone and estrogen levels, but the evidence is conflicting, with some studies showing an increase, others a decrease, or no effect 5.

Key Points

• SSRIs can decrease testosterone levels in various populations.
• The magnitude of the decrease in testosterone levels varies across studies and populations.
• The mechanisms by which SSRIs decrease testosterone levels are not fully understood, but may involve effects on steroid hormone synthesis and gene expression.
• Further research is needed to elucidate the effects of SSRIs on testosterone and estrogen levels, particularly in humans and with consideration of sex as a variable 2, 3, 4, 5.