Abstract
BACKGROUND: Vitamin B12 plays a key role in the serotonergic pathway; we predicted that B12 replacement could be beneficial in the treatment of premature ejaculation (PE) in patients with B12 deficiency. We aimed to investigate the response to vitamin B12 replacement in PE patients with vitamin B12 deficiency. METHODS: Between January 2025 and June 2025, a total of 152 individuals were included in this study, comprising 92 patients aged 18–45 who were diagnosed with PE and 60 healthy controls. The blood vitamin B12 levels of all participants were examined. Thirty-four patients with PE who presented with vitamin B12 deficiency were re-evaluated for ejaculation time after vitamin B12 replacement. RESULTS: The mean blood vitamin B12 level was 237.8 ± 91.4 ng/L in the PE group and 297 ± 141.7 ng/L in the control group (p = 0.002). Following vitamin B12 replacement in the PE group with vitamin B12 deficiency, there was a statistically significant decrease in Premature Ejaculation Diagnostic Tool (PEDT) scores, a significant increase in Premature Ejaculation Profile (PEP) scores, and an increase in intravaginal latency time (p < 0.001). Of the patients diagnosed with PE who received B12 replacement therapy, 25 (73.5%) were satisfied with the treatment, while 9 (26.5%) were dissatisfied. Treatment satisfaction rates were 87.5% in those with lifelong PE and 61.1% in those with acquired PE (p = 0.082). CONCLUSION: In PE patients with B12 deficiency, normalizing blood B12 levels may be a viable treatment option. This is the first study to assess the effect of B12 replacement in PE patients with vitamin B12 deficiency. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1186/s12894-026-02100-w.