Introduction: Premature ejaculation (PE), one of the most common sexual dysfunctions in men, negatively affects sexual function and quality of life. Transcutaneous auricular vagal nerve stimulation (taVNS) provides autonomic regulation non-invasively by balancing the sympathetic and parasympathetic systems.

Objective: To investigate the effectiveness of taVNS on autonomic and sexual function in men with PE and to compare the effectiveness of different taVNS application methods.

Materials and Methods: This prospective, randomized, sham-controlled, single-blind (evaluator) study will be conducted on 102 men with PE. Physical, sociodemographic, and clinical characteristics will be evaluated. Heart rate variability will be assessed using the Polar H10 device, premature ejaculation status using the Premature Ejaculation Assessment Questionnaire, and sexual function using the International Index of Erectile Function. Participants will be randomized into two groups (intra-auricular taVNS and sham-taVNS). taVNS treatment will be administered to each group three days per week, with 20-minute sessions, for 12 weeks. For in-ear taVNS, bilateral ear sets with a 36-square-millimeter surface area will be used to stimulate the tragus and concha will be used to stimulate the tragus and concha for intra-auricular taVNS, while adhesive electrode pads with a similar surface area of 36 square millimeters (3 mm × 12 mm) will be used for retroauricular taVNS. The taVNS protocol includes bilateral auricular stimulation for 20 minutes, a stimulation frequency of 25 hertz (Hz), a pulse width of 250 μs, suprathreshold current (0.13-50 mA), and a biphasic mode. Sham group will also have the same specially designed electrodes placed inside the ear. The device will be turned on but set to 0 mA amplitude, so no electrical stimulation will be delivered.

Premature ejaculation (PE) is one of the most common sexual dysfunctions in men, profoundly affecting the quality of life of both the patient and their partner. Many of the proposed definitions for PE are not based on scientific data and lack diagnostic criteria. The International Society for Sexual Medicine (ISSM) defines PE (lifelong and acquired) as characterized by the following criteria: Ejaculation that occurs almost always or always before or within 1 minute of vaginal penetration (lifelong PE) or a clinically significant decrease in ejaculation latency time, typically to 3 minutes or less (acquired PE); Inability to delay ejaculation in almost all or all vaginal penetrations (lifelong and acquired PE); Negative personal consequences such as distress, anxiety, disappointment, and/or avoidance of sexual intimacy (lifelong and acquired PE). Epidemiological studies based on patient-reported outcome measures have found the prevalence of PE complaints in the male population to be as high as 20-30%. A review of the literature reveals that approaches such as behavioral therapy, exercise programs, neuromuscular electrical stimulation, and yoga are used in the treatment of premature ejaculation, in addition to pharmacological treatment. However, no study has been found that examines the effectiveness of transcutaneous auricular vagal nerve stimulation on autonomic function and PE in men with PE. Therefore, this study was designed to examine the effects of taVNS on autonomic function and PE in men with PE. Participants will be randomly assigned to two groups (intra-auricular taVNS and intra-auricular sham-taVNS). The taVNS will be administered to each group three days per week, with 20-minute session durations, for 12 weeks. The taVNS protocol includes bilateral auricular stimulation for 20 minutes, a stimulation frequency of 25 hertz (Hz), a pulse width of 250 μs, suprathreshold current (0.13-50 mA), and a biphasic mode. For intra-auricular taVNS, bilateral ear sets with a 36-square-millimeter surface area to stimulate the tragus and concha will be used for intra-auricular taVNS. Sham group will also have the same specially designed electrodes placed intra-auricularly. The device will be turned on but set to 0 mA amplitude, so no electrical stimulation will occur. Heart rate variability, Premature Ejaculation Assessment Questionnaire, International Index of Erectile Function will be assessed before and after treatment.

Inclusion Criteria:

• Having a diagnosis of premature ejaculation according to the International Society for Sexual Medicine (ISSM),
• Having the same, non-pregnant, sexually active partner for at least 6 months,
• Being in a stable, heterosexual relationship,
• Suffering from PE and seeking medical treatment.

Exclusion Criteria:

• Having acquired PE,
• History of vagotomy,
• Having diabetes, hypertension, cardiovascular disease,
• Abnormal neurological examination findings,
• Use of drugs that impair heart rate variability (agents, a-receptor agonists or antagonists, tricyclic or serotonergic antidepressants, antihypertensive drugs)
• History of pelvic surgery,
• Tobacco or alcohol use,
• Any organic cause of PE (as assessed by prostatic secretion analysis, thyroid-stimulating hormone);
• Having a psychiatric disorder,
• Having skin irritation/lesion at the application site,
• International Index of Erectile Function score below 26

Men who experience premature ejaculation will be included in the study.

A decision on this matter will be made later.

In this study, assessor blinding will be performed.