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NCT Number: NCT07669402

Comparative Evaluation of the Efficacy of Letrozole, L-Carnitine, and Their Combination on Sperm Quality, Oxidative Stress, and ART Outcomes in Men With Idiopathic Oligoasthenoteratozoospermia.

This is a randomized clinical trial evaluating the efficacy of Letrozole, L-Carnitine, and their combination on sperm quality, oxidative stress, and ART outcomes in men with idiopathic oligoasthenoteratozoospermia.

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Key information

Conditions

Idiopathic Oligoasthenoteratozoospermia Genital Diseases Genital Diseases, Male Infertility Infertility, Male Male Infertility Male Urogenital Diseases Oligospermia Urogenital Diseases

Age range

20 year–45 year

Sex eligibility

Male

Study type

Interventional

Phase

Phase 2 / Phase 3

Primary location

Shariati Hospital, Tehran University of Medical Sciences

Tehran, 1417613151, Iran

About this study

This three-arm randomized controlled trial included 90 men with idiopathic oligoasthenoteratozoospermia (iOAT) who were assigned to receive Letrozole (2.5 mg/day), L-Carnitine (1000 mg/day), or combination therapy for 3 months. Sperm parameters, hormonal profiles, oxidative stress biomarkers, mitochondrial function, and ICSI outcomes were assessed before and after treatment.

Who can participate

Healthy volunteers accepted: No

Only the study team can determine whether someone qualifies for participation.

Inclusion criteria

Diagnosis of idiopathic oligoasthenoteratozoospermia (iOAT) per WHO 2021 criteria

Age 20 to 45 years

BMI between 18 and 30 kg/m²

No prior hormonal therapy or antioxidant supplements within the last 3 months

Exclusion criteria

Varicocele, cryptorchidism, or genital tract infection

Hormonal disorders (hypogonadism, hyperprolactinemia, thyroid dysfunction)

Smoking, alcohol use, or drug abuse

Use of testosterone or anabolic steroids within the last 6 months

Female partner with severe infertility factors (age ≥40, tubal blockage, severe endometriosis)

Treatment and study plan

Letrozole 2.5mg

Drug

Letrozole 2.5 mg tablet administered orally once daily for 3 months.

L-carnitine

Drug

L-Carnitine 1000 mg capsule administered orally once daily for 3 months.

Primary outcomes

  1. Sperm concentration (×10⁶/mL) after 3 months of treatment

    Time frame: 3 months

    Change in sperm concentration from baseline to 3 months post-treatment

  2. Progressive sperm motility (%) after 3 months of treatment

    Time frame: 3 months

    Change in progressive motility from baseline to 3 months post-treatment

  3. Normal sperm morphology (%) after 3 months of treatment

    Time frame: 3 months

    Change in normal morphology from baseline to 3 months post-treatment

Secondary outcomes

  1. Serum testosterone and estradiol levels after 3 months of treatment

    Time frame: 3 months

    Change in hormonal profile from baseline to 3 months post-treatment

  2. Sperm DNA fragmentation index (DFI) after 3 months of treatment

    Time frame: 3 months

    Change in DFI from baseline to 3 months post-treatment

  3. Total antioxidant capacity (TAC) and reactive oxygen species (ROS) levels after 3 months of treatment

    Time frame: 3 months

    Total antioxidant capacity (TAC) and reactive oxygen species (ROS) levels after 3 months of treatment

  4. Mitochondrial membrane potential (MMP) after 3 months of treatment

    Time frame: 3 months

    Change in MMP from baseline to 3 months post-treatment

  5. Fertilization rate and embryo quality after ICSI

    Time frame: 3 months

    Assessment of fertilization rate and embryo quality following ICSI

Other outcomes

  1. Percentage of patients with improved sperm parameters (concentration, motility, morphology) after treatment

    Time frame: 3 months

    Proportion of patients showing clinical improvement in at least one sperm parameter

  2. Incidence of treatment-related adverse events

    Time frame: 3 months

    Monitoring and recording of any adverse events related to the study interventions

  3. Pregnancy outcomes (biochemical and clinical) following ICSI

    Time frame: 3 months

    Assessment of biochemical and clinical pregnancy rates after embryo transfer

Sponsors and collaborators

Lead sponsor

Tehran University of Medical Sciences

Other

Registry information

Official study title

Comparative Evaluation of the Efficacy of Letrozole, L-Carnitine, and Their Combination on Sperm Quality, Oxidative Stress, and ART Outcomes in Men With Idiopathic Oligoasthenoteratozoospermia: A Three-Arm Randomized Clinical Trial.

Important dates

Study start
2023
Primary completion
2026
Study completion
2026
First posted
Jun 25, 2026
Registry last updated
Jun 30, 2026

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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