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.

NCT07669402 | Completed Phase 2

• 1 other identifier: IR.TUMS.MEDICINE.REC.1403.465
• Study Type: interventional
• Target: 90
• Locations: 1 country
• Sites: 1

Brief Summary

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.

Conditions

Idiopathic Oligoasthenoteratozoospermia; Male Infertility

Keywords

Oligoasthenoteratozoospermia; Male Infertility; Letrozole; L-Carnitine; Oxidative Stress; Sperm Quality; ART; ICSI

Outcome Measures

Primary Outcomes (3)

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

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

  3 months

• Progressive sperm motility (%) after 3 months of treatment

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

  3 months

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

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

  3 months

Secondary Outcomes (5)

• Serum testosterone and estradiol levels after 3 months of treatment

  3 months

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

  3 months

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

  3 months

• Mitochondrial membrane potential (MMP) after 3 months of treatment

  3 months

• Fertilization rate and embryo quality after ICSI

  3 months

Other Outcomes (3)

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

  3 months

• Incidence of treatment-related adverse events

  3 months

• Pregnancy outcomes (biochemical and clinical) following ICSI

  3 months

Study Arms (3)

Letrozole

EXPERIMENTAL

Letrozole 2.5 mg administered orally once daily for 3 months.

Drug: Letrozole 2.5mg

L-Carnitine Monotherapy

EXPERIMENTAL

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

Drug: L-carnitine

Combination Therapy

EXPERIMENTAL

Letrozole 2.5 mg plus L-Carnitine 1000 mg administered orally once daily for 3 months.

Drug: Letrozole 2.5mg; Drug: L-carnitine

Interventions

L-carnitine DRUG

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

Combination Therapy; L-Carnitine Monotherapy

Letrozole 2.5mg DRUG

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

Combination Therapy; Letrozole

Eligibility Criteria

• Age: 20 Years - 45 Years
• Sex: male
• Healthy Volunteers: No
• Age Groups: Adult (18-64)

You may qualify if:

• 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

You may not qualify if:

• 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)

Sponsors & Collaborators

• Tehran University of Medical Sciences: lead

Study Sites (1)

Shariati Hospital, Tehran University of Medical Sciences

Tehran, 1417613151, Iran

Location

MeSH Terms

Conditions

Infertility, Male; Oligospermia

Interventions

Letrozole; Carnitine

Condition Hierarchy (Ancestors)

Genital Diseases, Male; Genital Diseases; Urogenital Diseases; Infertility; Male Urogenital Diseases

Intervention Hierarchy (Ancestors)

Nitriles; Organic Chemicals; Triazoles; Azoles; Heterocyclic Compounds, 1-Ring; Heterocyclic Compounds; Trimethyl Ammonium Compounds; Quaternary Ammonium Compounds; Amines

Study Officials

• Azim Hedayatpour, Professor, PhD

  Tehran University of Medical Sciences

  STUDY CHAIR

Study Design

• Study Type: interventional
• Phase: phase 2
• Allocation: RANDOMIZED
• Masking: QUADRUPLE
• Who Masked: PARTICIPANT, CARE PROVIDER, INVESTIGATOR, OUTCOMES ASSESSOR
• Masking Details: All participants, care providers, investigators, and outcome assessors were blinded to group allocation.
• Purpose: TREATMENT
• Intervention Model: PARALLEL
• Sponsor Type: OTHER
• Responsible Party: SPONSOR

Model Details: Participants were randomly assigned to three parallel groups: Letrozole alone, L-Carnitine alone, or combination therapy.

Study Record Dates

• First Submitted: June 20, 2026
• First Posted: June 25, 2026
• Study Start: December 1, 2023
• Primary Completion: February 28, 2026
• Study Completion: March 31, 2026
• Last Updated: June 30, 2026

Record last verified: 2026-06

Data Sharing

• IPD Sharing: Will not share

Locations

IR (1)