Idiopathic OligoasthenoteratozoospermiaPhase 2/3NCT07669402
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 Phase 2/3 study testing Letrozole 2.5mg and L-carnitine in people with Idiopathic Oligoasthenoteratozoospermia and Male Infertility, run by Tehran University of Medical Sciences at 1 site in Iran.
Trial 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. Read more about this study
- Who is it for?
- Ages 20 to 45 years, men only
- Conditions the study is for
- Idiopathic Oligoasthenoteratozoospermia, Male Infertility
- What is being tested?
- Letrozole 2.5mg and L-carnitine
- Type of treatment
- Pill or oral medicine
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 90 participants
- Where
- 1 siteIran
- Study dates
- 1 Dec 2023to 31 Mar 2026
- Phase
- Phase 2/3
- Are there results?
- None posted in the registry
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 20 to 45 years
- Men only
- No healthy volunteers
- Adult
Who may be able to join
- 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
Who cannot join
- 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)
Trial locations and contacts
1 site in 1 country.
Iran1 site
Shariati Hospital, Tehran University of Medical Sciences
Tehran, 1417613151
About this study
Official 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.
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.
Read the detailed description
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.
- Being tested
- Letrozole 2.5mg, L-carnitine
- Keywords
- Oligoasthenoteratozoospermia, Male Infertility, Letrozole, L-Carnitine, Oxidative Stress, Sperm Quality, ART, ICSI
- Medical subject headings
- Infertility, Male, Oligospermia
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Letrozole 2.5mgDrug
Letrozole 2.5 mg tablet administered orally once daily for 3 months.
L-carnitineDrug
L-Carnitine 1000 mg capsule administered orally once daily for 3 months.
| Study group | Role | What they receive |
|---|---|---|
| Letrozole | Experimental | Letrozole 2.5 mg administered orally once daily for 3 months. Receives: Drug: Letrozole 2.5mg |
| L-Carnitine Monotherapy | Experimental | L-Carnitine 1000 mg administered orally once daily for 3 months. Receives: Drug: L-carnitine |
| Combination Therapy | Experimental | Letrozole 2.5 mg plus L-Carnitine 1000 mg administered orally once daily for 3 months. Receives: Drug: Letrozole 2.5mg; Drug: L-carnitine |
What is being measured
The primary outcome is the main question the study is designed to answer.
Sperm concentration (×10⁶/mL) after 3 months of treatment
Change in sperm concentration from baseline to 3 months post-treatment
Measured: 3 months
Progressive sperm motility (%) after 3 months of treatment
Change in progressive motility from baseline to 3 months post-treatment
Measured: 3 months
Normal sperm morphology (%) after 3 months of treatment
Change in normal morphology from baseline to 3 months post-treatment
Measured: 3 months
Secondary outcomes (5)
Serum testosterone and estradiol levels after 3 months of treatment
Change in hormonal profile from baseline to 3 months post-treatment
Measured: 3 months
Sperm DNA fragmentation index (DFI) after 3 months of treatment
Change in DFI from baseline to 3 months post-treatment
Measured: 3 months
Total antioxidant capacity (TAC) and reactive oxygen species (ROS) levels after 3 months of treatment
Total antioxidant capacity (TAC) and reactive oxygen species (ROS) levels after 3 months of treatment
Measured: 3 months
Mitochondrial membrane potential (MMP) after 3 months of treatment
Change in MMP from baseline to 3 months post-treatment
Measured: 3 months
Fertilization rate and embryo quality after ICSI
Assessment of fertilization rate and embryo quality following ICSI
Measured: 3 months
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted25 Jun 2026
- Study start1 Dec 2023
- Primary completion28 Feb 2026
- Study completion31 Mar 2026
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Idiopathic OligoasthenoteratozoospermiaStudies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase 2/3
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Model description
- Participants were randomly assigned to three parallel groups: Letrozole alone, L-Carnitine alone, or combination therapy.
- Masking
- Quadruple blind
- Who is masked
- Participant, Care provider, Investigator, Outcomes assessor
- Enrolment
- 90 participants (actual)
Sponsor and investigators
- Lead sponsor
- Tehran University of Medical Sciences
- Sponsor type
- University, hospital or other
- Responsible party
- Sponsor
- Investigators
- Azim Hedayatpour, Professor, PhD, Study chair, Tehran University of Medical Sciences
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07669402
- Sponsor's protocol ID
- IR.TUMS.MEDICINE.REC.1403.465
- Status last verified
- Jun 2026
- First submitted
- 20 Jun 2026
- Last updated
- 30 Jun 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No: Due to the specific nature of the data and restrictions from the ethics committee, individual participant data (IPD) will not be shared.
Study at a glance
From the registry record, last updated by the sponsor on 30 Jun 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official 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.
- ClinicalTrials.gov ID
- NCT07669402
- Acronym / sponsor ID
- IR.TUMS.MEDICINE.REC.1403.465
- Keywords
- Oligoasthenoteratozoospermia, Male Infertility, Letrozole, L-Carnitine, Oxidative Stress, Sperm Quality, ART, ICSI
- Phase
- Phase 2/3
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 90 participants (actual)
- Lead sponsor
- Tehran University of Medical SciencesUniversity, hospital or other
- Study start
- 1 Dec 2023 (actual)
- Primary completion
- 28 Feb 2026 (actual)
- Study completion
- 31 Mar 2026 (actual)
- First posted
- 25 Jun 2026 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
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.
Detailed description
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.
Study design
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Quadruple blind (participant, care provider, investigator, outcomes assessor)
- Number of arms
- 3
- Model description
- Participants were randomly assigned to three parallel groups: Letrozole alone, L-Carnitine alone, or combination therapy.
| Arm | Type | Receives |
|---|---|---|
| Letrozole | Experimental | Drug: Letrozole 2.5mgLetrozole 2.5 mg administered orally once daily for 3 months. |
| L-Carnitine Monotherapy | Experimental | Drug: L-carnitineL-Carnitine 1000 mg administered orally once daily for 3 months. |
| Combination Therapy | Experimental | Drug: Letrozole 2.5mg, Drug: L-carnitineLetrozole 2.5 mg plus L-Carnitine 1000 mg administered orally once daily for 3 months. |
Who may qualify
- Ages
- 20 to 45 years
- Sex
- Male only
- Healthy volunteers
- Not accepted
- Age groups
- Adult
Key inclusion criteria (4 listed)
- 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
Key exclusion criteria (5 listed)
- 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)
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| Letrozole 2.5mgLetrozole 2.5 mg tablet administered orally once daily for 3 months. | Drug | Combination Therapy, Letrozole |
| L-carnitineL-Carnitine 1000 mg capsule administered orally once daily for 3 months. | Drug | Combination Therapy, L-Carnitine Monotherapy |
Primary outcome
Sperm concentration (×10⁶/mL) after 3 months of treatment
Time frame: 3 months
Change in sperm concentration from baseline to 3 months post-treatment
Progressive sperm motility (%) after 3 months of treatment
Time frame: 3 months
Change in progressive motility from baseline to 3 months post-treatment
Normal sperm morphology (%) after 3 months of treatment
Time frame: 3 months
Change in normal morphology from baseline to 3 months post-treatment
5 secondary outcomes
Serum testosterone and estradiol levels after 3 months of treatment
Time frame: 3 months
Sperm DNA fragmentation index (DFI) after 3 months of treatment
Time frame: 3 months
Total antioxidant capacity (TAC) and reactive oxygen species (ROS) levels after 3 months of treatment
Time frame: 3 months
Mitochondrial membrane potential (MMP) after 3 months of treatment
Time frame: 3 months
Fertilization rate and embryo quality after ICSI
Time frame: 3 months
Results and safety
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 30 Jun 2026.
- Individual participant dataSharing planned: No. Due to the specific nature of the data and restrictions from the ethics committee, individual participant data (IPD) will not be shared.
Related trials for Idiopathic Oligoasthenoteratozoospermia
Not yet recruitingPhase 4
Comparative Efficacy of Antioxidants Alone Versus Combined Therapy With SERMs or FSH in Normogonadotropic Idiopathic OAT Patients: A Randomized Controlled Trial
Oligoasthenoteratozoospermia, Male Infertility
Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
Azim Hedayatpour, Professor, PhD study chair
Tehran University of Medical Sciences
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A Phase 2/3 study testing Letrozole 2.5mg and L-carnitine in people with Idiopathic Oligoasthenoteratozoospermia and Male Infertility, run by Tehran University of Medical Sciences at 1 site in Iran.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 4 inclusion and 5 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: finished, as of the sponsor's last update on 30 Jun 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in Iran. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
What does this combined phase mean?
Phase 2 studies give the treatment to a larger group to see whether it has the intended effect and to keep checking safety.
Phase 3 studies compare the treatment with the current standard treatment or a placebo in a large group, to confirm how well it works and watch for side effects.
Not every study follows the same path, and some studies (observational studies, device studies) have no phase.
Are results available for this study?
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Sperm concentration (×10⁶/mL) after 3 months of treatment (time frame: 3 months). The study lists 3 primary outcomes in all. It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 30 Jun 2026.