ClinicalTrials.gg
Enrolling by invitationNCT07481370Updated Apr 20, 2026

Isotretinoin vs hCG for Male Infertility Due to Low or Absent Sperm

A Phase 2 interventional study of isotretinoin and Human chorionic gonadotrophin (hCG) in Oligospermia, Azoospermia, Nonobstructive and Infertility, sponsored by University of Nebraska. Enrolling by invitation at 1 site in United States. Open to male participants aged 19 Years to 50 Years. Per ClinicalTrials.gov, last updated 2026-04-20.

Sponsored by University of Nebraska · Phase 2, Interventional, and Treatment

Phase
Phase 2
Study type
Interventional
Enrollment
100
Allocation
Randomized
Ages
19 Years to 50 Years
Sex
Male
01

Study summary

This study compares two medical treatments to see how well they improve sperm production in men with infertility due to low sperm counts (oligospermia) or no sperm in the semen due to non-obstructive causes (nonobstructive azoospermia). Some men with these conditions have limited nonsurgical treatment options, and current therapies do not work for everyone.

Participants in this study will be adult men ages 19 to 50 who have been diagnosed with oligospermia or nonobstructive azoospermia and do not have a correctable cause for infertility. Eligible participants will be randomly assigned to receive one of two treatments for three months: oral isotretinoin taken twice daily, or human chorionic gonadotropin (hCG) injections given three times per week. hCG is a standard hormonal therapy used in certain types of male infertility, while isotretinoin is being studied for its potential role in stimulating sperm production.

At the start of the study, participants will have blood tests to measure reproductive hormone levels and a semen analysis. Blood tests will be repeated at one month and three months, and a repeat semen analysis will be performed at three months, which corresponds to a full cycle of sperm development. The main goal of the study is to determine whether motile (moving) sperm appear in the semen after treatment. Additional goals include measuring changes in sperm count and hormone levels, as well as monitoring medication side effects.

Both study medications are FDA-approved and have known side effect profiles. Participants may or may not experience improvement in sperm production. The results of this study may help guide future treatment options for men with infertility due to low or absent sperm production.

02

Conditions studied

  • Oligospermia
  • Azoospermia, Nonobstructive
  • Infertility
03

In context

Oligospermia

64 studies on the registry are indexed under Oligospermia; 17 are open to participants now.

This study's planned enrollment of 100 is above the median of 65 across 46 interventional studies indexed under Oligospermia.

Browse Oligospermia studies →

Lead sponsor

University of Nebraska is the lead sponsor of 496 studies on the registry; 67 are open to participants now.

Of its 83 completed or terminated interventional studies of FDA-regulated products, 53 (64%) have results posted.

Counted across the registry records on this site, refreshed daily.

04

Who can participate

Ages eligible
19 Years to 50 Years
Sexes eligible
Male
Accepts healthy volunteers
No

Go through the criteria one by one — yes, no or not sure — and take the list to your doctor or the study team. Kept in this browser only.

Inclusion criteria

  • Male participants aged 19 to 50 years
  • Confirmed diagnosis of oligospermia (sperm concentration \<15 million/mL), nonobstructive azoospermia, or hypogonadotropic hypogonadism (defined by low or normal FSH with low testosterone)
  • Normal genetic evaluation if diagnosed with azoospermia
  • No other identified and correctable cause of infertility
  • Considered appropriate candidates for medical therapy for infertility in the clinical judgment of the investigators
  • Willing and able to comply with study procedures, including laboratory testing, semen analyses, and follow-up visits
  • Able to provide

Exclusion criteria

Exclusion Criteria:

  • Obstructive azoospermia (including vasal obstruction, ejaculatory duct obstruction, or prior vasectomy)
  • Prior successful medical therapy for infertility
  • Current or recent use of medications known to impair spermatogenesis, including exogenous testosterone or anabolic steroids, unless discontinued with adequate
  • Current use of isotretinoin for any indication
  • to isotretinoin (including significant liver disease or uncontrolled hyperlipidemia)
  • Contraindications to human chorionic gonadotropin (including hormone-sensitive )
  • Significant medical or psychiatric conditions that, in the opinion of the investigators, would interfere with safe participation
  • Inability to provide semen samples
  • Inability to provide
Terms in these criteria, in plain language(4)

Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.

Informed consent

Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.

You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.

Washout period

A planned gap after a treatment, so that its effects can lessen before the study treatment or a study assessment. Ask the study team and the doctor who prescribed it before changing any medicine.

Contraindication

A reason a treatment, test or procedure should not be given to a particular person, such as an allergy, another illness or a medicine they take.

Cancer (malignancy)

Malignancy means cancer. Criteria about another or earlier malignancy ask whether you have had a different cancer, usually within a set number of years.

Some are commonly allowed, such as treated skin cancers other than melanoma and early cancers removed completely — check the exceptions this study lists.

05

Study design

Phase
Phase 2
Primary purpose
Treatment
Allocation
Randomized
Intervention model
Parallel assignment
Masking
None (open label)
Enrollment
100 participants (estimated)

Study arms

  • Experimental
    Isotretinoin Treatment Arm

    Participants in this arm will receive oral isotretinoin 20 mg twice daily for 3 months. Reproductive hormone testing will be performed at baseline, 1 month, and 3 months, and a semen analysis will be repeated at 3 months to assess treatment response.

    Drug: isotretinoin

  • Active comparator
    hCG Treatment Arm

    Participants in this arm will receive human chorionic gonadotropin (hCG) injections at a dose of 2,000 units three times weekly for 3 months. Reproductive hormone testing will be performed at baseline, 1 month, and 3 months, and a semen analysis will be repeated at 3 months to assess treatment response

    Drug: Human chorionic gonadotrophin (hCG)

Interventions

  • Oral isotretinoin administered at a dose of 20 mg twice daily for 3 months as part of a randomized treatment arm evaluating effects on sperm production and reproductive hormone levels.

  • Human chorionic gonadotropin (hCG) administered by subcutaneous injection at a dose of 2,000 units three times weekly for 3 months as part of a randomized treatment arm evaluating effects on sperm production and reproductive hormone levels.

06

What researchers measure

Primary outcomes

  1. Presence of Motile Sperm in the Ejaculate

    Assessment of whether motile (moving) sperm are present in the ejaculate following treatment with isotretinoin or human chorionic gonadotropin (hCG), as determined by standard semen analysis

    Time frame: 3 months

07

Study locations

1 site
08

References and documents

Individual participant data

Plan to share: No

No publications or documents are linked to this record.

09

Timeline

Tracking since Sep 25, 2026
ElapsedEstimatedEstimated, not yet reached

Started Apr 2026 (actual). Primary completion is estimated for Jun 2027, 14 months after the start.

How these figures are worked out, and which studies are left out of them.

Registered
Mar 13, 2026
First posted
Mar 18, 2026
StartActual
Apr 13, 2026
Primary completionEst.
Jun 30, 2027
CompletionEst.
Dec 31, 2027
Last update
Apr 20, 2026
What these dates mean
Start.
When the first participant enrolled; while estimated, when the study expects to open to recruitment.
Primary completion.
When the last participant was examined or treated to collect data for the study's main question, its primary outcome. A study that stopped early gives the date its data collection stopped.
Completion.
When the last participant's last visit took place, for every outcome, secondary ones and side effects included: the end of the study. Often later than primary completion, sometimes the same day.
Actual and Est.
Actual means the registry says the date has happened. Est. (estimated) is a date the sponsor plans or expects. It can still move, and the sponsor is expected to change it to actual once it has passed.
No changes since tracking began. The registry record was last updated on Apr 20, 2026, before this site started recording changes on Sep 25, 2026. Its history is on ClinicalTrials.gov ↗
10

Registry details

Key details

Study ID
NCT07481370
Responsible party
Christopher Deibert (Chris Deibert MD, MPH Program Director & Associate Professor, Urologic Surgery, Nebraska Medicine-UNMC, University of Nebraska) — Principal investigator
First posted
Mar 18, 2026
Start date
Apr 13, 2026
Primary completion
Jun 30, 2027 (estimated)
Completion
Dec 31, 2027 (estimated)
Last update
Apr 20, 2026

Study contacts

Chris Deibert, MD, MPH
principal investigator · University of Nebraska

Oversight

Data monitoring committee
No
FDA-regulated drug
Yes
FDA-regulated device
No
View the source record on ClinicalTrials.gov ↗

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No contact was published for this record. The registry link below has the sponsor’s details.

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Studies of the drug tested here: Isotretinoin

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