ClinicalTrials.gg
CompletedNCT05381831Updated Jun 13, 2025

Natesto Spermatogenesis Reboot

A Phase 4 interventional study of NatestoTM in Hypogonadism, Male, sponsored by University of Florida. Completed at 1 site in United States. Open to male participants aged 18 Years to 64 Years. Per ClinicalTrials.gov, last updated 2025-06-13.

Sponsored by University of Florida · Phase 4, Interventional, and Treatment

From the registry’s dates

  • Primary completion was Apr 2025, 1 year 6 months ago, and no results have been posted to the registry.
Phase
Phase 4
Study type
Interventional
Enrollment
13
Allocation
Not applicable
Ages
18 Years to 64 Years
Sex
Male
01

Study summary

This is a prospective, non-blinded study of hypogonadal men with a history of testosterone therapy who became azoospermic or severely oligospermic and wish to avoid symptoms of hypogonadism during their recovery of spermatogenesis in an effort to establish paternity. The study will determine if Natesto can alleviate hypogonadal symptoms while preserving the recovery of spermatogenesis

02

Conditions studied

  • Hypogonadism, Male

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03

In context

Eunuchism

75 studies on the registry are indexed under Eunuchism; 21 are open to participants now.

This study's enrollment of 13 is below the median of 60 across 55 interventional studies indexed under Eunuchism.

Browse Eunuchism studies →

Lead sponsor

University of Florida is the lead sponsor of 1,287 studies on the registry; 199 are open to participants now.

Of its 180 completed or terminated interventional studies of FDA-regulated products, 143 (79%) have results posted.

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

04

Who can participate

Ages eligible
18 Years to 64 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 between 18 and 64 years of age, with documented onset of testosterone induced hypogonadism with impaired semen parameters who are attempting to achieve a successful pregnancy.
  • Documented diagnosis of primary hypogonadism (congenital or acquired) or hypogonadotropic hypogonadism (congenital or acquired).
  • Serum total testosterone \< 350 ng/dL based on 2 consecutive blood samples obtained 1-4 weeks apart between 6 and 10 AM following an appropriate of current androgen replacement therapy; with clinical symptoms of hypogonadism such as diminished energy and sexual function; and/or a decreased sperm count (\<20 million sperm/mL semen).
  • Discontinued current testosterone replacement treatment and completed a washout of 4 weeks following androgen treatment (excluding Testopel TM). Washout must be completed prior to collection of baseline serum testosterone samples to determine study eligibility.
  • Judged to be in good general health as determined by the principal investigator based upon the results of a medical history, physical examination, vital signs, and laboratory profile.

Exclusion criteria

Exclusion Criteria:

  • History of significant sensitivity or allergy to androgens, castor oil or product .
  • findings in the pre-study examinations including abnormal breast examination requiring follow-up.
  • Abnormal prostate digital rectal examination (DRE) with palpable nodule(s) or I-PSS score greater than 19 points.
  • (BMI) equal to or greater than or equal to 40 kg/m2.
  • History of vasectomy.
  • Clinically significant abnormal laboratory value, in the opinion of the investigator, in serum chemistry, hematology, or urinalysis including but not limited to:

    1. Baseline greater than 16 g/dL
    2. Hematocrit less than 35% or greater than 50%
    3. PSA greater than 4 ng/mL and age greater than 40
  • History of seizures or convulsions, including febrile, alcohol or drug withdrawal seizures.
  • History of any clinically significant illness, infection, or surgical procedure within 4 weeks prior to study drug administration.
  • History of stroke or myocardial infarction within the past 5 years.
  • History of, or current or suspected, prostate or breast cancer.
  • History of diagnosed, severe, untreated, obstructive sleep apnea.
  • History of abuse of alcohol or any drug substance in the opinion of the investigator within the previous 2 years.
  • History of nasal disorders such as nasal polyps; nasal septal perforation; nasal surgery; nasal trauma resulting in nasal fracture within the previous 6 months or nasal fracture that caused a deviated anterior nasal septum; sinus surgery or sinus disease
  • Donation or loss of 550 mL or more blood volume (including plasmapheresis) or receipt of a transfusion of any blood product within 12 weeks prior to the start of treatment.
  • Inadequate venous access for collection of serial blood samples required for pharmacokinetic profiles.
  • Receipt of any product within 4 weeks or within 5 half-lives prior to the start of treatment.
  • Inability to understand and provide written for the study.
  • Considered by the investigator or the sponsor-designated physician, for any reason, that the subject is an unsuitable candidate to receive Natesto.
Terms in these criteria, in plain language(7)

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.

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.

Excipients

The other ingredients in a medicine besides the active drug, such as fillers, colours or preservatives.

Clinically significant

Judged by the study doctor to matter for your health or for the study. It is a doctor’s decision, so ask the study team if you are unsure whether something counts.

BMI (body mass index)

Weight in kilograms divided by height in metres squared. Example: 70 kg and 1.75 m gives 70 ÷ (1.75 × 1.75) ≈ 22.9.

What counts as overweight or obesity differs between countries (some use lower cut-offs), so go by the range the study states.

Hemoglobin (Hb)

The protein in red blood cells that carries oxygen. A low level is anaemia, which can cause tiredness and breathlessness. Measured in g/dL or g/L (9 g/dL is 90 g/L).

Investigational drug or device

A drug or device being studied in a clinical trial.

It may be new, or already approved and being studied for another use, dose or form. Criteria often leave out people who took part in another study of one within a recent period, commonly 30 days or five half-lives.

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.

05

Study design

Phase
Phase 4
Primary purpose
Treatment
Allocation
Not applicable
Intervention model
Single group
Masking
None (open label)
Enrollment
13 participants (actual)

Study arms

  • Experimental
    NatestoTM

    Participants in this group will receive Natesto for a 26 consecutive weeks treatment course

    Drug: NatestoTM

Interventions

  • DrugNatestoTM

    Administering daily intranasal testosterone, Natesto nasal gel is available as a metered-dose pump. One pump actuation delivers 5.5 mg of testosterone

06

What researchers measure

Primary outcomes

  1. Changes in total motile sperm count

    Change in sperm count will be analyzed using the ANOVA. A change in \< ± 10% will be reject the null hypothesis.

    Time frame: Baseline up to 26 weeks

07

Study locations

1 site
  • University of Florida
    Gainesville, Florida 32610, United States
08

References and documents

Study documents

PDFs hosted by the registry, ClinicalTrials.gov.

Individual participant data

Plan to share: No

09

Updates

Tracking since Sep 25, 2026
No changes since tracking began. The registry record was last updated on Jun 13, 2025, before this site started recording changes on Sep 25, 2026. Its history is on ClinicalTrials.gov ↗
10

Registry details

Key details

Study ID
NCT05381831
Responsible party
Sponsor
First posted
May 19, 2022
Start date
Jun 1, 2022
Primary completion
Apr 21, 2025
Completion
Apr 21, 2025
Last update
Jun 13, 2025

Study contacts

Kevin Campbell, MD
principal investigator · University of Florida

Oversight

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

Not currently enrolling

This study is completed, as verified in Jun 2025. You cannot join it, but the record below documents what was studied.

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