A Phase 3 interventional study of Testosterone Cypionate 75 mg and Testosterone cypionate 50 mg in Male Hypogonadism, sponsored by Amneal Pharmaceuticals, LLC. Recruiting at 10 sites in United States. Open to male participants aged 18 Years to 75 Years. Per ClinicalTrials.gov, last updated 2026-10-27.
Sponsored by Amneal Pharmaceuticals, LLC · Phase 3, Interventional, and Treatment
The goal of this Phase 3 clinical trial is to evaluate the safety, efficacy, and usability of a weekly subcutaneous testosterone cypionate auto-injector in adult males with hypogonadism. The main questions it aims to answer are:
All participants will receive testosterone cypionate administered subcutaneously once weekly through an auto-injector. Treatment will begin at a 75 mg weekly dose, with dose adjustments to 50 mg or 100 mg based on testosterone levels measured during the study.
Participants will:
This study will enroll adult males aged 18 to 75 years with hypogonadism and low testosterone concentrations to evaluate treatment through Week 24, with continued safety follow-up through Week 52.
Hypogonadism in adult males is characterized by inadequate testosterone production and may be associated with reduced energy, decreased libido, diminished muscle mass and strength, impaired physical function, and other clinical symptoms. Testosterone replacement therapy is commonly used to restore serum testosterone concentrations to the normal physiological range and improve symptoms associated with testosterone deficiency.
This Phase 3, multicenter, single-arm, multiple-dose study is designed to evaluate the long-term efficacy, safety, pharmacokinetic profile, and usability of testosterone cypionate administered subcutaneously via a prefilled weekly auto-injector in adult males with hypogonadism. The study seeks to characterize the ability of the investigational product to achieve and maintain serum testosterone concentrations within the target eugonadal range during chronic administration.
Participants will initiate treatment with a weekly subcutaneous dose of testosterone cypionate administered using the auto-injector. Dose adjustments may be implemented during the study based on serum testosterone concentrations to optimize therapeutic exposure. Pharmacokinetic assessments will be performed to characterize testosterone exposure following repeated dosing and to evaluate maintenance of testosterone concentrations over time.
In addition to evaluating testosterone concentrations, the study will assess the long-term safety and tolerability of weekly subcutaneous testosterone cypionate. Safety evaluations will include monitoring of adverse events, clinical laboratory parameters, vital signs, physical examinations, and other assessments routinely used to evaluate testosterone replacement therapy.
The study will also evaluate participant experience with the auto-injector, including ease of use and successful self-administration. Information obtained from this study is intended to support the clinical evaluation of a convenient, once-weekly subcutaneous testosterone replacement option for adult males with hypogonadism.
This study includes a treatment period and an extension phase to provide additional long-term safety and efficacy data following repeated administration of testosterone cypionate using the auto-injector device.
75 studies on the registry are indexed under Eunuchism; 21 are open to participants now.
This study's planned enrollment of 190 is above the median of 60 across 55 interventional studies indexed under Eunuchism.
Browse Eunuchism studies →Amneal Pharmaceuticals, LLC is the lead sponsor of 13 studies on the registry; 3 are open to participants now.
Counted across the registry records on this site, refreshed daily.
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.
Exclusion Criteria:
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.
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.
Ways of preventing pregnancy. “Highly effective” methods fail less than 1% of the time a year when used correctly — for example an IUD or an implant.
Criteria usually say which methods count and how long to keep using them after the last dose, sometimes for male participants too. Some studies accept a partner’s vasectomy if it was confirmed successful and that person is the participant’s only sexual partner.
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).
A blood test of average blood sugar over the past two to three months, given as a percentage or in mmol/mol. 6.5% (48 mmol/mol) or more is the usual threshold for diabetes, normally confirmed by a second test.
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.
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.
An allergy, or another reaction of the immune system, to a substance. “Hypersensitivity to the study drug” means a known allergic reaction to it — not every side effect a medicine can have.
The New York Heart Association’s four classes of how much heart failure limits physical activity.
Studies set their own limit — many outside heart failure leave out class III–IV, while heart failure studies may ask for a particular class. Check the class this study names.
A “mini-stroke”: temporary stroke-like symptoms caused by reduced blood flow to part of the brain, spinal cord or eye, without signs of a new stroke on a scan.
Stroke symptoms need emergency care at once, even if they go away.
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.
A recording of the heart’s electrical activity, taken with stickers on the chest, arms and legs. It takes a few minutes and does not hurt.
On an ECG, the QT interval is the time the heart’s lower chambers take to activate electrically and recover in each beat. QTc is that time adjusted for heart rate (QTcF by Fridericia’s formula, QTcB by Bazett’s). Some medicines lengthen it, and a long QTc can raise the risk of a dangerous heart rhythm.
The study may name a correction formula and a limit in milliseconds, often around 450–480.
GFR (glomerular filtration rate) is how much blood the kidneys filter each minute. It is usually estimated from a blood test — eGFR, by formulas such as CKD-EPI or MDRD — and some studies ask for it to be measured directly instead. Usually given in mL/min/1.73 m².
Check the method, the units and the minimum the study states. A value of 90 or above is in the normal-or-high range, but kidney damage can show in other tests too.
Two enzymes measured in a routine blood test of the liver. Higher levels can mean the liver is under strain or damaged. SGPT and SGOT are older names for ALT and AST.
Criteria usually give a limit as a multiple of the upper limit of normal (ULN), often higher when cancer has spread to the liver.
The top of the normal range for a blood test, as set by the laboratory that runs it. Each lab prints its own range next to your result.
“≤ 2.5 × ULN” means the result can be up to two and a half times that top value.
The human immunodeficiency virus, which weakens the immune system.
Many studies now accept people whose HIV is controlled on treatment, judged by the viral load and the CD4 count. Check the limits this study sets.
Hepatitis B is a virus that infects the liver. These are separate tests: HBsAg positive usually means a current infection (a recent vaccination can briefly cause it too); total anti-HBc (HBcAb) positive means an infection now or in the past; HBV DNA measures how much virus is in the blood.
Some studies accept a past infection if HBV DNA is undetectable, sometimes with antiviral medicine during the study. Check what this study allows.
Hepatitis C is a virus that infects the liver. An HCV antibody test can stay positive after an infection has cleared (and is occasionally positive without one); an HCV RNA test shows whether the virus is there now.
After treatment, hepatitis C counts as cured when HCV RNA is still undetectable 12 weeks or more after the treatment ended. Studies often accept people cured this way.
Anti-inflammatory medicines such as prednisone, prednisolone and dexamethasone — not the anabolic steroids used for muscle.
Studies differ in what they allow: check which steroid medicines, routes (tablets, injections, creams, inhalers, eye drops) and doses this study accepts.
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.
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.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Contraception
Ways of preventing pregnancy. “Highly effective” methods fail less than 1% of the time a year when used correctly — for example an IUD or an implant.
Criteria usually say which methods count and how long to keep using them after the last dose, sometimes for male participants too. Some studies accept a partner’s vasectomy if it was confirmed successful and that person is the participant’s only sexual partner.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
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).
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
HbA1c
A blood test of average blood sugar over the past two to three months, given as a percentage or in mmol/mol. 6.5% (48 mmol/mol) or more is the usual threshold for diabetes, normally confirmed by a second test.
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.
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.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Hypersensitivity
An allergy, or another reaction of the immune system, to a substance. “Hypersensitivity to the study drug” means a known allergic reaction to it — not every side effect a medicine can have.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
NYHA class (heart failure)
The New York Heart Association’s four classes of how much heart failure limits physical activity.
Studies set their own limit — many outside heart failure leave out class III–IV, while heart failure studies may ask for a particular class. Check the class this study names.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
TIA (transient ischaemic attack)
A “mini-stroke”: temporary stroke-like symptoms caused by reduced blood flow to part of the brain, spinal cord or eye, without signs of a new stroke on a scan.
Stroke symptoms need emergency care at once, even if they go away.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
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.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
ECG (electrocardiogram)
A recording of the heart’s electrical activity, taken with stickers on the chest, arms and legs. It takes a few minutes and does not hurt.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
QT and QTc
On an ECG, the QT interval is the time the heart’s lower chambers take to activate electrically and recover in each beat. QTc is that time adjusted for heart rate (QTcF by Fridericia’s formula, QTcB by Bazett’s). Some medicines lengthen it, and a long QTc can raise the risk of a dangerous heart rhythm.
The study may name a correction formula and a limit in milliseconds, often around 450–480.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
GFR and eGFR (kidney filtering)
GFR (glomerular filtration rate) is how much blood the kidneys filter each minute. It is usually estimated from a blood test — eGFR, by formulas such as CKD-EPI or MDRD — and some studies ask for it to be measured directly instead. Usually given in mL/min/1.73 m².
Check the method, the units and the minimum the study states. A value of 90 or above is in the normal-or-high range, but kidney damage can show in other tests too.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
ALT and AST (liver enzymes)
Two enzymes measured in a routine blood test of the liver. Higher levels can mean the liver is under strain or damaged. SGPT and SGOT are older names for ALT and AST.
Criteria usually give a limit as a multiple of the upper limit of normal (ULN), often higher when cancer has spread to the liver.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
ULN (upper limit of normal)
The top of the normal range for a blood test, as set by the laboratory that runs it. Each lab prints its own range next to your result.
“≤ 2.5 × ULN” means the result can be up to two and a half times that top value.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
HIV
The human immunodeficiency virus, which weakens the immune system.
Many studies now accept people whose HIV is controlled on treatment, judged by the viral load and the CD4 count. Check the limits this study sets.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Hepatitis B tests
Hepatitis B is a virus that infects the liver. These are separate tests: HBsAg positive usually means a current infection (a recent vaccination can briefly cause it too); total anti-HBc (HBcAb) positive means an infection now or in the past; HBV DNA measures how much virus is in the blood.
Some studies accept a past infection if HBV DNA is undetectable, sometimes with antiviral medicine during the study. Check what this study allows.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Hepatitis C tests
Hepatitis C is a virus that infects the liver. An HCV antibody test can stay positive after an infection has cleared (and is occasionally positive without one); an HCV RNA test shows whether the virus is there now.
After treatment, hepatitis C counts as cured when HCV RNA is still undetectable 12 weeks or more after the treatment ended. Studies often accept people cured this way.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Corticosteroids (steroids)
Anti-inflammatory medicines such as prednisone, prednisolone and dexamethasone — not the anabolic steroids used for muscle.
Studies differ in what they allow: check which steroid medicines, routes (tablets, injections, creams, inhalers, eye drops) and doses this study accepts.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
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.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Participants with hypogonadism will receive testosterone cypionate injection administered subcutaneously into the abdomen once weekly using an auto-injector. All participants will initiate treatment at 75 mg once weekly.
Drug: Testosterone Cypionate 75 mg
Participants with hypogonadism will receive testosterone cypionate injection administered subcutaneously into the abdomen once weekly using an auto-injector. All participants will initiate treatment at 75 mg once weekly. The dose may be adjusted to 50 mg based on serum total testosterone trough concentrations and protocol-defined dose titration criteria.
Drug: Testosterone cypionate 50 mg
Participants with hypogonadism will receive testosterone cypionate injection administered subcutaneously into the abdomen once weekly using an auto-injector. All participants will initiate treatment at 75 mg once weekly. The dose may be adjusted to100 mg based on serum total testosterone trough concentrations and protocol-defined dose titration criteria. Treatment will continue through the 24-week primary evaluation period. Participants completing Week 24 may continue once-weekly treatment with ongoing safety assessments through Week 52. The first dose will be administered by designated study personnel, followed by participant self-administration as specified in the protocol.
Drug: Testosterone cypionate 100 mg
Testosterone cypionate injectable solution formulated in cottonseed oil, supplied in a single-use auto-injector containing 75 mg/0.5 mL. The study drug will be administered subcutaneously into the abdomen once weekly. All participants will initiate treatment at 75 mg once weekly, with dose adjustments in 25 mg increments to 50 mg or 100 mg based on serum total testosterone trough concentrations according to protocol-defined criteria. Treatment will continue through the 24-week primary evaluation period, with eligible participants permitted to continue once-weekly treatment through Week 52 for extended safety assessment.
Testosterone cypionate injectable solution formulated in cottonseed oil, supplied in a single-use auto-injector containing 50 mg/0.5 mL. The study drug will be administered subcutaneously into the abdomen once weekly. All participants will initiate treatment at 75 mg once weekly, with dose adjustments in 25 mg increments to 50 mg or 100 mg based on serum total testosterone trough concentrations according to protocol-defined criteria. Treatment will continue through the 24-week primary evaluation period, with eligible participants permitted to continue once-weekly treatment through Week 52 for extended safety assessment.
Testosterone cypionate injectable solution formulated in cottonseed oil, supplied in a single-use auto-injector containing 100 mg/0.5 mL. The study drug will be administered subcutaneously into the abdomen once weekly. All participants will initiate treatment at 75 mg once weekly, with dose adjustments in 25 mg increments to 50 mg or 100 mg based on serum total testosterone trough concentrations according to protocol-defined criteria. Treatment will continue through the 24-week primary evaluation period, with eligible participants permitted to continue once-weekly treatment through Week 52 for extended safety assessment.
Percentage of Participants With Average Serum Total Testosterone Concentration Within 300-1100 ng/dL at Week 12
The percentage of participants whose average serum total testosterone concentration (Cavg) over the 168-hour (7-day) dosing interval at Week 12 is within the predefined range of 300-1100 ng/dL. Serum total testosterone concentrations will be measured using blood samples collected before and at specified time points after dosing through 168 hours. Cavg will be calculated by dividing the area under the serum concentration-time curve from 0 to 168 hours (AUC0-168h) by 168 hours. The primary efficacy criterion is met if at least 75% of participants achieve the specified range, with the lower bound of the two-sided 95% confidence interval at least 65%. The assessment will be based on the protocol-defined full pharmacokinetic population.
Time frame: Week 12 (over the 168-hour dosing interval following the Week 12 dose)
Percentage of Participants With Maximum Serum Total Testosterone Concentration (Cmax) Below 1500 ng/dL at Week 12
The percentage of participants whose maximum serum total testosterone concentration (Cmax) is below 1500 ng/dL during the 168-hour dosing interval at Week 12. Cmax will be determined from serial blood samples collected following the weekly subcutaneous dose. The protocol-defined safety criterion is met if at least 85% of participants have Cmax below 1500 ng/dL.
Time frame: Week 12 (0-168 hours after dosing)
Percentage of Participants With Maximum Serum Total Testosterone Concentration (Cmax) Between 1800 and 2500 ng/dL at Week 12
The percentage of participants whose maximum serum total testosterone concentration (Cmax) is between 1800 and 2500 ng/dL, inclusive, during the 168-hour dosing interval at Week 12. Cmax will be determined from serial serum testosterone measurements collected following dosing. The protocol-defined safety criterion is met if fewer than 5% of participants have Cmax within this range.
Time frame: Week 12 (0-168 hours after dosing)
Number of Participants With Maximum Serum Total Testosterone Concentration (Cmax) Above 2500 ng/dL at Week 12
The number of participants whose maximum serum total testosterone concentration (Cmax) exceeds 2500 ng/dL during the 168-hour dosing interval at Week 12. Cmax will be determined from serial serum testosterone measurements obtained following dosing. The protocol-defined safety criterion is met if no participants have Cmax above 2500 ng/dL.
Time frame: Week 12 (0-168 hours after dosing)
Number and Percentage of Participants With Minimum Serum Total Testosterone Concentration (Cmin) Below 300 ng/dL at Week 12
The number and percentage of participants whose minimum serum total testosterone concentration (Cmin) is below 300 ng/dL during the 168-hour dosing interval at Week 12. Cmin is defined as the lowest observed serum total testosterone concentration during the dosing interval and will be determined using serial pharmacokinetic blood samples.
Time frame: Week 12 (0-168 hours after dosing)
Percentage of Participants Receiving 75 mg With Average Serum Total Testosterone Concentration Within 300-1100 ng/dL at Week 12
The percentage of participants receiving the 75 mg testosterone cypionate auto-injector dose whose average serum total testosterone concentration (Cavg0-168h) is within 300-1100 ng/dL at Week 12. Cavg will be calculated as AUC0-168h divided by 168 hours. Participants receiving the 50 mg or 100 mg dose at Week 12 will be excluded from this analysis. The protocol-defined criterion is met if at least 75% of participants achieve the target range, with the lower bound of the 95% confidence interval at least 65%.
Time frame: Week 12 (0-168 hours after dosing)
Average Serum Total Testosterone Concentration (Cavg0-168h) in Participants Receiving 100 mg at Week 12
Average serum total testosterone concentration over the 168-hour dosing interval at Week 12 in participants receiving the 100 mg testosterone cypionate auto-injector dose. Cavg will be calculated as AUC0-168h divided by 168 hours and summarized using descriptive statistics, provided sufficient participants receive this dose.
Time frame: Week 12 (0-168 hours after dosing)
Average Serum Total Testosterone Concentration (Cavg0-168h) in Participants Receiving 50 mg at Week 12
Average serum total testosterone concentration over the 168-hour dosing interval at Week 12 in participants receiving the 50 mg testosterone cypionate auto-injector dose. Cavg will be calculated as AUC0-168h divided by 168 hours and summarized using descriptive statistics, provided sufficient participants receive this dose.
Time frame: Week 12 (0-168 hours after dosing)
Area Under the Serum Total Testosterone Concentration-Time Curve (AUC0-168h) Following the 75 mg Dose at Week 1
The area under the serum total testosterone concentration-time curve from 0 to 168 hours following administration of a single 75 mg subcutaneous dose of testosterone cypionate at Week 1. AUC0-168h represents total serum testosterone exposure over the 7-day dosing interval and will be calculated from serial pharmacokinetic blood samples.
Time frame: Week 1 (0-168 hours after the first dose)
Maximum Serum Total Testosterone Concentration (Cmax) Following the 75 mg Dose at Week 1
The maximum observed serum total testosterone concentration following administration of a single 75 mg subcutaneous dose of testosterone cypionate at Week 1. Cmax will be determined from serial pharmacokinetic blood samples collected over the 168-hour dosing interval.
Time frame: Week 1 (0-168 hours after the first dose)
Time to Maximum Serum Total Testosterone Concentration (Tmax) Following the 75 mg Dose at Week 1
The time required to reach the maximum observed serum total testosterone concentration following administration of a single 75 mg subcutaneous dose of testosterone cypionate at Week 1. Tmax will be determined from serial pharmacokinetic blood samples collected over the 168-hour dosing interval and expressed in hours.
Time frame: Week 1 (0-168 hours after the first dose)
Average Serum Total Testosterone Concentration (Cavg0-168h) Following the 75 mg Dose at Week 1
The average serum total testosterone concentration over the 168-hour dosing interval following administration of a single 75 mg subcutaneous dose of testosterone cypionate at Week 1. Cavg will be calculated by dividing AUC0-168h by 168 hours and expressed in ng/dL.
Time frame: Week 1 (0-168 hours after the first dose)
Plan to share: No
From the registry record's own update history. This site started tracking changes on Sep 25, 2026; for anything earlier, see the record history on ClinicalTrials.gov ↗
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Studies of the drug tested here: Testosterone 17 beta-cypionate