An interventional study of Testosterone Undecanoate in Skeletal Muscle Physiology, sponsored by Morten Hostrup, PhD. Recruiting at 1 site in Denmark. Open to male participants aged 18 Years to 40 Years, including healthy volunteers. Per ClinicalTrials.gov, last updated 2025-04-10.
Sponsored by Morten Hostrup, PhD · Not applicable, Interventional, and Basic science
The purpose of this project is to investigate underlying mechanisms of testosterone- and resistance training-induced muscle hypertrophy and muscle memory in humans.
Morten Hostrup, PhD is the lead sponsor of 17 studies on the registry; 7 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.
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.
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.
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.
Participants are randomized to a single injection of 1000 mg testosterone undecanoate
Drug: Testosterone Undecanoate
Participants are randomized to a single placebo injection
Drug: Testosterone Undecanoate
Following testosterone/placebo injection, participants undergo supervised resistance training for 4 weeks. This period is followed by a washout period with no drug and either continued resistance training or detraining for 16 weeks. Thereafter, another 4-week period with supervised resistance training is commenced, with no drug.
Fiber cross-sectional area
Immunohistochemistry to determine fiber cross-sectional area
Time frame: The change in fiber cross-sectional is assessed at baseline, 4, 20 and 24 weeks
Myonuclei
Immunohistochemistry to determine number of myonuclei
Time frame: The change in myonuclei is assessed at baseline, 4, 20 and 24 weeks
Skeletal muscle proteome
Pathway enrichment analysis of the muscle proteome using mass spectrometry-based proteomics
Time frame: The change in the muscle proteome is assessed at baseline, 4, 20 and 24 weeks
Lean mass
Lean mass assessed by dual X-ray absorptiometry (DXA)
Time frame: The change in lean mass is assessed at baseline, 4, 20 and 24 weeks
Satellite cells
Immunohistochemistry to determine number of satellite cells
Time frame: The change in satellite cells is assessed at baseline, 4, 20 and 24 weeks
Muscle strength
1-repetition maximum
Time frame: The change in 1-repetition maximum is assessed at baseline, 4, 20 and 24 weeks
Plan to share: Undecided
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Studies of the drug tested here: Testosterone undecanoate
Morten Hostrup, PhD