Skeletal Muscle PhysiologyNCT05692856
Muscle Memory After Treatment With Anabolic Substance Clenbuterol and Resistance Training in Humans
A study testing Clenbuterol in people with Skeletal Muscle Physiology, run by Morten Hostrup, PhD at 1 site in Denmark.
Trial summary
The purpose of the project is investigate muscle memory and underlying mechanisms in humans following resistance training and use of the anabolic substance clenbuterol. Read more about this study
- Who is it for?
- Ages 18 to 40 yearsHealthy volunteers can take part
- Conditions the study is for
- Skeletal Muscle Physiology
- What is being tested?
- Clenbuterol
- Type of treatment
- Pill or oral medicine
- Could I receive a placebo?
- Yes, some participants may receive a placebo
- How many people
- 60 participants
- Where
- 1 siteDenmark
- Study dates
- 1 Feb 2023to 1 Aug 2025
- Phase
- Interventional
- 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 18 to 40 years
- All sexes
- Healthy volunteers accepted
- Adult
Who may be able to join
- Healthy men and women
- BMI of <26 and normal ECG and blood pressure
Who cannot join
- Smoking
- Chronic disease,
- Use of prescription medication
- Pain due to current or previous musculoskeletal injury
- Resistance training more than once per week in the 12 months leading up to the intervention
- Current or previous use of prohibited anabolic substances
Trial locations and contacts
1 site in 1 country.
Denmark1 site, 1 recruiting
- Recruiting
August Krogh Building
Copenhagen, 2100
Morten Hostrup, +4535321595, mhostrup@nexs.ku.dk
Lukas Moesgaard, MSc
About this study
Official title: Muscle Memory After Treatment With Anabolic Substance Clenbuterol and Resistance Training in Humans: Myonuclear Addition, Hypertrophy and Myocellular Reprogramming
The purpose of the project is investigate muscle memory and underlying mechanisms in humans following resistance training and use of the anabolic substance clenbuterol.
- Conditions
- Skeletal Muscle Physiology
- Being tested
- Clenbuterol, Placebo
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
ClenbuterolDrug
Participants ingest 80 micrograms clenbuterol daily during the initial 8-week period. This period is followed by a washout of 16 weeks with no drug and resistance training. Thereafter, an 8-week period with supervised resistance training is commenced, with no drug.
PlaceboDrug
Participants ingest placebo tablets daily during the initial 8-week period. This period is followed by a washout of 16 weeks with no drug and resistance training. Thereafter, an 8-week period with supervised resistance training is commenced, with no drug.
| Study group | Role | What they receive |
|---|---|---|
| Clenbuterol | Experimental | Participants are randomized to daily ingestion of clenbuterol for a period of 8 weeks, with or without supervised resistance training. Receives: Drug: Clenbuterol |
| Placebo | Placebo comparator | Participants are randomized to daily ingestion of placebo for a period of 8 weeks, with or without supervised resistance training. Receives: Drug: Placebo |
What is being measured
The primary outcome is the main question the study is designed to answer.
Fiber cross-sectional area
Immunohistochemistry to determine fiber cross-sectional area
Measured: The change in fiber cross-sectional is assessed at baseline, 8, 24 and 32 weeks
Myonuclei
Immunohistochemistry to determine number of myonuclei
Measured: The change in myonuclei is assessed at baseline, 8, 24 and 32 weeks
Skeletal muscle proteome
Pathway enrichment analysis of the muscle proteome using mass-spectrometry based proteomics
Measured: The change in the muscle proteome is assessed at baseline, 8, 24 and 32 weeks
Secondary outcomes (5)
Lean mass
Lean mass assessed by dual X-ray absorptiometry (DXA)
Measured: The change in lean mass is assessed at baseline, 8, 24 and 32 weeks
Isometric muscle strength
Maximal voluntary isometric contraction of m. quadriceps
Measured: The change in maximal voluntary isometric contraction is assessed at baseline, 8, 24 and 32 weeks
Dynamic muscle strength
1-repetition maximum
Measured: The change in 1-repetition maximum is assessed at baseline, 8, 24 and 32 weeks
Sprint performance
Work performed (W) during a sprint on a bicycle ergometer
Measured: The change in sprint performance is assessed at baseline, 8, 24 and 32 weeks
Satellite cells
Immunohistochemistry to determine number of satellite cells
Measured: The change in satellite cells is assessed at baseline, 8, 24 and 32 weeks
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted20 Jan 2023
- Study start1 Feb 2023 (estimated)
- Primary completion1 Dec 2024 (estimated)
- Study completion1 Aug 2025 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Publications (1)Papers the sponsor has linked to this study.
- Other trials for Skeletal Muscle PhysiologyStudies 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 N/A
- Primary purpose
- Basic science
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Quadruple blind
- Who is masked
- Participant, Care provider, Investigator, Outcomes assessor
- Enrolment
- 60 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Morten Hostrup, PhD
- Sponsor type
- University, hospital or other
- Responsible party
- Sponsor-investigator, Morten Hostrup, PhD, University of Copenhagen
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT05692856
- Sponsor's protocol ID
- CLEN-MEM
- Status last verified
- Jan 2023
- First submitted
- 23 Dec 2022
- Last updated
- 20 Jan 2023
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- Undecided
Publications
Moesgaard L, Uhrenholt SS, Jessen S, Hasgaard RB, Backer V, Dehnes Y, Bangsbo J, Hostrup M. Effects of Clenbuterol on Body Composition and Strength Following Resistance Training, Detraining, and Retraining in Healthy Adults: A Randomized Controlled Trial. Sports Med. 2026 Sep 12. doi: 10.1007/s40279-026-02522-4. Online ahead of print.
PubMed 42730843
Study at a glance
From the registry record, last updated by the sponsor on 20 Jan 2023. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Muscle Memory After Treatment With Anabolic Substance Clenbuterol and Resistance Training in Humans: Myonuclear Addition, Hypertrophy and Myocellular Reprogramming
- ClinicalTrials.gov ID
- NCT05692856
- Acronym / sponsor ID
- CLEN-MEM
- Conditions
- Skeletal Muscle Physiology
- Study type
- Interventional
- Recruitment status
- Unknown status
- Enrolment
- 60 participants (estimated)
- Lead sponsor
- Morten Hostrup, PhDUniversity, hospital or other
- Study start
- 1 Feb 2023 (estimated)
- Primary completion
- 1 Dec 2024 (estimated)
- Study completion
- 1 Aug 2025 (estimated)
- First posted
- 20 Jan 2023 (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.
The purpose of the project is investigate muscle memory and underlying mechanisms in humans following resistance training and use of the anabolic substance clenbuterol.
Study design
- Primary purpose
- Basic science
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Quadruple blind (participant, care provider, investigator, outcomes assessor)
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| Clenbuterol | Experimental | Drug: ClenbuterolParticipants are randomized to daily ingestion of clenbuterol for a period of 8 weeks, with or without supervised resistance training. |
| Placebo | Placebo comparator | Drug: PlaceboParticipants are randomized to daily ingestion of placebo for a period of 8 weeks, with or without supervised resistance training. |
Who may qualify
- Ages
- 18 to 40 years
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Adult
Key inclusion criteria (2 listed)
- Healthy men and women
- BMI of <26 and normal ECG and blood pressure
Key exclusion criteria (6 listed)
- Smoking
- Chronic disease,
- Use of prescription medication
- Pain due to current or previous musculoskeletal injury
- Resistance training more than once per week in the 12 months leading up to the intervention
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 |
|---|---|---|
| ClenbuterolParticipants ingest 80 micrograms clenbuterol daily during the initial 8-week period. This period is followed by a washout of 16 weeks with no drug and resistance training. Thereafter, an 8-week period with supervised resistance training is commenced, with no drug. | Drug | Clenbuterol |
| PlaceboParticipants ingest placebo tablets daily during the initial 8-week period. This period is followed by a washout of 16 weeks with no drug and resistance training. Thereafter, an 8-week period with supervised resistance training is commenced, with no drug. | Drug | Placebo |
Primary outcome
Fiber cross-sectional area
Time frame: The change in fiber cross-sectional is assessed at baseline, 8, 24 and 32 weeks
Immunohistochemistry to determine fiber cross-sectional area
Myonuclei
Time frame: The change in myonuclei is assessed at baseline, 8, 24 and 32 weeks
Immunohistochemistry to determine number of myonuclei
Skeletal muscle proteome
Time frame: The change in the muscle proteome is assessed at baseline, 8, 24 and 32 weeks
Pathway enrichment analysis of the muscle proteome using mass-spectrometry based proteomics
5 secondary outcomes
Lean mass
Time frame: The change in lean mass is assessed at baseline, 8, 24 and 32 weeks
Isometric muscle strength
Time frame: The change in maximal voluntary isometric contraction is assessed at baseline, 8, 24 and 32 weeks
Dynamic muscle strength
Time frame: The change in 1-repetition maximum is assessed at baseline, 8, 24 and 32 weeks
Sprint performance
Time frame: The change in sprint performance is assessed at baseline, 8, 24 and 32 weeks
Satellite cells
Time frame: The change in satellite cells is assessed at baseline, 8, 24 and 32 weeks
Results and safety
Results are not available in the source record.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 20 Jan 2023.
- Derived from this study: PubMed 42730843Moesgaard L, Uhrenholt SS, Jessen S, Hasgaard RB, Backer V, Dehnes Y, Bangsbo J, Hostrup M. Effects of Clenbuterol on Body Composition and Strength Following Resistance Training, Detraining, and Retraining in Healthy Adults: A Randomized Controlled Trial. Sports Med. 2026 Sep 12. doi: 10.1007/s40279-026-02522-4. Online ahead of print.
- Individual participant dataSharing planned: Undecided
Related trials for Skeletal Muscle Physiology
Recruiting
Preserving Muscle Mass During Incretin-Induced Weight Loss
Obesity (BMI > 35)
Active, not recruitingObservational study
Skeletal Muscle Biomarkers in People With Fragile Sarcolemmal Muscular Dystrophy
Genetic Disorder
Active, not recruitingPhase 2
GRK-Biased Activation Via β2-Adrenergic Receptors in Human Skeletal Muscle
Overweight and Obesity
Recruiting
Long-term Effects of Endobronchial Valve Implantation on Cardiac Function and Skeletal Muscle Function
Chronic Obstructive Pulmonary Disease
RecruitingPhase 1
: Vascular Function in Health and Disease
Chronic Obstructive Pulmonary Disease, Pulmonary Artery Hypertension
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.
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing Clenbuterol in people with Skeletal Muscle Physiology, run by Morten Hostrup, PhD at 1 site in Denmark.
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 2 inclusion and 6 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: status not confirmed, as of the sponsor's last update on 20 Jan 2023. 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 Denmark. 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. Some participants in this study may receive a placebo. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
Results are not available in the source record.
How can a doctor refer a patient or contact the research team?
Contact Morten Hostrup (+4535321595, mhostrup@nexs.ku.dk), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Fiber cross-sectional area (time frame: The change in fiber cross-sectional is assessed at baseline, 8, 24 and 32 weeks). 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?
On the ClinicalTrials.gov record for NCT05692856, which also lists 1 linked publication.
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 20 Jan 2023.