Skeletal Muscle PerformanceNCT05604586
Assessment of the Impact of N-acetylcysteine Supplementation on Physical Performance
A study testing N-acetylcysteine in people with Skeletal Muscle Performance and Gene Polymorphisms, run by Poznan University of Life Sciences at 1 site in Poland.
Trial summary
Study aims to verify the hypothesis: N-acetylcysteine (NAC) supplementation improves exercise capacity in people training endurance sports and the effectiveness of this supplementation depends on the polymorphism of genes related to folate and glutathione metabolism. Read more about this study
- Who is it for?
- Ages 18 to 45 yearsHealthy volunteers can take part
- Conditions the study is for
- Skeletal Muscle Performance, Gene Polymorphisms
- What is being tested?
- N-acetylcysteine
- Type of treatment
- Pill or oral medicine
- Could I receive a placebo?
- Yes, some participants may receive a placebo
- How many people
- 77 participants
- Where
- 1 sitePoland
- Study dates
- 1 May 2022to 30 Sep 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 45 years
- All sexes
- Healthy volunteers accepted
- Adult
Who may be able to join
- Consent to participate in the study and acceptance of the established scheme for conducting the intervention
- age range between 18 and 45 years old
- regular training with a frequency of at least 3 times a week during the last year,
Who cannot join
- no consent to participate in the study and no acceptance of the established scheme of the conducted intervention
- existing diseases of the blood system and neoplastic diseases
- respiratory system diseases
- obesity
- any medical contraindications to exercise
- Results obtained from exercise tests that do not meet the inclusion criteria
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- use of NAC during the last month
- allergy to NAC
- smoking
- pregnancy and lactation
Trial locations and contacts
1 site in 1 country.
About this study
Official title: Assessment of the Impact of N-acetylcysteine Supplementation on Physical Performance Depending on the Polymorphism of Genes Related to Glutathione Metabolism
Study aims to verify the hypothesis:
- N-acetylcysteine (NAC) supplementation improves exercise capacity in people training endurance sports and the effectiveness of this supplementation depends on the polymorphism of genes related to folate and glutathione metabolism.
- NAC supplementation affects the parameters of oxidative stress among women and men training endurance disciplines
Read the detailed description
- Glutathione depletion caused by a combination of intense physical exertion associated with the generation of significant amounts of reactive oxygen species (ROS), and possibly with having an unfavorable variant of the methylenetetrahydrofolate reductase (MTHFR), glutamate-cysteine ligase catalytic subunit (GCLC); glutamate-cysteine ligase modifier subunit (GCLM); glutathione S-transferase Pi 1 (GSTP1); glutathione synthetase (GSS) or cystathionine-β-synthase (CBS) genes may contribute to lower adaptation to exercise, but also to deterioration of health of people training endurance sports.
- The main objective of the study is to verify the hypothesis that NAC supplementation has a beneficial effect on regeneration between intense exercise tests simulating a race characteristic for a given discipline. In addition, this study is aimed at checking whether genotype may modify the effectiveness of the supplementation measured as exercise and biochemical parameters . A double-blind study involving 100 women and men supplementing 1200 mg of N-acetylcysteine daily or 1200 mg of rice flour in three equal doses. Supplementation will last for 7 days. Blood sampling and body composition testing will be performed in the morning of the exercise test day. Discipline-specific exercise testing will be performed before and after the intervention.
- Conditions
- Skeletal Muscle Performance, Gene Polymorphisms
- Being tested
- N-acetylcysteine, Placebo
- Keywords
- Sport performance, gene polymorphism, N-acetylcysteine
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
N-acetylcysteineDietary supplement
100 women and men supplementing 1200 mg of N-acetylcysteine daily in three equal doses. Supplementation will last for 7 days.
PlaceboDietary supplement
100 women and men supplementing 1200 mg of placebo daily in three equal doses. Supplementation will last for 7 days.
| Study group | Role | What they receive |
|---|---|---|
| N-acetylcysteine | Experimental | Intervention: Dietary Supplement: N-acetylcysteine Participants will undergo two exercise tests and daily supplementation with N-acetylcysteine orally in three doses a day for seven consecutive days. Receives: Dietary Supplement: N-acetylcysteine |
| Placebo | Placebo comparator | Supplement: Placebo Participants will undergo two exercise tests and daily supplementation with placebo orally in three doses a day for seven consecutive days. Receives: Dietary Supplement: Placebo |
What is being measured
The primary outcome is the main question the study is designed to answer.
Assesment of change in results of time trial test
(min/test) change within groups and between groups
Measured: Baseline,1 week
Secondary outcomes (18)
Reduced glutathione (GSH)
GSH (µM) concentrations change within the group and between the groups
Measured: Baseline,1 week
Oxidized glutathione (GSSG)
GSSG (µM) concentrations change within the group and between the groups
Measured: Baseline,1 week
Homocysteine (Hcy)
Hcy (µmol/l) concentrations change within the group and between the groups
Measured: Baseline,1 week
Total cholesterol (TChol)
TChol (mg/dl) concentrations change within the group and between the groups
Measured: Baseline,1 week
Blood HDL-cholesterol (HDL-C)
HDL-C (mg/dl) concentrations change within the group and between the groups
Measured: Baseline,1 week
Blood LDL-cholesterol (LDL-C)
LDL-C (mg/dl) concentrations change within the group and between the groups
Measured: 1 week
Blood triacylglycerol (TAG)
TAG (mg/dl) concentrations change within the group and between the groups
Measured: Baseline,1 week
Dietary intake
macro and micronutrient intake (g,mg,ug)
Measured: Baseline,1 week
aspartate aminotransferase (ASPAT)
ASPAT [U/l] Changes within groups and between groups
Measured: 1 week
Alanine transaminase (ALAT)
ALAT [U/l] change within groups and between groups
Measured: Baseline,1 week
Oxygen volume (VO2)
VO2 (ml/kg bw./min) change within groups and between groups
Measured: Baseline,1 week
Carbon dioxide volume (VCO2)
VCO2 (ml/kgm.c./min) change within groups and between groups
Measured: Baseline,1 week
Testosterone (T)
T (ng/dL) concentrations change within the group and between the groups
Measured: Baseline,1 week
Cortisol (C)
C (ng/dL) concentrations change within the group and between the groups
Measured: Baseline,1 week
Body mass(BM)
Change in BM (kg) within groups and between groups
Measured: Baseline, 1 week
Fat Free Mass (FFM)
FFM change within (kg) groups and between groups
Measured: Baseline, 1 week
Fat Mass% (FM%)
FM% change within groups and between groups
Measured: Baseline, 1 week
Thiobarbituric Acid Reactive Species (TBARS)
TBARS concentrations change within the group and between the groups
Measured: 1 week
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted3 Nov 2022
- Study start1 May 2022
- Primary completion15 Mar 2025
- Study completion30 Sep 2025
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Skeletal Muscle PerformanceStudies 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
- Crossover
- Model description
- Eligible volunteers will be randomly assigned to one of the research groups. One of the groups will be taking the supplement for a period of 7 days, while the other group will be taking a placebo. Then a 3 week washout period will be performed. After that the groups will be exchanged and each participant will be assigned to a different group than it was in the first period of the study.
- Masking
- Double blind
- Who is masked
- Participant, Investigator
- Enrolment
- 77 participants (actual)
Sponsor and investigators
- Lead sponsor
- Poznan University of Life Sciences
- Sponsor type
- University, hospital or other
- Responsible party
- Sponsor
- Investigators
- Marcin Sadowski, MSc, Principal investigator, Poznań University of Life Science
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT05604586
- Sponsor's protocol ID
- NAC/29112021
- Status last verified
- Jul 2024
- First submitted
- 7 Jul 2022
- Last updated
- 10 Jun 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No
Study at a glance
From the registry record, last updated by the sponsor on 10 Jun 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Assessment of the Impact of N-acetylcysteine Supplementation on Physical Performance Depending on the Polymorphism of Genes Related to Glutathione Metabolism
- ClinicalTrials.gov ID
- NCT05604586
- Acronym / sponsor ID
- NAC/29112021
- Conditions
- Skeletal Muscle Performance, Gene Polymorphisms
- Keywords
- Sport performance, gene polymorphism, N-acetylcysteine
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 77 participants (actual)
- Lead sponsor
- Poznan University of Life SciencesUniversity, hospital or other
- Study start
- 1 May 2022 (actual)
- Primary completion
- 15 Mar 2025 (actual)
- Study completion
- 30 Sep 2025 (actual)
- First posted
- 3 Nov 2022 (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.
Study aims to verify the hypothesis:
- N-acetylcysteine (NAC) supplementation improves exercise capacity in people training endurance sports and the effectiveness of this supplementation depends on the polymorphism of genes related to folate and glutathione metabolism.
- NAC supplementation affects the parameters of oxidative stress among women and men training endurance disciplines
Detailed description
- Glutathione depletion caused by a combination of intense physical exertion associated with the generation of significant amounts of reactive oxygen species (ROS), and possibly with having an unfavorable variant of the methylenetetrahydrofolate reductase (MTHFR), glutamate-cysteine ligase catalytic subunit (GCLC); glutamate-cysteine ligase modifier subunit (GCLM); glutathione S-transferase Pi 1 (GSTP1); glutathione synthetase (GSS) or cystathionine-β-synthase (CBS) genes may contribute to lower adaptation to exercise, but also to deterioration of health of people training endurance sports.
- The main objective of the study is to verify the hypothesis that NAC supplementation has a beneficial effect on regeneration between intense exercise tests simulating a race characteristic for a given discipline. In addition, this study is aimed at checking whether genotype may modify the effectiveness of the supplementation measured as exercise and biochemical parameters . A double-blind study involving 100 women and men supplementing 1200 mg of N-acetylcysteine daily or 1200 mg of rice flour in three equal doses. Supplementation will last for 7 days. Blood sampling and body composition testing will be performed in the morning of the exercise test day. Discipline-specific exercise testing will be performed before and after the intervention.
Study design
- Primary purpose
- Basic science
- Allocation
- Randomised
- Intervention model
- Crossover
- Masking
- Double blind (participant, investigator)
- Number of arms
- 2
- Model description
- Eligible volunteers will be randomly assigned to one of the research groups. One of the groups will be taking the supplement for a period of 7 days, while the other group will be taking a placebo. Then a 3 week washout period will be performed. After that the groups will be exchanged and each participant will be assigned to a different group than it was in the first period of the study.
| Arm | Type | Receives |
|---|---|---|
| N-acetylcysteine | Experimental | Dietary Supplement: N-acetylcysteineIntervention: Dietary Supplement: N-acetylcysteine Participants will undergo two exercise tests and daily supplementation with N-acetylcysteine orally in three doses a day for seven consecutive days. |
| Placebo | Placebo comparator | Dietary Supplement: PlaceboSupplement: Placebo Participants will undergo two exercise tests and daily supplementation with placebo orally in three doses a day for seven consecutive days. |
Who may qualify
- Ages
- 18 to 45 years
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Adult
Key inclusion criteria (3 listed)
- Consent to participate in the study and acceptance of the established scheme for conducting the intervention
- age range between 18 and 45 years old
- regular training with a frequency of at least 3 times a week during the last year,
Key exclusion criteria (10 listed)
- no consent to participate in the study and no acceptance of the established scheme of the conducted intervention
- existing diseases of the blood system and neoplastic diseases
- respiratory system diseases
- obesity
- any medical contraindications to exercise
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 |
|---|---|---|
| N-acetylcysteine100 women and men supplementing 1200 mg of N-acetylcysteine daily in three equal doses. Supplementation will last for 7 days. | Dietary supplement | N-acetylcysteine |
| Placebo100 women and men supplementing 1200 mg of placebo daily in three equal doses. Supplementation will last for 7 days. | Dietary supplement | Placebo |
Primary outcome
Assesment of change in results of time trial test
Time frame: Baseline,1 week
(min/test) change within groups and between groups
18 secondary outcomes
Reduced glutathione (GSH)
Time frame: Baseline,1 week
Oxidized glutathione (GSSG)
Time frame: Baseline,1 week
Homocysteine (Hcy)
Time frame: Baseline,1 week
Total cholesterol (TChol)
Time frame: Baseline,1 week
Blood HDL-cholesterol (HDL-C)
Time frame: Baseline,1 week
Blood LDL-cholesterol (LDL-C)
Time frame: 1 week
Blood triacylglycerol (TAG)
Time frame: Baseline,1 week
Dietary intake
Time frame: Baseline,1 week
aspartate aminotransferase (ASPAT)
Time frame: 1 week
Alanine transaminase (ALAT)
Time frame: Baseline,1 week
Oxygen volume (VO2)
Time frame: Baseline,1 week
Carbon dioxide volume (VCO2)
Time frame: Baseline,1 week
Testosterone (T)
Time frame: Baseline,1 week
Cortisol (C)
Time frame: Baseline,1 week
Body mass(BM)
Time frame: Baseline, 1 week
Fat Free Mass (FFM)
Time frame: Baseline, 1 week
Fat Mass% (FM%)
Time frame: Baseline, 1 week
Thiobarbituric Acid Reactive Species (TBARS)
Time frame: 1 week
Results and safety
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 10 Jun 2026.
- Individual participant dataSharing planned: No
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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.
Marcin Sadowski, MSc principal investigator
Poznań University of Life Science
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing N-acetylcysteine in people with Skeletal Muscle Performance and Gene Polymorphisms, run by Poznan University of Life Sciences at 1 site in Poland.
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 3 inclusion and 10 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: finished, as of the sponsor's last update on 10 Jun 2026. 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 Poland. 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?
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Assesment of change in results of time trial test (time frame: Baseline,1 week). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
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 10 Jun 2026.