An interventional study of protein supplement and Placebo in Muscle Atrophy, sponsored by Sam Houston State University. Recruiting at 2 sites in United States. Open to female participants aged 18 Years to 35 Years, including healthy volunteers. Per ClinicalTrials.gov, last updated 2026-09-25.
Sponsored by Sam Houston State University · Not applicable, Interventional, and Treatment
The purpose of this research is to determine if increasing 12% of daily protein intake during the luteal phase mitigates the potential catabolic effects of progesterone on skeletal muscle. We anticipate there will be an advantageous, decreased catabolic effect with increasing protein intake during the luteal phase.
By doing this study, we hope to learn if millions of women would benefit from additional protein supplementation during the luteal phase, which may lead to decreased skeletal muscle atrophy over time. Your participation in this research will last about 4 months.
The physiologic effects of the female menstrual cycle have been shown to cause many changes to metabolic processes throughout the body depending on the phase of the cycle. For example, during the follicular phase, increase in estrogen aids in arterial vasodilation, lipid metabolism, neuroprotection, and maintaining bone density (Gruber et al. 2002). During the luteal phase, the increase in progesterone aids in thermoregulation, increased respiration, and basal insulin levels (Taraborrelli 2015). However, there is conflicting evidence regarding net progesterone effects on skeletal muscle. Some studies state that progesterone has an anabolic effect while others suggest the contrary. Despite the discrepancies with current literature, Sims et al. recommends female athletes increase their protein intake by 12% during the luteal phase of their menstrual cycle to potentially counteract the protein catabolic effects of progesterone on skeletal muscle (2023). The basis of this conclusion was based on invitro and in vivo studies showing decreases amino acids during the luteal phase (Faustmann et al. 2018 \& Draper et al. 2018)
To our knowledge, no study exists that analyzes protein degradation with protein supplementation increase during the luteal phase. The purpose of this research is to determine if increasing 12% of daily protein intake during the luteal phase mitigates the potential catabolic effects of progesterone on skeletal muscle. This research could help determine if millions of women would benefit from additional protein supplementation during the luteal phase, which may lead to decreased skeletal muscle atrophy over time. We anticipate there will be an advantageous, decreased catabolic effect with increasing protein intake during the luteal phase.
412 studies on the registry are indexed under Muscular Atrophy; 77 are open to participants now.
This study's planned enrollment of 34 is below the median of 40 across 326 interventional studies indexed under Muscular Atrophy.
Browse Muscular Atrophy studies →Sam Houston State University is the lead sponsor of 11 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.
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.
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.
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.
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.
Will receive protein supplement
Dietary Supplement: protein supplement
Will receive placebo supplement
Dietary Supplement: Placebo
Protein supplementation during progesterone peak to stop protein degradation effect.
Also known as: A
Will receive placebo supplementation
Also known as: B
Skeletal Muscle Protein Degradation
Primary outcomes will be changes in urinary N-fragment of titin and serum 3-methylhistidine between supplementation and placebo conditions. Paired t-tests or linear mixed-effects models will be used to account for within-subject crossover effects. Hormone levels will be included as covariates. Statistical significance will be set at p \< 0.05.
Time frame: 48 hours
Decrease protein degradation
We would like to home in on protein intake and degradation to quantify the amount of protein loss seen during the luteal phase, the point at which protein degradation is deemed to be the highest. Our specific aims for this project will be to 1) quantify protein degradation at the time of the luteal phase and 2) determine whether targeted protein supplementation during the luteal phase will reduce measured protein degradation. We anticipate there will be an advantageous, decreased catabolic effect with increasing protein intake during the luteal phase. To measure this, we will use Blood and Urine samples during the menstrual cycle. Blood Samples: Blood will be collected in serum separator tubes (SST) Serum will be analyzed using enzyme-linked immunosorbent assay (ELISA) methods to measure: 3-Methylhistidine Progesterone Urine Samples: Urine samples will be analyzed using ELISA methods to measure: N-fragment of Titin Creatin
Time frame: 48 hours
Plan to share: Undecided
Started Aug 2026 (actual). Primary completion is estimated for Dec 2026, 4 months after the start.
Of 168 non-industry interventional studies with no phase under Muscular Atrophy, half reached primary completion within 22 months of starting (the median), counting those still running; a quarter within 9 and three quarters within 41. This study's planned 4 months is below that.
Counting every sponsor, half of 174 studies reached it within 22 months; a quarter within 9 and three quarters within 37.
How these figures are worked out, and which studies are left out of them.
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 ↗
Eligibility is decided by the study team. Share this record with your doctor or contact the team directly.
Contact study teamGet an email when the registry record changes — status, dates, results — or when someone posts here.
Sign in to followQuestions and observations about this study, from anyone following it. Not medical advice, and not a channel to the study team — their contact details are on the registry record.
Sign in to join the discussion. Reading takes no account; posting does. You choose a display name, and a pseudonym is the default.
Nothing here yet. If you are running this trial, taking part in it, or weighing whether to, this is the place to say so.
Studies of the drug tested here: Protein Supplement
Sam Houston State University