Recruiting

Magnesium Glycinate, Magnesium L-Threonate, Placebo

Sponsor:

UCLA

Code:

NCT07640685

Conditions

Athletic Performance

Recovery

Sleep

Eligibility Criteria

Sex: All

Age: 18 - 35

Healthy Volunteers: Accepted

Interventions

Magnesium glycinate

Magnesium L-threonate

Placebo

Study Details

Brief summary:

This randomized, double-blind, placebo-controlled trial will compare magnesium glycinate, magnesium L-threonate, and placebo in UCLA varsity athletes. Participants will complete a baseline monitoring period followed by 4 weeks of blinded nightly supplementation. WHOOP 4.0 data will be used to evaluate sleep efficiency, total sleep time, sleep consistency, heart rate variability, resting heart rate, and recovery metrics. Baseline and final testing will assess selected reaction and physical performance outcomes. The primary outcome is change in WHOOP-derived sleep efficiency from baseline week to final treatment week.

Conditions

Athletic Performance

Recovery

Sleep

Study ID

NCT07640685

Start date

Oct 5, 2026

Status verified date

Oct, 2026

Completion date

Jun, 2027

Anticipated

Primary completion date

May, 2027

Anticipated

Eligibility Criteria

Eligibility Criteria

Sex: All

Age: 18 - 35

Healthy Volunteers: Accepted

Inclusion Criteria:

  • Age 18-35 years.
  • Current NCAA Division I athlete at UCLA.
  • Actively participating in team training and/or competition.
  • Willing to wear a WHOOP 4.0 device continuously during the baseline and treatment periods of the study block.
  • Able to swallow oral capsules and follow supplement instructions.
  • Able and willing to complete daily REDCap surveys and weekly check-ins during the study block.
  • Fluent in English.
  • Able to provide informed consent.

Exclusion Criteria:

  • Known kidney disease or impaired renal function, assessed by participant-completed screening questions and review by the PI or designated study clinician. Screening asks about known kidney disease, reduced kidney function, dialysis, a history of abnormally high magnesium, and prior medical advice to avoid magnesium supplementation. A positive or uncertain response requires clinician review. If safety cannot be established from the questionnaire and participant interview alone, the athlete will not be enrolled. The study will not access medical records or perform research laboratory testing for this screening.
  • Current use of non-study magnesium supplements within the past 30 days or unwillingness to avoid non-study magnesium supplements during the study unless approved by the study clinician.
  • Diagnosed or treated sleep disorder likely to confound sleep outcomes, such as untreated or unstable insomnia, sleep apnea, or regular use of sleep medication expected to affect study outcomes.
  • Known difficulty swallowing capsules or history of choking.
  • Known allergy or sensitivity to magnesium or inactive capsule ingredients.
  • Known current pregnancy or breastfeeding, determined by participant self-report; no pregnancy testing is planned for this minimal-risk study. A participant who becomes pregnant or begins breastfeeding during the study will stop study product and notify the study team. Additional exclusionary circumstances include use of magnesium-containing laxatives or antacids during the study unless approved by the study clinician, or significant recent or planned changes in training load, diet, sleep medication, or recovery supplements that the investigator believes would confound interpretation.

Study Design

Enrollment

150 participants

Anticipated

Allocation

Randomized

Intervention Model

Parallel Assignment

Primary purpose

Other

Interventions and Outcome Measures

Arms

experimental: Magnesium Glycinate

Participants randomized to this arm will take exactly two blinded magnesium glycinate capsules nightly for 4 weeks (28 days). Each capsule is labeled to provide 120 mg elemental magnesium, for 240 mg by label claim nightly; the lot-specific assay reports 144 mg per capsule, for 288 mg by assay nightly. The capsules are clear/natural size 00-EL HPMC capsules containing white powder. Take the two capsules approximately 1 hour before intended bedtime, with food, while upright, and with at least 8 oz water. There is no study product during the 1-week baseline period.

experimental: Magnesium L-Threonate

Participants randomized to this arm will take exactly two blinded capsules containing 1 g Magtein (magnesium L-threonate) each nightly for 4 weeks (28 days), for 2 g Magtein nightly. This corresponds to 156 mg elemental magnesium nightly based on the linked raw-ingredient certificate of analysis reporting 7.8% magnesium. The capsules are clear/natural size 00-EL HPMC capsules containing white powder. Take the two capsules approximately 1 hour before intended bedtime, with food, while upright, and with at least 8 oz water. There is no study product during the 1-week baseline period.

placebo comparator: Placebo

Participants randomized to this arm will take exactly two matched placebo capsules nightly for 4 weeks (28 days). Each capsule contains calcium laurate 300 mg plus silicified microcrystalline cellulose 440 mg and no active magnesium. The capsules are clear/natural size 00-EL HPMC capsules containing white powder. Take the two capsules approximately 1 hour before intended bedtime, with food, while upright, and with at least 8 oz water. There is no study product during the 1-week baseline period. The study uses one matched-placebo regimen and no double-dummy design.

Interventions

Magnesium glycinate

Blinded oral magnesium glycinate, exactly two capsules nightly for 28 days. The nightly dose is 240 mg elemental magnesium by label claim (120 mg per capsule) and 288 mg by lot-specific assay (144 mg per capsule). Take approximately 1 hour before intended bedtime, with food, while upright, and with at least 8 oz water. No study product is taken during the 1-week baseline period.

Magnesium L-threonate

Blinded oral magnesium L-threonate (Magtein), exactly two 1-g capsules nightly for 28 days, for 2 g Magtein and 156 mg elemental magnesium nightly based on the linked raw-ingredient assay of 7.8% magnesium. Take approximately 1 hour before intended bedtime, with food, while upright, and with at least 8 oz water. No study product is taken during the 1-week baseline period.

Placebo

Matched oral placebo, exactly two capsules nightly for 28 days. Each capsule contains calcium laurate 300 mg plus silicified microcrystalline cellulose 440 mg and no active magnesium. Take approximately 1 hour before intended bedtime, with food, while upright, and with at least 8 oz water. No study product is taken during the 1-week baseline period. One matched-placebo regimen is used, without double-dummy.

Primary outcome measure

  • Change in WHOOP-derived sleep efficiency percentage from baseline week to final treatment week [ Time Frame: Baseline week to final treatment week, approximately 5 weeks total including baseline monitoring ]

Central Contacts and Locations

Central contacts

Jeremy Swisher, MD

936-520-3595jswisher@mednet.ucla.edu

Kimberly Burbank, MD

kburbank@mednet.ucla.edu

Locations

University of California, Los Angeles

Recruiting

Los Angeles, California, United States, 90095

Contacts

Jeremy Swisher, MD

936-520-3595jswisher@mednet.ucla.edu

Kimberly Burbank, MD

kburbank@mednet.ucla.edu

More Information

Sponsor

University of California, Los Angeles

Last update posted

Oct 15, 2026

Last verified

Oct, 2026

Keywords

  • magnesium glycinate
  • magnesium L-threonate
  • collegiate athletes
  • sleep duration
  • athlete recovery
  • WHOOP
  • heart rate variability
  • reaction time
  • placebo-controlled trial
  • dietary supplement

Trial information was received from ClinicalTrials.gov and was last updated on 2026-10-16. This information was provided to ClinicalTrials.gov by University of California, Los Angeles on 2026-10-15. Recruitment status is synced daily from ClinicalTrials.gov and may not reflect the sponsor's current status. Confirm during your call.