What this study is
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.
What's being tested
- Magnesium glycinate
Intervention · DIETARY SUPPLEMENT
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
Intervention · DIETARY SUPPLEMENT
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
Intervention · OTHER
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.
Study details
- Official title
- Effects of Magnesium Glycinate and Magnesium L-Threonate on Sleep, Recovery, and Performance in Collegiate Athletes
- Sponsor
- University of California, Los Angeles
- Conditions
- Athletic Performance · Recovery · Sleep
- Enrolling
- 150 people
- Starts
- 2026-10-05
- Est. completion
- 2027-06
- Design
- Quadruple-blind, randomized, parallel groups
- Record
- View on ClinicalTrials.gov ↗
Who can join
Age 18 Years – 35 YearsSex ALLHealthy volunteers AcceptedYou may qualify if
- 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.
You can't join if
- 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.
Sign in and we'll check these against your records.Full criteria on ClinicalTrials.gov ↗
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Study locations (1)
1 openUniversity of California, Los Angeles
Los Angeles, California, United States
- Jeremy Swisher, MD · Contact936-520-3595jswisher@mednet.ucla.edu
- Kimberly Burbank, MD · Contactkburbank@mednet.ucla.edu
Recruiting
Study team
Sponsor
University of California, Los Angeles
Study ID IRB-26-1185
Principal investigator
Jeremy Swisher, MD
University of California, Los Angeles
Study director
Joshua Goldman, MD
University of California, Los Angeles
Frequently asked questions
The sponsor hasn't published answers to common questions for this trial.