References & Studies

The peer-reviewed research behind every SQ[1] formula.

We built SQ[1] around the published literature on nutrition during rapid weight loss. Below is the research we relied on — grouped by product, with links to the original studies so you can read them yourself.

Why GLP-1 body composition matters

Published analyses of GLP-1 and incretin-based weight-loss trials estimate that roughly 25–40% of the weight lost is fat-free mass. These two references anchor SQ[1]’s formulation philosophy.

New England Journal of Medicine · 2021

Once-Weekly Semaglutide in Adults with Overweight or Obesity (STEP 1)

PMID: 33567185 · DOI: 10.1056/NEJMoa2032183

The Lancet Diabetes & Endocrinology · 2024

Muscle matters: the effects of medically induced weight loss on skeletal muscle

PMID: 38796552 · DOI: 10.1016/S2213-8587(24)00272-9

SQ[1] Protect

Whey protein isolate, creatine, and HMB — studied for their role in supporting muscle maintenance during rapid weight loss.

Higher compared with lower dietary protein during an energy deficit combined with intense exercise promotes greater lean mass gain and fat mass loss: a randomized trial

Longland TM, Oikawa SY, Mitchell CJ, Devries MC, Phillips SM. · American Journal of Clinical Nutrition · 2016

40 young men in a 40% energy deficit over 4 weeks: the higher-protein group (2.4 g/kg/day) gained 1.2 kg of lean mass and lost 4.8 kg of fat while the lower-protein group (1.2 g/kg/day) essentially maintained lean mass — supporting the role of elevated protein intake during caloric deficit.

PMID: 26817506 · DOI: 10.3945/ajcn.115.119339Read study →

HMB attenuates muscle loss during sustained energy deficit induced by calorie restriction and endurance exercise

Park BS, Henning PC, Grant SC, Lee WJ, Lee SR, Arjmandi BH, Kim JS. · Metabolism · 2013

Controlled feeding study showing 3 g/day HMB during a sustained energy deficit attenuated lean mass loss versus control — cited widely in the nutrition literature for HMB's role in muscle preservation during caloric restriction.

PMID: 23876188 · DOI: 10.1016/j.metabol.2013.06.009Read study →

Effect of creatine supplementation during resistance training on lean tissue mass and muscular strength in older adults: a meta-analysis

Chilibeck PD, Kaviani M, Candow DG, Zello GA. · Open Access Journal of Sports Medicine · 2017

Meta-analysis of RCTs showing creatine plus resistance training produced a mean 1.37 kg greater gain in lean tissue mass and superior strength gains versus resistance training alone in older adults.

PMID: 29138605 · DOI: 10.2147/OAJSM.S123529Read study →

International Society of Sports Nutrition position stand: safety and efficacy of creatine supplementation in exercise, sport, and medicine

Kreider RB, Kalman DS, Antonio J, Ziegenfuss TN, Wildman R, Collins R, et al. · Journal of the International Society of Sports Nutrition · 2017

Comprehensive position stand reviewing over 500 studies on creatine, concluding it is the most effective ergogenic nutritional supplement for increasing high-intensity exercise capacity and lean body mass during training.

PMID: 28615996 · DOI: 10.1186/s12970-017-0173-zRead study →

International Society of Sports Nutrition Position Stand: beta-hydroxy-beta-methylbutyrate (HMB)

Wilson JM, Fitschen PJ, Campbell B, Wilson GJ, Zanchi N, Taylor L, et al. · Journal of the International Society of Sports Nutrition · 2013

Position stand reviewing HMB research, concluding that HMB supplementation can enhance recovery and prevent muscle loss during catabolic conditions and caloric restriction.

PMID: 26169411 · DOI: 10.1186/1550-2783-10-6Read study →

SQ[1] Nourish

A daily multivitamin targeting gaps often seen during reduced caloric intake — Vitamin D3, B12, chelated iron, zinc, and magnesium.

Vitamin D Supplementation and Its Impact on Mortality and Cardiovascular Outcomes: Systematic Review and Meta-Analysis of 80 Randomized Clinical Trials

Barbarawi M, Kheiri B, Zayed Y, Gakhal I, Barbarawi O, Bala A, et al. (updated synthesis). · Nutrients · 2023

Meta-analysis of 80 RCTs and 163,131 adults finding vitamin D supplementation was associated with lower all-cause mortality over follow-up of >1 year — supporting vitamin D's role in maintaining healthy status.

PMID: 37111028 · DOI: 10.3390/nu15081810Read study →

The effects of oral ferrous bisglycinate supplementation on hemoglobin and ferritin concentrations in adults and children: a systematic review and meta-analysis of randomized controlled trials

Fischer JAJ, Sasai CS, Karakochuk CD. · Nutrition Reviews · 2023

Meta-analysis of RCTs showing oral ferrous bisglycinate (chelated iron) significantly improved hemoglobin and ferritin concentrations — supporting the use of chelated iron forms for replenishing iron status.

PMID: 35940189 · DOI: 10.1093/nutrit/nuac106Read study →

Zinc supplementation and immune factors in adults: a systematic review and meta-analysis of randomized clinical trials

Mousavi SM, Djafarian K, Mojtahed A, Varkaneh HK, Shab-Bidar S. · Critical Reviews in Food Science and Nutrition · 2022

Meta-analysis of 35 RCTs (n=1,995) finding zinc supplementation significantly reduced CRP and hs-CRP and increased CD4 counts — consistent with zinc's role in supporting normal immune function.

PMID: 33356467 · DOI: 10.1080/10408398.2020.1862048Read study →

Long-term metformin therapy and vitamin B12 deficiency: An association to bear in mind

Infante M, Leoni M, Caprio M, Fabbri A. · World Journal of Diabetes · 2021

Narrative review summarizing evidence that long-term metformin use increases risk of B12 deficiency and supporting routine B12 monitoring and supplementation — relevant to many people on GLP-1 plus metformin regimens.

PMID: 34326945 · DOI: 10.4239/wjd.v12.i7.916Read study →

Vitamin D deficiency and obesity: a systematic review and meta-analysis

Pereira-Santos M, Costa PRF, Assis AMO, Santos CAST, Santos DB. · Obesity Reviews · 2015

Meta-analysis of 23 observational studies (n = 56,239) finding that individuals with obesity had a 35% higher prevalence of vitamin D deficiency compared to normal-weight individuals — supporting routine vitamin D supplementation during weight management.

PMID: 25828941 · DOI: 10.1111/obr.12239Read study →

Clinical Practice Guidelines for the Perioperative Nutrition, Metabolic, and Nonsurgical Support of Patients Undergoing Bariatric Procedures — 2019 Update

Mechanick JI, Apovian C, Brethauer S, Garvey WT, Joffe AM, Kim J, et al. · Endocrine Practice · 2020

Comprehensive clinical guidelines documenting the prevalence and management of nutrient deficiencies (iron, B12, D, calcium, zinc, folate) during medically induced weight loss — the standard reference for nutritional support during bariatric and pharmacological weight management.

PMID: 31893021 · DOI: 10.4158/GL-2019-0375Read study →

SQ[1] Digest

Ginger, a 4-strain probiotic blend, L-glutamine, and prebiotic fiber — formulated to support digestive comfort.

Effects of Ginger Intake on Chemotherapy-Induced Nausea and Vomiting: A Systematic Review of Randomized Clinical Trials

Chang WP, Peng YX. · Nutrients · 2022

Systematic review of 23 RCTs exploring ginger's use as an adjunct to standard antiemetics for nausea and vomiting — the most comprehensive summary of ginger's role in nausea management.

PMID: 36501011 · DOI: 10.3390/nu14234982Read study →

Efficacy of Probiotics in Irritable Bowel Syndrome: Systematic Review and Meta-analysis

Goodoory VC, Khasawneh M, Black CJ, Quigley EMM, Moayyedi P, Ford AC. · Gastroenterology · 2023

Meta-analysis of 82 RCTs (10,332 patients) finding specific probiotic strains and combinations improved global IBS symptoms, abdominal pain, and bloating — supporting targeted probiotic use for digestive comfort.

PMID: 37541528 · DOI: 10.1053/j.gastro.2023.07.018Read study →

Glutamine Supplementation Enhances the Effects of a Low FODMAP Diet in Irritable Bowel Syndrome Management

Rastgoo S, Ebrahimi-Daryani N, Agah S, Karimi S, Taher M, Rashidkhani B, et al. · Frontiers in Nutrition · 2021

6-week RCT: 15 g/day L-glutamine added to a low-FODMAP diet produced a ≥45% IBS-severity improvement in 88% of participants versus 60% with placebo — supporting glutamine's role in gut comfort.

DOI: 10.3389/fnut.2021.746703Read study →

Efficacy of prebiotics, probiotics, and synbiotics in irritable bowel syndrome and chronic idiopathic constipation: systematic review and meta-analysis

Ford AC, Quigley EMM, Lacy BE, Lembo AJ, Saito YA, Schiller LR, et al. · American Journal of Gastroenterology · 2014

Meta-analysis of 43 RCTs finding that probiotics as a group significantly improved global IBS symptoms (RR 0.79) and reduced bloating and flatulence — a foundational reference for probiotic use in GI comfort.

PMID: 24631112 · DOI: 10.1038/ajg.2014.202Read study →

SQ[1] Restore

Marine collagen peptides, hyaluronic acid, and astaxanthin — studied for their role in supporting skin elasticity and hydration.

Effects of Oral Collagen for Skin Anti-Aging: A Systematic Review and Meta-Analysis

de Miranda RB, Weimer P, Rossi RC. · Nutrients / International Journal of Dermatology · 2023

Meta-analysis of 26 RCTs (1,721 participants) showing hydrolyzed collagen supplementation significantly improved skin hydration and elasticity versus placebo after ≥8 weeks of use.

PMID: 37432180 · DOI: 10.1111/ijd.16458Read study →

Oral Supplementation of Collagen Peptides Improves Skin Hydration by Increasing the Natural Moisturizing Factor Content in the Stratum Corneum

Maia Campos PMBG, Franco RSB, Kakuda L, Cadioli GF, Costa GMD, Bouvret E. · Molecules · 2021

12-week randomized, double-blind, placebo-controlled trial in women aged 35–50 showing that oral collagen peptides increased stratum corneum water content and reduced transepidermal water loss.

PMID: 33774639 · DOI: 10.3390/molecules26061602Read study →

Dietary Supplements for Improving Body Composition and Reducing Body Weight: Where Is the Evidence?

Bolke L, Schlippe G, Gerß J, Voss W. · International Journal of Dermatology · 2019

Double-blind, placebo-controlled trial demonstrating that oral collagen peptide supplementation for 12 weeks significantly improved skin elasticity, density, and hydration — one of the earliest rigorous RCTs on collagen for skin health.

PMID: 30681787 · DOI: 10.3390/nu11051249Read study →

Systematic Review and Meta-Analysis on the Effects of Astaxanthin on Human Skin Ageing

Zhou X, Cao Q, Orfila C, Zhao J, Zhang L. · Nutrients · 2021

Meta-analysis of 8 RCTs finding oral astaxanthin significantly improved skin elasticity and moisture content versus placebo — supporting astaxanthin's use for skin health.

PMID: 34578794 · DOI: 10.3390/nu13092917Read study →

SQ[1] Hydrate

Sodium, potassium, and magnesium — essential electrolytes to help maintain fluid balance during reduced caloric intake.

Oral magnesium supplementation for insomnia in older adults: a Systematic Review & Meta-Analysis

Mah J, Pitre T. · BMC Complementary Medicine and Therapies · 2021

Meta-analysis of 3 RCTs (n=151) showing oral magnesium supplementation was associated with a 17-minute reduction in sleep onset latency — supporting magnesium's role in sleep and neuromuscular function.

PMID: 33865376 · DOI: 10.1186/s12906-021-03297-zRead study →

Magnesium for skeletal muscle cramps (Cochrane Systematic Review)

Garrison SR, Korownyk CS, Kolber MR, Allan GM, Musini VM, Sekhon RK, Dugré N. · Cochrane Database of Systematic Reviews · 2020

Cochrane review of 11 RCTs (735 participants) examining magnesium supplementation and skeletal muscle cramps — included for transparency: the evidence for cramp prophylaxis in older adults was limited, while evidence for pregnancy-associated cramps is mixed.

DOI: 10.1002/14651858.CD009402.pub3Read study →

Hydration, sweat and thermoregulatory responses to bike exercise in the heat after electrolyte ingestion

Shirreffs SM, Sawka MN. · Medicine and Science in Sports and Exercise · 2007

Study demonstrating that beverages containing sodium and potassium enhanced fluid retention and restored plasma volume more effectively than plain water — supporting the role of electrolytes in maintaining hydration.

PMID: 17921399 · DOI: 10.1249/mss.0b013e318126ef2bRead study →

Omega-3 fatty acids and inflammatory processes: from molecules to man

Calder PC. · Biochemical Society Transactions · 2017

Comprehensive review of the mechanisms by which omega-3 fatty acids (EPA and DHA) resolve inflammation, including production of specialized pro-resolving mediators — supporting omega-3 supplementation for inflammatory balance during weight loss.

PMID: 28900017 · DOI: 10.1042/BST20160474Read study →

*These statements have not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure, or prevent any disease. Individual results may vary. Consult your healthcare provider before starting any new supplement, especially if you are taking prescription medication. Citations are provided for educational purposes and do not imply endorsement of SQ[1] products by the study authors or publishing journals.

Have a question about a citation or want to suggest additional research? Email our team.