Source Naturals Magnesium Glycinate Tabs: Bioavailable Muscle, Nerve, and Sleep Support
Evidence-Based • Fact-Checked Review•Published by VitaNet Health Editorial Team•Updated for Clinical Accuracy
If you have ever taken a magnesium supplement and experienced an upset stomach, you are not alone. Common forms like magnesium oxide draw water directly into the bowel, often causing rapid digestive distress before your cells can absorb the mineral.
Source Naturals Magnesium Glycinate tabs (SKU: SN2132) solve this problem through smart molecular design. By bonding magnesium directly to glycine—a gentle, naturally calming amino acid—this chelated formula bypasses typical digestive bottlenecks. The result is a highly absorbable tablet designed to replenish mineral reserves, relax tight muscle tissue, and help quiet an overactive nervous system before bed.
At a Glance: Why Choose This Formula
✓Gentle on Digestion: Organic bis-glycinate chelate minimizes the loose stool effect common in cheaper forms.
✓200 mg Elemental Magnesium Per Serving: Delivers 48% of your Daily Value in just two easy-to-swallow tablets.
✓Dual-Action Calm: Glycine crosses the blood-brain barrier to encourage neurotransmitter balance alongside muscular relaxation.
✓Clean Formula: Free from gluten, dairy, egg, soy, corn, wheat, artificial colors, and preservatives.
The Science of Chelation: Why Magnesium Bis-Glycinate Absorbs Better
Magnesium is a vital element required for more than 300 biochemical reactions in the human body, ranging from energy production (ATP synthesis) to heart rhythm stability. Yet according to data from the National Health and Nutrition Examination Survey (NHANES), nearly half of all Americans do not consume enough magnesium from their diets alone.
The challenge is not just taking magnesium; it is getting it across your intestinal lining and into your bloodstream.
What Does "Chelated" Actually Mean?
The word comes from the Greek term chele, meaning "claw." In Source Naturals Magnesium Glycinate, a single elemental magnesium ion is held firmly by two molecules of glycine (forming magnesium bis-glycinate). This organic structure creates a neutral electrical charge that shields the mineral from binding with dietary compounds like phytates and oxalates that would otherwise block its absorption.
Because your intestines absorb peptides and amino acids very efficiently using specialized transport channels (PEPT1 pathways), the entire complex is absorbed intact. A landmark clinical trial published in JPEN (Journal of Parenteral and Enteral Nutrition) demonstrated that magnesium diglycinate achieved substantially higher serum absorption levels than inorganic magnesium oxide, particularly in individuals with sensitive digestive tracts.
Evidence-Based Benefits: How Magnesium Glycinate Supports Daily Health
1. Encourages Deep Sleep and Nighttime Recovery
Magnesium acts as a natural regulator of gamma-aminobutyric acid (GABA), the primary neurotransmitter responsible for downshifting brain activity in the evening. In a double-blind, randomized controlled trial published in the Journal of Research in Medical Sciences (Abbasi et al., 2012), 500 mg of daily magnesium supplementation significantly improved sleep efficiency, sleep duration, and early morning awakening scores while lowering serum cortisol concentrations. Pairing magnesium with glycine offers extra support, as glycine itself has been shown to support body temperature regulation during deep REM cycles.
2. Relieves Muscle Twitches, Spasms, and Post-Workout Tightness
Muscle contraction and relaxation depend on a delicate ratio of calcium to magnesium. While calcium tells muscle fibers to contract, magnesium tells them to release. When cellular magnesium levels drop, calcium floods the nerve endings, resulting in nighttime leg cramps, eyelid twitches, and lingering stiffness. Maintaining healthy intracellular magnesium helps reset neuromuscular balance.
3. Helps Manage Everyday Stress and Mental Fatigue
During periods of chronic physical or psychological stress, your kidneys excrete magnesium at an accelerated rate—creating a vicious cycle where stress depletes magnesium, making your central nervous system even more vulnerable to future tension. A comprehensive systematic review published in Nutrients (Boyle et al., 2017) confirmed that regular magnesium intake helps support calm behavioral responses and resilience against subjective anxiety.
4. Cardiovascular and Skeletal Integrity
Over 60% of bodily magnesium resides in bone tissue, where it works alongside vitamin D and calcium to preserve structural density. In the vascular system, magnesium acts as a physiological calcium channel blocker, promoting healthy arterial elasticity and normal blood pressure levels already within the normal range (DiNicolantonio et al., Open Heart, 2018).
Comparing Forms: Magnesium Glycinate vs. Citrate, Oxide, and Malate
With so many magnesium products on the market, matching the chemical form to your specific health objective is essential for getting real results:
Magnesium Form
Absorption Rate
Stomach Comfort
Primary Health Application
Bis-Glycinate (Source Naturals)
Very High
Exceptional (Non-Laxative)
Sleep, muscle cramps, stress resilience, general repletion
Citrate
Moderate to High
Can cause loose stools
Occasional constipation relief
Oxide
Low (~4% bioavailability)
Frequent laxative effect
Antacid, short-term colon cleanse
Malate
High
Gentle
Daytime energy production, muscle soreness
L-Threonate
High (Crosses BBB easily)
Gentle
Focus, memory, and cognitive support
Complete Supplement Facts & Ingredient Breakdown
Transparency is fundamental to our standards. Below is the verified nutrient and excipient profile for Source Naturals Magnesium Glycinate 120 Tablets (SKU: SN2132):
Supplement Facts
Serving Size: 2 Tablets
Servings Per Container: 60
Recommended Dosage, Optimal Timing, and Safe Usage
Standard Serving Directions
Take 2 tablets twice daily with meals or a full glass of water, or as advised by your healthcare professional. This daily protocol provides 400 mg of elemental magnesium (95% Daily Value), comfortably meeting the Recommended Dietary Allowance (RDA) for adult men (400–420 mg) and adult women (310–320 mg).
Best Time of Day to Take It
For sleep and evening relaxation: Take your second 2-tablet serving approximately 30 to 60 minutes before bedtime. For muscle tightness and daytime calm: Split your dose between breakfast and dinner to maintain stable cellular mineral levels throughout the entire day.
Precautions & Drug Interactions
Individuals with severe renal impairment (kidney disease) must not take supplemental magnesium without direct medical supervision, as the kidneys regulate mineral excretion. If you are taking oral antibiotics (such as tetracyclines or fluoroquinolones) or bisphosphonates for bone density, take your magnesium supplement at least 2 to 4 hours apart to prevent binding interactions. Consult your doctor if pregnant or nursing.
Frequently Asked Questions About Magnesium Glycinate
Will Source Naturals Magnesium Glycinate tabs cause diarrhea or loose stools?
Unlike magnesium oxide or unbuffered citrate, magnesium bis-glycinate is bound to the amino acid glycine and is absorbed intact through dipeptide channels. It does not pull excess water into the large intestine, making it the preferred choice for people with sensitive digestive tracts or IBS.
What does "200 mg elemental magnesium" mean on the label?
"Elemental" magnesium refers to the actual weight of the pure mineral itself, excluding the weight of the attached glycine molecules. A serving of 2 tablets gives you a full 200 mg of usable, bioavailable elemental magnesium (48% of your Daily Value).
How long does it take for magnesium glycinate tablets to work?
For acute evening calm and muscle tension relief, many users notice a difference within 45 to 90 minutes. However, restoring depleted cellular mineral stores and experiencing sustained improvements in sleep cycles and chronic muscle cramps typically takes 2 to 4 weeks of consistent daily supplementation.
Can I take magnesium glycinate with my daily multivitamin?
Yes. However, if your multivitamin contains high doses of elemental zinc (above 30 mg) or high elemental calcium (above 500 mg), they may compete for similar absorption pathways. For optimal absorption, take your magnesium glycinate tablets in the evening and your multivitamin with breakfast.
Why is calcium phosphate included in this formula?
Dibasic calcium phosphate is used as a functional tablet binder and mineral carrier. It delivers 140 mg of calcium per serving, supporting the physiological ratio needed for healthy neuromuscular signaling and bone remodeling.
How does SKU SN2132 differ from generic magnesium capsules?
Source Naturals manufactures under strict FDA Good Manufacturing Practices (cGMP) standards with over 40 years of quality verification. SKU SN2132 utilizes fully reacted chelated bis-glycinate pressed into dense tablets, delivering higher mineral density per bottle than bulky powdered capsules that often contain hidden fillers.
Scientific References & Authoritative Citations
Schuette, S. A., Lashner, B. A., & Janghorbani, M. (1994). Bioavailability of a new form of magnesium: Magnesium diglycinate vs. magnesium oxide in patients with ileal resection. JPEN: Journal of Parenteral and Enteral Nutrition, 18(5), 430–435.
Abbasi, B., Kimiagar, M., et al. (2012). The effect of magnesium supplementation on primary insomnia in elderly: A double-blind placebo-controlled clinical trial. Journal of Research in Medical Sciences, 17(12), 1161–1169.
Boyle, N. B., Lawton, C., & Dye, L. (2017). The Effects of Magnesium Supplementation on Subjective Anxiety and Stress—A Systematic Review. Nutrients, 9(5), 429.
DiNicolantonio, J. J., O'Keefe, J. H., & Wilson, D. (2018). Subclinical magnesium deficiency: a principal driver of cardiovascular disease and a public health crisis. Open Heart, 5(2), e000668.
National Institutes of Health (NIH) Office of Dietary Supplements. Magnesium Fact Sheet for Health Professionals. Updated clinical reference guide.
*Disclaimer: 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. Always consult your personal physician before beginning any new nutritional supplement protocol.
