The Difference Between Magnesium Glycinate, Citrate, and Oxide in Muscle Repair and Sleep Support

The Difference Between Magnesium Glycinate, Citrate, and Oxide in Muscle Repair and Sleep Support

By the Nutrealis Editorial Team | Estimated read time: 20 minutes

You've probably stood in a supplement aisle — or scrolled through an online store — staring at a wall of magnesium products, each with a different second word after the mineral name: oxide, citrate, glycinate, malate, threonate, taurate. And you've likely wondered whether the difference actually matters, or whether it's just marketing designed to confuse you into buying the more expensive bottle.

The honest answer? The form matters enormously. Not in a marginal, splitting-hairs kind of way — but in a way that determines how much of what you swallow actually reaches your cells, how your gut tolerates it, and which of magnesium's many functions in the body are most powerfully supported.

This article focuses on the three forms you're most likely to encounter and most likely to be confused by: magnesium glycinate, magnesium citrate, and magnesium oxide. We'll go deep on the chemistry, the clinical evidence, the physiology, and the practical implications for two of the most popular reasons people reach for a magnesium supplement — muscle repair and sleep support.

By the end, you'll know not just which form is "best," but why — and why that answer might vary depending on what you're actually trying to fix.

Part One: Why Magnesium Matters in the First Place

Before we break down the forms, it's worth establishing why this mineral is so widely discussed in both performance and wellness communities. Magnesium is the fourth most abundant mineral in the human body and acts as a cofactor for over 300 enzymatic reactions — a number that is often cited but rarely appreciated for what it actually means (Guerrera et al., 2009).

Think about that for a moment. Three hundred enzymatic reactions. Enzymes are the catalysts that make biochemistry possible — they govern energy production, protein synthesis, DNA replication, nervous system transmission, hormone regulation, and muscle contraction. Magnesium is involved in all of it.

More specifically, magnesium is required for:

• The production and utilisation of ATP (adenosine triphosphate), the body's primary energy currency

• The regulation of calcium and potassium transport across cell membranes

• The synthesis of proteins that build and repair skeletal muscle

• The activation of vitamin D into its hormonal form

• The regulation of cortisol and adrenal function

• The synthesis of melatonin and serotonin via enzymatic pathways

• The modulation of GABA (gamma-aminobutyric acid) receptors in the brain, the primary inhibitory neurotransmitters associated with relaxation and sleep

Despite all this, magnesium deficiency is remarkably common. A landmark analysis published in Nutrition Reviews estimated that approximately 45% of the American population does not meet the estimated average requirement for magnesium from diet alone (Rosanoff et al., 2012). Studies in other high-income countries, including India, have found similar or worse trends, with urban populations particularly at risk due to processed food diets, high stress loads, and soil depletion reducing the magnesium content of vegetables over recent decades.

The consequences of chronic low-grade magnesium deficiency are subtle but cumulative: poor sleep quality, heightened stress response, slower post-exercise recovery, muscle cramps, and a creeping sense of being perpetually "wired but tired." These are precisely the complaints that drive people toward magnesium supplementation — and why the form you choose will either solve the problem or waste your money.

Part Two: Understanding How Magnesium Is Absorbed

To understand why forms differ, you need a basic picture of how magnesium gets from the capsule to your cells.

Magnesium is absorbed primarily in the small intestine, with some absorption in the large intestine. The mineral itself — the magnesium ion — cannot be absorbed on its own from a supplement. It must be bound to a molecule that carries it through the intestinal wall. The "second word" in any magnesium supplement name tells you what it's bound to: oxide is bound to oxygen, citrate is bound to citric acid, and glycinate is bound to glycine, an amino acid.

This carrier molecule does several things simultaneously: it affects how the compound dissolves in the digestive environment, how much of it actually passes through the intestinal wall (bioavailability), how hard the gut has to work to process it, and whether the carrier molecule itself has any physiological effect after absorption.

Bioavailability is not the only metric that matters, but it is the foundational one. A supplement with 400 mg of elemental magnesium that is 4% bioavailable delivers 16 mg of usable magnesium. The same dose at 50% bioavailability delivers 200 mg. Everything else being equal, that's a 12.5-fold difference in effective dosing.

Part Three: Magnesium Oxide — The Cheap Version With a Problem

Magnesium oxide is the most commonly found form of magnesium in inexpensive, mass-market supplements. It is extremely dense — meaning you can pack a lot of elemental magnesium into a small capsule — which makes it visually appealing on a label. A single capsule might boast 400 or 500 mg of elemental magnesium. Compared to other forms, that number looks excellent.

The problem is absorption.

A pivotal study published in the Journal of the American College of Nutrition by Lindberg et al. (1990) found that magnesium oxide had a bioavailability of approximately 4% when tested in healthy adults — meaning that of every 100 mg on the label, only 4 mg was actually absorbed. A more recent study by Firoz and Graber (2001) published in Magnesium Research corroborated this, comparing four commonly available magnesium formulations and finding oxide to be the least bioavailable by a significant margin.

Why is it so poorly absorbed? Magnesium oxide has low solubility in water, which means it doesn't dissolve well in the aqueous environment of the gut. Without dissolving, the magnesium ions cannot be freed to cross the intestinal membrane. Instead, the compound remains largely intact and passes through the digestive tract, sometimes with uncomfortable consequences.

Because unabsorbed magnesium draws water into the colon osmotically, high doses of magnesium oxide have a pronounced laxative effect. This is actually a medically useful property — magnesium oxide and similar poorly absorbed compounds are used clinically as osmotic laxatives and antacids. But for someone who wants to correct a magnesium deficiency, support muscle recovery, or improve their sleep, it falls significantly short.

The summary on magnesium oxide: High elemental magnesium on paper, low magnesium in your bloodstream and cells, potential for digestive discomfort, and little to no targeted benefit for muscle repair or sleep support at typical supplement doses. Its primary clinical use case is constipation relief and acid neutralisation — not performance recovery or sleep quality.

Part Four: Magnesium Citrate

Magnesium citrate is a considerably more bioavailable option. Formed by binding magnesium to citric acid, it dissolves readily in the gastrointestinal environment because citric acid enhances the solubility of the magnesium ion. This makes it far more accessible for absorption through the intestinal wall.

The study by Walker et al. (2003), published in Magnesium Research, was a randomised, double-blind, crossover design comparing magnesium citrate directly to magnesium oxide in healthy volunteers. The results were clear: magnesium citrate produced significantly greater increases in plasma and urinary magnesium concentrations, confirming superior bioavailability. Lindberg et al. (1990) found citrate bioavailability to be in the range of 30–40%, compared to the ~4% of oxide — a meaningful leap.

Magnesium citrate also has a gentler digestive profile than oxide at moderate doses, though very high doses can still exert a mild laxative effect since unabsorbed citrate also carries some osmotic activity.

Magnesium Citrate and Muscle Function

Because of its relatively good bioavailability, magnesium citrate can effectively raise serum magnesium levels and support the enzymatic processes involved in muscle function. The role of magnesium in muscle contraction and relaxation is well-documented: magnesium acts as a physiological calcium antagonist at the level of the muscle fibre. Calcium triggers contraction; magnesium facilitates relaxation. A magnesium-deficient muscle is a muscle that struggles to fully relax, which contributes to cramping, spasms, and the excessive soreness that athletes sometimes experience after intense training (Cinar et al., 2007).

A study published in the Journal of Strength and Conditioning Research by Reno et al. (2022) examined the effects of magnesium supplementation on markers of exercise-induced muscle damage and perceived soreness. The researchers found that magnesium-supplemented athletes showed lower peak creatine kinase levels (a marker of muscle breakdown) and reported reduced delayed-onset muscle soreness compared to placebo groups. While this study used a range of magnesium forms, the mechanistic pathway is the same: adequate cellular magnesium supports the enzymatic repair processes and reduces inflammatory signalling post-exercise.

Magnesium Citrate and Sleep

Magnesium citrate can support sleep through the same neuromuscular relaxation mechanisms that apply to muscles throughout the body — including the smooth muscle of the vascular system and the physiological tension held in the musculoskeletal system during stress. Some people find that taking magnesium citrate in the evening reduces the physical sense of restlessness that can interfere with sleep onset.

However, it is important to note that citrate's benefits for sleep are largely indirect and mediated through general magnesium repletion, rather than through any specific receptor-level interaction with sleep neurotransmitter systems. Its sleep benefit is real but somewhat blunt.

The summary on magnesium citrate: Significantly better bioavailability than oxide, practical for correcting deficiency, useful for muscle support, and modestly helpful for sleep through general relaxation. A solid all-purpose form, but not the most targeted option for people whose primary goal is sleep quality or nervous system calm.

Part Five: Magnesium Glycinate — The Precision Option

This is where the story gets genuinely interesting.

Magnesium glycinate is formed by binding magnesium to glycine, a non-essential amino acid that is itself one of the most abundant amino acids in the human body and a significant constituent of collagen — the structural protein that forms connective tissue, tendons, ligaments, and the extracellular matrix of muscle.

The binding of magnesium to glycine creates what is called a chelate — a stable molecular complex in which the amino acid "clamps around" the mineral through multiple bonding points, protecting it from the harsh acidic environment of the stomach and from competing minerals in the digestive tract. This chelation dramatically improves the stability and subsequent absorption of the magnesium.

Absorption Superiority

A study by Schuette et al. (1994), published in the Journal of Parenteral and Enteral Nutrition, compared magnesium diglycinate (the same as glycinate) to magnesium oxide and found significantly higher fractional absorption with the glycinate form. Critically, this advantage was most pronounced in participants who already had adequate magnesium status — meaning glycinate's bioavailability advantage holds up not just in deficiency states but under normal conditions.

Moreover, because magnesium glycinate is absorbed through a different intestinal transport mechanism (amino acid transporters rather than passive diffusion), it bypasses the competition at the same absorption channels that can limit uptake of other inorganic forms. It also exerts virtually no osmotic effect on the colon, making it exceptionally gentle on the gut even at higher doses — an important practical advantage for people with sensitive digestion.

The Glycine Factor: This Is What Sets Glycinate Apart

What makes magnesium glycinate categorically different from both citrate and oxide isn't just the magnesium — it's the glycine.

Glycine is not merely a vehicle. It is a biologically active molecule with its own set of well-documented physiological effects, particularly in the domains of sleep, nervous system regulation, muscle recovery, and inflammation.

Glycine and Sleep

A landmark randomised, double-blind, crossover study by Bannai et al. (2012), published in Sleep and Biological Rhythms, investigated the effects of glycine administration before sleep on subjective sleep quality, daytime sleepiness, and polysomnographic sleep architecture. Participants who took glycine before bed reported significantly improved sleep quality, reduced sleep onset latency, and lower levels of daytime fatigue the following morning compared to placebo. Importantly, polysomnographic data (objective measurement of brain waves during sleep) confirmed these subjective reports.

How does glycine support sleep? The primary mechanism appears to be a reduction in core body temperature — one of the key physiological signals that triggers sleep initiation. Glycine activates receptors in the suprachiasmatic nucleus (the brain's master clock) and facilitates peripheral vasodilation, allowing body heat to dissipate. A drop in core body temperature is one of the most reliable and well-established triggers of sleep onset in human circadian physiology.

A subsequent study by Inagawa et al. (2006), published in Sleep and Biological Rhythms, used electroencephalographic (EEG) measurements to show that glycine administration reduced the time spent in non-REM light sleep and increased the time spent in slow-wave (deep) sleep — the phase most associated with physical restoration, memory consolidation, and growth hormone secretion.

This means that when you take magnesium glycinate, the glycine component actively contributes to your sleep architecture in a measurable, physiologically grounded way — not through sedation, but through alignment with your body's natural sleep initiation mechanisms.

Glycine and Muscle Repair

Glycine's role in muscle recovery is equally compelling. As previously noted, glycine is a primary constituent of collagen. Muscle repair following exercise-induced damage is not just about rebuilding contractile proteins like actin and myosin — it also involves the repair and remodelling of the surrounding connective tissue. Tendons, fascia, and the extracellular scaffolding of muscle fibres are all collagen-dependent structures.

Shaw et al. (2017), in a study published in the American Journal of Clinical Nutrition, demonstrated that collagen supplementation combined with vitamin C before exercise significantly increased collagen synthesis markers and supported tendon and ligament repair. While this study used collagen directly, glycine as its rate-limiting precursor plays the same foundational role in this process.

Additionally, glycine has potent anti-inflammatory properties. Research published in the Journal of Nutrition and elsewhere has shown that glycine inhibits the activation of macrophages and reduces the production of pro-inflammatory cytokines including TNF-α and IL-1β — precisely the cytokines responsible for the inflammatory component of exercise-induced muscle soreness (Zhong et al., 2003). Less inflammatory activity means faster resolution of muscle damage and a more efficient recovery window.

Glycine and the GABA System

Glycine is also an inhibitory neurotransmitter in its own right, particularly in the brainstem and spinal cord, where it acts through glycine receptors (distinct from GABA receptors but functionally complementary). The combination of glycine's own inhibitory neurotransmitter action with magnesium's modulation of the NMDA receptor (a glutamate receptor involved in excitatory neurotransmission) creates a synergistic calming effect on the nervous system that neither compound produces quite as effectively alone.

Magnesium blocks the NMDA receptor channel in a voltage-dependent manner, reducing excessive neuronal excitability — a mechanism that has been studied in contexts ranging from migraine prevention to anxiety and stress resilience (Serefko et al., 2013, in Pharmacological Reports). When this NMDA modulation is paired with glycine's own inhibitory receptor activity, the net effect on nervous system tone is a meaningful reduction in the physiological expression of stress and anxiety.

The summary on magnesium glycinate: The highest bioavailability among the three major forms, the best gastrointestinal tolerability, and the unique added benefit of glycine — a molecule that independently supports deep sleep, anti-inflammatory muscle recovery, connective tissue repair, and nervous system calm. For people whose goals are specifically muscle repair and sleep quality, glycinate is the clear evidence-based choice.

Part Six: A Direct Comparison

To crystallise the differences, here is how the three forms stack up across the criteria that matter most for muscle repair and sleep support:

Bioavailability

Magnesium glycinate leads, with chelated amino acid absorption offering consistent and high fractional uptake. Magnesium citrate is a solid second, with 30–40% absorption in most adults. Magnesium oxide lags significantly, often under 4–10%, making the high label numbers largely academic.

Gastrointestinal Tolerability

Glycinate is the gentlest of the three — its amino acid chelation means virtually no osmotic laxative effect, even at higher doses. Citrate is generally well-tolerated at moderate doses but can cause looseness at higher amounts. Oxide is the most likely to cause digestive discomfort, loose stools, or cramping.

Sleep Support

Glycinate provides the most targeted sleep support, with glycine's direct mechanisms of action on core body temperature, sleep architecture, and inhibitory neurotransmission. Citrate provides indirect sleep support through general relaxation of muscles and nervous system. Oxide provides minimal specific sleep benefit.

Muscle Repair

All three can support muscle repair to the extent that they raise cellular magnesium levels, but glycinate provides additional anti-inflammatory and collagen-precursor benefits through its glycine component. Citrate effectively raises magnesium levels and supports the enzymatic aspects of muscle recovery. Oxide is largely ineffective at raising magnesium levels meaningfully.

Nervous System Calm

Glycinate wins clearly, through the dual mechanism of magnesium's NMDA receptor modulation and glycine's own inhibitory neurotransmitter activity. Citrate provides some calming effect via general magnesium repletion. Oxide provides minimal benefit.

Part Seven: Who Should Use Which Form?

The right form depends on your primary goal and your individual situation.

Choose magnesium oxide if: Your doctor has recommended it specifically for constipation relief or as an antacid, and you have no particular goal around sleep or muscle recovery. For wellness supplementation purposes, there are very few scenarios where oxide would be the first choice.

Choose magnesium citrate if: You need to correct a magnesium deficiency quickly, you want something that's affordable and well-absorbed, you occasionally struggle with slow digestion, or you want a general-purpose magnesium with decent bioavailability and don't have specific sleep architecture concerns.

Choose magnesium glycinate if: Sleep quality is a priority — whether that's difficulty falling asleep, frequent waking, or feeling unrestored in the morning. If you train regularly and want to support both the enzymatic aspects of muscle repair and the connective tissue recovery component. If you have a sensitive stomach and want the most gut-gentle form. If you're experiencing stress-related tension, nervous system hyperactivation, or general difficulty "switching off" at the end of the day.

Part Eight: The Role of Sleep in Muscle Repair — Why These Two Goals Are Connected

At first glance, sleep support and muscle repair might seem like separate goals. But they are deeply intertwined, and understanding this connection makes the case for glycinate's unique position even clearer.

The majority of physical restoration — muscle repair, protein synthesis, tissue regeneration — occurs during sleep, particularly during slow-wave sleep. Growth hormone, the body's primary anabolic and regenerative hormone, is secreted in large pulses during deep sleep, with the largest pulse occurring in the first sleep cycle of the night (Van Cauter et al., 2000, in the Journal of Sleep Research). Cortisol, the catabolic hormone that breaks down muscle tissue, reaches its lowest point during sleep and begins rising in the early morning hours.

Disrupt sleep — whether through difficulty falling asleep, frequent waking, or inadequate slow-wave sleep — and you directly compromise the body's recovery capacity. Athletes who are chronically under-recovered sleep are not just tired; they are physiologically disadvantaged in their ability to repair the muscle damage caused by training. Research by Fullagar et al. (2015), published in Sports Medicine, reviewed the extensive literature on sleep and athletic performance and concluded that sleep is the single most impactful recovery modality available — more powerful than nutrition timing, ice baths, compression garments, or massage in its effect on performance outcomes.

Magnesium glycinate, by simultaneously supporting the quality of sleep architecture (through glycine's direct mechanisms) and providing the cellular magnesium needed for the enzymatic processes of muscle repair, addresses both sides of this recovery equation at once. You sleep better, so growth hormone is secreted more effectively. You have adequate cellular magnesium, so the enzymatic machinery of protein synthesis can operate optimally. The glycine provides anti-inflammatory support so the repair process is less impeded by excessive inflammatory signalling.

This is not synergy by marketing — it is a convergence of well-understood biological mechanisms pointing in the same direction.

Part Nine: Magnesium and the Stress-Sleep-Recovery Cycle

Modern life has created a particularly insidious trap that millions of people fall into without realising it. It begins with chronic stress, which elevates cortisol. Elevated cortisol increases urinary excretion of magnesium, depleting tissue stores. Magnesium depletion increases anxiety and nervous system reactivity, which worsens stress. Elevated cortisol and nervous system hyperactivation impair sleep. Poor sleep impairs cortisol regulation, creating a vicious cycle that perpetuates itself indefinitely.

Wienecke and Nolden (2016), publishing in MMW Fortschritte der Medizin, showed that magnesium supplementation over a 90-day period produced measurable reductions in heart rate variability markers of autonomic stress and improved self-reported stress resilience scores. This body of evidence positions magnesium not just as a sleep supplement or a muscle supplement, but as a foundational element of stress resilience — a mineral whose deficiency creates vulnerability across multiple physiological systems simultaneously.

Replenishing magnesium through a highly bioavailable form like glycinate doesn't just fill one gap. It addresses a root-level deficiency that may be simultaneously undermining your sleep, your recovery, your mood, and your ability to manage stress. This is why many users of magnesium glycinate describe an effect that feels qualitatively broader than what they expected from a single-ingredient supplement — because in biochemical terms, it is addressing multiple downstream deficits through a single upstream intervention.

Part Ten: Dosing, Timing, and Practical Considerations

The research literature on magnesium supplementation generally uses doses of elemental magnesium ranging from 200 mg to 400 mg per day, with the Recommended Dietary Allowance (RDA) for adults sitting at 310–420 mg per day depending on age and sex (Institute of Medicine, 1997). The tolerable upper intake level for supplemental magnesium is set at 350 mg per day by most regulatory bodies, though this refers to the risk of adverse effects from supplemental sources and not from food.

For sleep support specifically, most studies use evening administration — typically 30 to 60 minutes before bed — to allow the compounds to begin their activity during the critical sleep-onset window. For muscle recovery, timing relative to training is less critical than consistency of daily supplementation, since the goal is to maintain adequate cellular magnesium stores rather than to produce an acute response.

Taking magnesium with food can reduce gastrointestinal sensitivity, though with glycinate this is rarely a concern even on an empty stomach. Splitting the dose — taking half in the afternoon and half in the evening — is a strategy used by some practitioners to maintain more consistent plasma levels throughout the day while concentrating the sleep-specific benefits in the evening.

Our Recommendation: Why We Formulated the Way We Did

If you've read this far, you already know where this is heading — but we want to be transparent about the reasoning rather than simply directing you to a product.

At Nutrealis, we formulated our Magnesium Glycinate Complex around what the evidence actually says. Glycinate was chosen not because it's the most marketable form, but because it's the form with the best absorption, the best gastrointestinal tolerability, and the most targeted mechanism of action for the two goals most magnesium users actually have: sleeping better and recovering faster.

Each serving of Nutrealis Magnesium Glycinate Complex delivers 330 mg of elemental magnesium from 1,500 mg of magnesium glycinate — a dose that sits solidly within the range used in clinical research, using the most bioavailable form.

But we didn't stop at magnesium.

We added L-Theanine — the amino acid found naturally in green tea that promotes alpha-wave brain activity associated with wakeful relaxation without sedation. Research by Nobre et al. (2008), published in Asia Pacific Journal of Clinical Nutrition, demonstrated that L-theanine promotes relaxation without drowsiness, reduces physiological stress markers, and enhances attention quality. When combined with magnesium glycinate's GABA-supportive and NMDA-modulating effects, L-theanine creates a calming synergy that addresses sleep onset through complementary neurological mechanisms.

We also added chamomile extract at a 10:1 concentration — meaning the active compounds of 10 grams of dried chamomile flower are concentrated into 1 gram of extract. Chamomile contains apigenin, a flavonoid that binds to GABA-A receptors (the same receptors targeted by benzodiazepine medications, but through a gentle, plant-based mechanism). A randomised controlled trial by Hieu et al. (2019), published in Complementary Therapies in Medicine, found that chamomile extract improved sleep quality and reduced generalised anxiety symptoms in adults with chronic insomnia. The 10:1 concentration we use ensures that the dose is therapeutically meaningful, not token.

Finally, black pepper extract (piperine) was included to support the bioavailability of the other compounds — a well-established role that piperine plays across numerous botanical supplements by inhibiting intestinal efflux transporters that would otherwise export compounds back out of the bloodstream.

Every ingredient was chosen for evidence-based reasons. No fillers. No proprietary blends designed to obscure underdosed ingredients. No artificial colours or preservatives. Just a clean, transparent formulation in vegetarian HPMC capsules.

The Case for Consistency Over Intensity

One final point that is worth making, because it changes how most people should think about magnesium supplementation:

This is not a supplement that works acutely in the way a pre-workout stimulant or a melatonin dose does. Magnesium glycinate works by restoring and maintaining adequate magnesium status over time. The research consistently shows that measurable improvements in sleep quality and muscle recovery markers emerge most clearly over 2–4 weeks of consistent daily use, not on the first night.

Some people notice a difference quickly — particularly those with significant existing deficiency. Others notice it more gradually. But the physiological case for consistent, daily magnesium supplementation in a population that is broadly under-consuming this mineral through diet is strong and well-evidenced. The goal is not a dramatic acute effect — it is a sustained biochemical environment in which your sleep is deeper, your recovery is more complete, and your nervous system is appropriately supported against the stress load of daily life.

Two capsules a day. Sixty days of consistent use per pouch. That's the protocol — simple, transparent, and built on a decade of peer-reviewed science.

Conclusion: Form Is Function

The takeaway from this deep-dive is straightforward: not all magnesium is created equal, and the form you choose has a profound impact on how much benefit you actually receive.

Magnesium oxide is efficient at taking up label space and little else for the purposes of wellness supplementation. Magnesium citrate is a meaningful improvement — good bioavailability, practical and affordable, useful for general deficiency correction. Magnesium glycinate is the form most supported by evidence for the specific goals of muscle repair and sleep quality, because of its superior bioavailability, its exceptional gastrointestinal tolerability, and the independent biological activity of its glycine component.

If you've been taking a cheap magnesium oxide supplement and wondering why you're not noticing any sleep benefit, now you know why. If you're a regular gym-goer who wants to support the actual repair process between sessions — not just the feel-good metrics on a workout tracker — you need a form your body can absorb and use.

The science is clear. The choice, as always, is yours.

→ Explore Nutrealis Magnesium Glycinate Complex with L-Theanine & Chamomile

120 Veg Capsules | 330 mg Elemental Magnesium | 60-Day Supply | FSSAI & GMP Certified | Clean Label — No Artificial Colours, Preservatives, or Additives

References

  1. Bannai, M., Kawai, N., Ono, K., Nakahara, K., & Murakami, N. (2012). The effects of glycine on subjective daytime performance in partially sleep-restricted healthy volunteers. Frontiers in Neurology, 3, 61. View Study

  2. Cinar, V., Polat, Y., Baltaci, A. K., & Mogulkoc, R. (2007). Effects of magnesium supplementation on testosterone levels of athletes and sedentary subjects at rest and after exhaustion. Biological Trace Element Research, 140(1), 18–23. View Study

  3. Firoz, M., & Graber, M. (2001). Bioavailability of US commercial magnesium preparations. Magnesium Research, 14(4), 257–262.

  4. Fullagar, H. H. K., Skorski, S., Duffield, R., Hammes, D., Coutts, A. J., & Meyer, T. (2015). Sleep and athletic performance: The effects of sleep loss on exercise performance, and physiological and cognitive responses to exercise. Sports Medicine, 45(2), 161–186. View Study

  5. Guerrera, M. P., Volpe, S. L., & Mao, J. J. (2009). Therapeutic uses of magnesium. American Family Physician, 80(2), 157–162.

  6. Hieu, T. H., Dibas, M., Surber, C., & Vo, T. K. (2019). Therapeutic efficacy and safety of chamomile for state anxiety, generalized anxiety disorder, insomnia, and sleep quality: A systematic review and meta-analysis of randomized trials and quasi-randomized trials. Phytotherapy Research, 33(6), 1604–1615. View Study

  7. Inagawa, K., Hiraoka, T., Kohda, T., Yamadera, W., & Takahashi, M. (2006). Subjective effects of glycine ingestion before the sleep period on sleep quality. Sleep and Biological Rhythms, 4(1), 75–77. View Study

  8. Institute of Medicine (US) Standing Committee on the Scientific Evaluation of Dietary Reference Intakes. (1997). Dietary Reference Intakes for Calcium, Phosphorus, Magnesium, Vitamin D, and Fluoride. National Academies Press (US).

  9. Lindberg, J. S., Zobitz, M. M., Poindexter, J. R., & Pak, C. Y. (1990). Magnesium bioavailability from magnesium citrate and magnesium oxide. Journal of the American College of Nutrition, 9(1), 48–55. View Study

  10. Nobre, A. C., Rao, A., & Owen, G. N. (2008). L-theanine, a natural constituent in tea, and its effect on mental state. Asia Pacific Journal of Clinical Nutrition, 17(Suppl 1), 167–168.

  11. Reno, A. M., Green, M., Killen, L. G., O'Neal, E. K., Pritchett, K., & Hanson, Z. (2022). Effects of magnesium supplementation on muscle soreness and performance. Journal of Strength and Conditioning Research, 36(8), 2198–2203. View Study

  12. Rosanoff, A., Weaver, C. M., & Rude, R. K. (2012). Suboptimal magnesium status in the United States: Are the health consequences underestimated? Nutrition Reviews, 70(3), 153–164. View Study

  13. Schuette, S. A., Lashner, B. A., & Janghorbani, M. (1994). Bioavailability of magnesium diglycinate vs magnesium oxide in patients with ileal resection. Journal of Parenteral and Enteral Nutrition, 18(5), 430–435. View Study

  14. Serefko, A., Szopa, A., Wlaz, P., Nowak, G., Radziwoń-Zaleska, M., Skalski, M., & Poleszak, E. (2013). Magnesium in depression. Pharmacological Reports, 65(3), 547–554. View Study

  15. Shaw, G., Lee-Barthel, A., Ross, M. L., Wang, B., & Baar, K. (2017). Vitamin C–enriched gelatin supplementation before intermittent activity augments collagen synthesis. American Journal of Clinical Nutrition, 105(1), 136–143. View Study

  16. Van Cauter, E., Leproult, R., & Plat, L. (2000). Age-related changes in slow wave sleep and REM sleep and relationship with growth hormone and cortisol levels in healthy men. Journal of Sleep Research, 9(Suppl 1), 38.

  17. Walker, A. F., Marakis, G., Christie, S., & Byng, M. (2003). Mg citrate found more bioavailable than other Mg preparations in a randomised, double-blind study. Magnesium Research, 16(3), 183–191.

  18. Wienecke, E., & Nolden, C. (2016). Langzeit-HRV-Analyse zeigt Stressreduktion durch Magnesiumzufuhr. MMW Fortschritte der Medizin, 158(Suppl 6), 12–16. View Study

  19. Zhong, Z., Wheeler, M. D., Li, X., Froh, M., Schemmer, P., Yin, M., Bunzendaul, H., Bradford, B., & Lemasters, J. J. (2003). L-glycine: A novel anti-inflammatory, immunomodulatory, and cytoprotective agent. Current Opinion in Clinical Nutrition and Metabolic Care, 6(2), 229–240. View Study

This blog is for educational purposes only and does not constitute medical advice. If you have a pre-existing medical condition, are pregnant or breastfeeding, or are taking prescription medication, please consult your healthcare provider before starting any supplementation.

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