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Magnesium Bisglycinate
Pure magnesium. Precisely formulated.
A daily 200 mg elemental magnesium formula from fully reacted magnesium bisglycinate for everyday relaxation and wellbeing.
The form of magnesium matters.
Magnesium is an essential mineral involved in hundreds of processes throughout the body. But when it comes to supplementation, the amount of magnesium on the label is only part of the story. The form in which it is delivered matters too.
Magnesium bisglycinate is a chelated form of magnesium in which magnesium is bound to two molecules of the amino acid glycine. This creates a stable magnesium–glycine complex and is recognised as a highly bioavailable, well-tolerated form of magnesium for daily supplementation.
Protokols Magnesium Bisglycinate is deliberately different. We use a fully reacted, unbuffered magnesium bisglycinate with no magnesium oxide and no alternative magnesium forms added to inflate the elemental magnesium content. Two capsules provide a meaningful 200 mg of elemental magnesium, entirely from magnesium bisglycinate.
And because purity is one of our principles, we stopped there. No unnecessary excipients. No complicated blends. No hidden magnesium forms. Just magnesium bisglycinate inside a plant-based capsule, produced under controlled manufacturing standards and batch tested for quality.
Magnesium contributes to the reduction of tiredness and fatigue, normal energy-yielding metabolism, normal muscle function, normal functioning of the nervous system and normal psychological function.
Pure in formulation. Proven in purpose. Premium by design.
Nutritional Information
Ingredients: Magnesium (Bisglycinate), Capsule Shell (Hydroxypropyl Methylcellulose)
2 capsules will provide:
| Active Nutrient | Amount per Serving | %NRV* |
|---|---|---|
| Magnesium (as bisglycinate) | 200 mg | 53 |
*NRV = Nutritional Reference Value
The studies below relate to the ingredient or nutrient form. Unless explicitly stated they are not trials of the finished Protokols product and do not guarantee an individual result.
01 — Magnesium Bisglycinate & Sleep
Randomised, double-blind, placebo-controlled trial · 2025
A clinical trial involving 155 adults with self-reported poor sleep investigated 250 mg of elemental magnesium from magnesium bisglycinate daily for four weeks.
Participants receiving magnesium bisglycinate experienced a modest but statistically significant improvement in insomnia severity compared with placebo. The supplement was also reported to be well tolerated.
02 — Magnesium Bisglycinate, Absorption & Tolerability
Double-blind, randomised crossover trial · 1994
Researchers compared magnesium diglycinate — another name for magnesium bisglycinate — with magnesium oxide.
While overall absorption was comparable across the complete study population, the chelated form showed significantly greater absorption among participants who absorbed magnesium oxide least effectively. Magnesium diglycinate was also better tolerated in the study population.
03 — Magnesium Form & Bioavailability
Systematic review · 2021
A systematic review examined 14 human studies comparing the bioavailability of different forms of supplemental magnesium.
The researchers concluded that inorganic magnesium formulations generally appeared to be less bioavailable than organic formulations, while also recognising that absorption is influenced by factors including dosage and individual magnesium status.
04 — Magnesium, Sleep & Anxiety
Systematic review · 2024
This review examined 15 interventional studies investigating magnesium supplementation in relation to sleep and anxiety.
Five of eight studies assessing sleep reported improvements in at least one sleep measure, while five of seven studies assessing anxiety reported improvements. The researchers described the overall evidence as encouraging while highlighting differences in study size, formulation and dosage.
05 — Magnesium & Sleep Onset
Systematic review & meta-analysis · 2021
Researchers analysed randomised controlled trials investigating magnesium supplementation in older adults experiencing insomnia.
Across three trials involving 151 participants, magnesium supplementation was associated with participants falling asleep approximately 17 minutes sooner than placebo. The authors noted that the available evidence was limited in quality and that further high-quality trials are needed.
06 — Why Magnesium Matters
Scientific review · 2024
Magnesium is much more than a single-purpose mineral.
A comprehensive scientific review describes magnesium as a cofactor in more than 300 enzymatic reactions, with important roles in energy metabolism, ATP utilisation, protein synthesis, nerve transmission and normal muscle function.
07 — Understanding the Magnesium–Glycine Chelate
Scientific review of magnesium coordination chemistry · 2020
Research into the chemistry of magnesium complexes describes how magnesium and glycine can form a magnesium bisglycinate complex at a 1:2 magnesium-to-glycine ratio, with the glycine molecules coordinating with the magnesium ion.
The review also discusses the greater solubility observed with organic magnesium complexes compared with magnesium oxide and the scientific rationale behind amino-acid-chelated magnesium forms.
Dosage Take 2 capsules daily.
Serving 2 capsules provide 200 mg elemental magnesium.
Directions Take with food and water, or as directed by a healthcare professional.
Suitability Suitable for vegetarians and vegans.
Free UK Delivery
Enjoy free standard UK delivery on every order.
14-Day First-Purchase Returns
Trying Magnesium Bisglycinate for the first time? You can request a return within 14 days of delivery, provided the product remains unopened, unused and in its original sealed packaging.
For return instructions, damaged orders and your statutory rights, please see our Returns & Refunds Policy.
Storage
Store in the original container in a cool, dry place, away from heat, moisture and direct sunlight. Keep tightly closed and do not refrigerate.
Best before end and batch number: See base of tub.
Keep out of the sight and reach of young children.
Safety
Do not exceed the recommended daily dose of 2 capsules (200 mg elemental magnesium). Food supplements should not be used as a substitute for a varied, balanced diet and healthy lifestyle.
Consult your doctor or pharmacist before use if you are pregnant, breastfeeding, taking medication or have a medical condition, particularly impaired kidney function.
Magnesium can affect the absorption of certain medicines, including some antibiotics and bisphosphonates. Ask your doctor or pharmacist about appropriate timing if you take regular medication.
If you use other magnesium supplements, check your total daily intake before combining products.
Discontinue use and seek medical advice if you experience an adverse reaction. Do not use if the safety seal is broken or missing.
PURE | PROVEN | PREMIUM
Realistic Expectations
If you are going to judge this product, judge it at twelve weeks, not at two.
Day 1
Weeks 1–4
Weeks 8–12
Ongoing
How we compare?
Which Protokols include this?
Restore Protokol
An evening routine designed to support calm, wind-down and better-quality rest.
Renew Protokol
With Magnesium Bisglycinate. Skin first — collagen in the morning, a calmer evening to let your body use it.
Frequently Asked Questions (FAQs)
Magnesium bisglycinate is a chelated form of magnesium, where one magnesium ion is associated with two molecules of the amino acid glycine.
This creates the magnesium–glycine complex known as magnesium bisglycinate, a form commonly chosen for its bioavailability and good digestive tolerance.
Yes. Magnesium glycinate, magnesium bisglycinate and magnesium diglycinate are names used for the same magnesium–glycine compound.
The word “bis” simply makes the chemistry more explicit: there are two glycine molecules associated with the magnesium ion.
Because the form of magnesium matters, not just the number printed on the bottle.
Research comparing magnesium formulations suggests that organic magnesium forms can offer good bioavailability, while magnesium diglycinate has also demonstrated good tolerability in human research. We wanted a clean, single-form magnesium rather than a multi-magnesium blend.
Two capsules provide 200 mg of elemental magnesium, with 100 mg per capsule.
Elemental magnesium is the actual amount of magnesium supplied by the magnesium compound.
Magnesium bisglycinate also contains glycine, so the total weight of the compound will always be much higher than the amount of magnesium itself. When comparing supplements, look for the elemental magnesium per daily serving, not simply the largest milligram number on the bottle.
In a fully reacted magnesium bisglycinate, the magnesium and glycine have been reacted to create the intended magnesium–glycine chelate, rather than simply being mixed together as separate ingredients.
For Protokols, we specifically chose a fully reacted bisglycinate because we wanted the magnesium form stated on the bottle to be the form inside the capsule.
No unnecessary excipients.
The finished-product specification lists magnesium bisglycinate with no excipients, enclosed in a plant-based HPMC capsule shell.
No bulking agents. No flow agents. No complicated active blend.
It depends on how you want it to fit into your routine.
During the day: take it when you want magnesium to form part of your everyday calm and wellbeing routine.
For your evening routine: take your daily serving approximately 30–60 minutes before bed.
Interestingly, a 2025 randomised controlled trial specifically investigating magnesium bisglycinate instructed participants to take their dose 30–60 minutes before bedtime.
Yes. Your daily serving is two capsules in total.
You can take both together, or take one earlier in the day and one later, depending on what works best with your routine.
Do not exceed the recommended daily dose unless advised by a healthcare professional.
It isn't a sedative or sleeping tablet.
Magnesium bisglycinate can therefore be taken during the day as well as in the evening. We particularly like it as part of a wind-down routine, rather than positioning it as something designed to “knock you out”.
Calm, not sedation.
There is no universal timeline.
In the 2025 magnesium-bisglycinate sleep trial, most of the improvement occurred during the first two weeks, with supplementation continuing for four weeks. Individual responses varied, and people with lower dietary magnesium intake appeared to respond more strongly in exploratory analysis.
Our approach is simple: take it consistently and judge the outcome over time, not after one capsule.
Magnesium bisglycinate is commonly selected when digestive tolerance matters.
In a randomised crossover study comparing magnesium diglycinate with magnesium oxide in people with impaired intestinal absorption, the chelated form was better tolerated by all participants. The study population was specific, so this should not be interpreted as a guarantee that everyone will respond in the same way.
If you have a sensitive stomach, taking your capsules with food can also help.
For most people, magnesium can form part of a wider supplement routine. However, check how much magnesium you are already receiving from other supplements so you are not unintentionally doubling your intake.
If you take prescription medicines, it is worth checking with your doctor or pharmacist. Magnesium can interfere with the absorption of certain medicines, particularly some antibiotics and oral bisphosphonates, when taken too closely together.
Speak to a healthcare professional before use if you are pregnant, breastfeeding, taking regular medication, have a medical condition or have impaired kidney function.
Kidneys play an important role in regulating magnesium, making additional caution appropriate where renal function is significantly impaired.
Yes — it has been formulated as a daily supplement.
Take two capsules daily, providing 200 mg elemental magnesium. One tub contains 60 capsules, providing a 30-day supply.
Consistency matters more than occasionally taking a larger dose.
Yes. Every Protokols batch is independently tested for identity, purity and potency before we put our name behind it.
For us, Proven means verifying what's inside — not simply trusting what was supposed to go in.
Thoughtfully formulated supplements. Clear ingredients, considered routines, and wellbeing made simpler.