Quick Answer:
Yes, most UK adults should supplement magnesium. Around 10-15% of UK adults fall below adequate intake levels. Magnesium bisglycinate is the most effective form: 90% absorption vs 4% for magnesium oxide, gentle on digestion, no laxative effect. Take 200-400mg daily with food.
Do you actually need to supplement magnesium?
For most UK adults, probably yes.
Data from the UK National Diet and Nutrition Survey (NDNS) shows that a substantial number of adults consume less magnesium than the recommended nutrient intake — particularly women aged 19–64 and adults over 65. Around 10-15% of UK adults fall below the Lower Reference Nutrient Intake, meaning their intake is very likely inadequate.
Magnesium drives over 300 enzymatic reactions in the body: energy production, muscle and nerve function, sleep regulation, blood pressure, and blood sugar control.
The signs of running low show up as everyday things people tend to blame on stress: poor sleep, muscle cramps, low energy, low mood, irritability.
But here’s what most people don’t realise: the form matters more than the number on the label.
Most magnesium supplements don’t work
Walk into any health shop and you’ll see dozens of magnesium products. Most of them are citrate or oxide.
Magnesium citrate is chosen because it’s cheap to produce. The problem: it pulls water into the bowel, which means loose stools or digestive discomfort for a lot of people. Studies show it’s essentially a mild laxative.
Magnesium oxide is even cheaper. It also has the worst absorption rate of any supplemental form — as low as 4%. So you’re paying for magnesium that’s mostly leaving your body unabsorbed.
Both are chosen for cost, not for effectiveness.
Comparison: Magnesium Forms by Absorption Rate
| Form | Absorption Rate | Digestive Tolerance | Best For |
|---|---|---|---|
| Magnesium Oxide | ~4% | Poor (laxative effect) | Constipation relief only |
| Magnesium Citrate | 25-30% | Moderate (loose stools common) | Short-term use |
| Magnesium Bisglycinate | Up to 90% | Excellent (no laxative effect) | Daily supplementation |
Magnesium bisglycinate: the form that actually works
Magnesium bisglycinate (also called magnesium glycinate) is chelated — meaning it’s bound to the amino acid glycine. This makes two things happen:
1. It’s gentle on the gut. Unlike citrate, it doesn’t draw water into the bowel. Magnesium glycinate is widely considered one of the gentlest magnesium forms on the digestive system, with a significantly lower risk of laxative effects. No digestive issues.
2. It’s highly absorbable. The chelation allows it to cross the intestinal wall efficiently and actually get into cells where magnesium does its work. Research indicates magnesium glycinate absorption rates can reach 90% bioavailability, significantly higher than the 4% absorption seen with magnesium oxide.
It costs more to produce, which is why most brands don’t use it. But if you’re supplementing magnesium, it’s the only form worth taking consistently.
Ready to get started with a form that works? HPH Magnesium Bisglycinate, third-party tested, no fillers.
Signs you need magnesium supplementation
If you experience any of the following regularly, there’s a good chance you’re running low:
- Poor sleep quality or difficulty staying asleep — magnesium regulates GABA receptors for sleep
- Muscle cramps, twitches, or tension — magnesium controls muscle contraction and relaxation
- Low energy that doesn’t improve with rest — magnesium is required for ATP (cellular energy) production
- Irritability or low mood — magnesium supports neurotransmitter function
- Brain fog or difficulty concentrating — magnesium affects cognitive performance
You deplete magnesium faster if you:
- Train hard or sweat regularly (athletes lose magnesium through sweat)
- Are under chronic stress (stress hormones increase magnesium excretion)
- Drink alcohol regularly (alcohol reduces magnesium absorption)
- Take certain medications — PPIs (proton pump inhibitors) or diuretics
How much magnesium should I take?
The UK Reference Nutrient Intake (RNI) for magnesium is:
- 300mg per day for men
- 270mg per day for women
If you’re not hitting 400mg+ of magnesium daily from food (dark leafy greens, nuts, seeds, whole grains, legumes), supplementing makes sense.
Recommended supplementation dose: 200-400mg of magnesium bisglycinate per day, taken with food. Most people notice improvements in sleep quality within a week or two. For muscle cramps or recovery, the effect is often faster.
Note on timing:
Take magnesium bisglycinate in the evening 1-2 hours before bed if using it for sleep support. For general supplementation, any time with food works — split the dose (morning and evening) if taking 400mg+ daily.
Key takeaways: Magnesium supplementation in the UK
- 10-15% of UK adults fall below adequate magnesium intake according to NDNS data
- Magnesium bisglycinate has up to 90% absorption vs 4% for magnesium oxide
- Bisglycinate is gentle on digestion — no laxative effect unlike citrate or oxide
- Recommended dose: 200-400mg daily with food
- Benefits appear within 1-2 weeks for most people (sleep, muscle function)
- Look for third-party tested products (Informed Sport certification)
If you’re ready to get started with a form that actually works, we use magnesium bisglycinate in our Magnesium Bisglycinate product — Informed Sport certified, third-party tested, no fillers.
If you’ve read this far, you’re serious about getting this right.
Use code MAGREAD for 15% off Magnesium Bisglycinate — valid for 7 days from today
Frequently Asked Questions
What is the best form of magnesium to take in the UK?
Magnesium bisglycinate is the best form for daily supplementation. It has the highest absorption rate (up to 90%), is gentle on the digestive system, and doesn’t cause laxative effects. Avoid magnesium oxide (only 4% absorption) and citrate (causes digestive issues).
How long does it take for magnesium bisglycinate to work?
Most people notice improvements in sleep quality within 1-2 weeks of consistent supplementation. Effects on muscle cramps and recovery can appear within 3-7 days. Full tissue saturation takes 4-6 weeks of daily supplementation.
Can I take magnesium bisglycinate every day?
Yes. Magnesium bisglycinate is safe for long-term daily use at doses of 200-400mg. It’s well-tolerated with minimal side effects, unlike other forms. Take it with food for optimal absorption.
What’s the difference between magnesium glycinate and bisglycinate?
Magnesium bisglycinate has two glycine molecules bound to one magnesium ion (1:2 ratio), while glycinate has one (1:1 ratio). Bisglycinate is slightly more stable during digestion but both are highly absorbable and gentle. The terms are often used interchangeably.
Does magnesium bisglycinate cause diarrhea?
No. Unlike magnesium citrate and oxide, magnesium bisglycinate does not have a laxative effect. It’s chelated with glycine, which prevents the osmotic water-drawing effect that causes loose stools with other forms.
Should I take magnesium in the morning or at night?
For sleep support, take magnesium bisglycinate 1-2 hours before bed. For general supplementation, any time with food works. If taking 400mg+ daily, split the dose between morning and evening for better absorption.
What foods interact with magnesium absorption?
High-calcium meals can compete with magnesium for absorption. Space them out by 2-3 hours if possible. Magnesium bisglycinate is less affected by this interaction than other forms due to its chelated structure.
Are most people in the UK deficient in magnesium?
According to UK National Diet and Nutrition Survey data, 10-15% of UK adults fall below the Lower Reference Nutrient Intake (deficiency threshold). Many more consume less than the recommended 300mg (men) or 270mg (women) daily, putting them at risk of insufficiency.
Got a question? Reply to the email that was sent to you here, or contact us at info@humanhubltd.co.uk — we read every message.
Roan Heming
Functional Medicine Practitioner, Sports & Performance Nutritionist (Dip.IOPN), Strength Coach & Founder at Human Performance Hub














