High Potency Magnesium 300mg 120 Capsules
by Viridian
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Viridian High Potency Magnesium 300mg combines three magnesium forms — citrate, oxide, and bisglycinate — in a clean-label capsule from a well-regarded UK brand. Best for People struggling with poor sleep or night-time muscle cramps and Those seeking a clean-label supplement with no artificial additives.
According to the AIScored 0–100 scoring system, High Potency Magnesium 300mg 120 Capsules by Viridian scores 71.0/100, ranking #12 out of 19 products in Magnesium (2026). Strongest category: Side Effects (84.0/100). Weakest: Certifications (57.0/100).
Is High Potency Magnesium 300mg 120... worth buying?
“Viridian's High Potency Magnesium 300mg combines three magnesium forms for better absorption, and reviewers frequently report improved sleep within weeks. At 71/100, it's a clean, filler-free UK formula that prioritises ingredient quality over hype.”
What Do Reviewers Say About High Potency Magnesium 300mg 120 Capsules?
Sample excerpts from currently available source material used in this product analysis.
"This magnesium formula is miraculous. It is a game changer. I feel more energised but relaxed at the same time. My sleep is also greatly, improved. The puffiness in my ankles has reduced and almost gone. I will definitely be buying this pro..."
"antes tomaba un, Magnesio, y ahora he cambiado a este que son tres tipos en uno, de momento no he notado ninguna diferencia, quizá podría reseñar que quizá duermo un poco mejor, pero nada más"
"My doctors advised me to take these tablets to help with my sleep. I've had several jars and I'm very happy with them and my sleep has improved. It's a comfortable dosage with no obvious side-affects."
"I’ve been using Viridian’s High Potency Magnesium for a few weeks now, and overall, I’ve found it to be a solid supplement. I decided to try it out mostly to help with tiredness and fatigue, and I've noticed some improvement in my energy le..."
"Easier to swallow than the tablets, no acid burn , generally felt better after taking for a couple of weeks or so 😀"
How does High Potency Magnesium 300mg 120 Capsules score?
Detailed score breakdown and key findings from our analysis of 11 reviews across 1 source.
Pros
- +Strong sleep improvement reported by multiple independent reviewers
- +Clean formula with no artificial fillers or additives — consistent with Viridian's brand standard
- +Triple magnesium blend (citrate + bisglycinate + oxide) improves coverage across absorption pathways
- +Easy-to-swallow capsules with no aftertaste reported
- +Reputable UK brand with in-house nutritionist support and 130 quality checks
Cons
- -Magnesium oxide in the blend has poor bioavailability (~4%) and dilutes the higher-quality citrate and bisglycinate forms
- -Third-party testing not confirmed per product specs
- -Premium Viridian pricing may not offer the best cost-per-mg versus pure bisglycinate competitors
- -One reviewer reported mild stomach discomfort during initial use
Best For
Watch Out
- !Magnesium oxide inclusion reduces overall bioavailability — pure bisglycinate alternatives may deliver more elemental magnesium per dose
- !Start with a lower dose if you have a sensitive digestive system — magnesium can have a mild laxative effect initially
- !Not third-party tested — users requiring NSF or Informed Sport certification should look elsewhere
What is High Potency Magnesium 300mg 120 Capsules?
High Potency Magnesium 300mg 120 Capsules is a magnesium product by Viridian in capsule form, scoring 71.0/100 on AIScored.
- • TRIPLE FORMULATION FOR EFFECTIVENESS: This high potency magnesium supplement combines magnesium citrate, oxide, and bisglycinate forms to ensure optimal absorption and utilisation by the body.
- • Formulated based on human clinical data, each capsule delivers a potent dose to support overall vitality.
- • SUPPORTS 300+ ENZYME REACTIONS: Magnesium is crucial for over 300 enzymatic processes in the body, playing a vital role in energy production, muscle function, and nerve transmission.
- • This formula provides essential support to maintain optimal bodily functions and wellbeing.
- • ESSENTIAL MINERAL FOR VITALITY: Known as the ‘spark of life’, magnesium helps with maintaining normal heart health and muscle contraction by contributing to normal protein synthesis, normal functioning of the nervous system and electrolyte balance.
- • This high potency formula ensures you receive sufficient daily intake to support your active lifestyle.
- • BIOAVAILABILITY AND ABSORPTION: The combination of Viridian magnesium citrate, oxide, and bisglycinate enhances bioavailability, ensuring that your body absorbs and utilises this essential nutrient effectively.
- • Containing 100% active ingredients, this magnesium 300mg supplement is formulated by nutrition experts to meet stringent quality standards.
- • COMPLETE SATISFACTION: Like every Viridian supplement, Viridian High Potency Magnesium 30 Vegan Capsules is fully considered from the seed to the recycling bank with 130 quality checks.
- • Our customer service team and qualified nutritionists, based in Northamptonshire, are available to support you.
- • Our range is also stocked in independent health stores across the country.
Is High Potency Magnesium 300mg 120 Capsules Independently Tested?
No Third-Party Testing Visible
We could not find evidence of independent third-party testing for this product. This doesn't mean it's unsafe, but independent verification provides additional assurance.
How We Score Supplements
Our methodology analyses review data, ingredient science, and product information, then scores each product on a 0-100 scale across evidence-based categories:
Effectiveness
How well the product delivers its claimed benefits, based on reviews and ingredient evidence.
Ingredient Quality
Bioavailable forms, clinically effective dosages, clean label, minimal fillers.
Value for Money
Price relative to ingredient quality, dosage count, and effectiveness.
Side Effects Profile
Higher score = fewer side effects. 100 means virtually no adverse reactions reported.
Certifications & Testing
Third-party lab testing, GMP certification, and independent quality verification.
Overall Score
Weighted combination of all factors. Our bottom-line recommendation.
Price History (90 days)
Quick Facts
- Form
- Capsule
- Vegan
- No
Frequently Asked Questions
Is High Potency Magnesium 300mg 120 Capsules worth buying in 2026? ▼
What are the pros and cons of High Potency Magnesium 300mg 120 Capsules? ▼
Is High Potency Magnesium 300mg 120 Capsules third-party tested? ▼
What the Data Says About Magnesium
Why is magnesium oxide less effective than glycinate?
Oxide scores 21 points lower than glycinate in our testing — and it's not close on ingredient quality either. Across 17 magnesium products in our database, glycinate averages 74.3/100 overall. Oxide sits at 53/100. That's a gap you can feel.
The ingredient quality difference is even starker: 83.3 for glycinate vs 37.0 for oxide. A 46.3-point gap. The best glycinate in our database, Solgar Magnesium Glycinate 400mg, scores 80/100 overall with 88/100 on ingredient quality. The oxide product (Nature Made) manages just 52 on effectiveness and 37 on ingredient quality.
The reason is bioavailability. Magnesium oxide has roughly 4% absorption — most of it passes straight through your gut unused. Glycinate is chelated (bound to the amino acid glycine), which your intestines absorb much more efficiently. You also get fewer digestive side effects, since unabsorbed magnesium in the gut is what causes the laxative effect oxide is known for.
Oxide is cheap, which is why it's still everywhere. But cheap per pill means nothing if your body can't use it. Glycinate or citrate (avg 74.5/100) are both better choices.
Which form of magnesium is best for sleep, anxiety, or muscle cramps?
Glycinate for sleep and anxiety. Citrate for cramps. L-threonate for brain function. Each form has a different strength, and our scores back this up.
Sleep and anxiety → Glycinate. Averaging 74.3/100 across our database, with the best (Solgar Glycinate 400mg) hitting 80/100. Glycine, the amino acid it's bound to, acts as an inhibitory neurotransmitter — it calms your nervous system on its own. That's a two-for-one benefit you don't get from other forms. Thorne Bisglycinate (74/100) is another solid option at a lower dose.
Muscle cramps → Citrate. Averaging 74.5/100 overall with 85.0 on ingredient quality. Citrate absorbs well and is gentler on your wallet than glycinate. Solgar Citrate leads the pack at 77/100. If cramps are your main issue, this is the practical choice.
Brain function → L-Threonate. Life Extension Neuro-Mag scores 73/100. This is the only form shown to meaningfully raise magnesium levels in the brain by crossing the blood-brain barrier. It's pricier, but nothing else does what it does.
All-round absorption → Doctor's Best High Absorption tops our entire magnesium database at 82/100 overall (83 effectiveness, 88 ingredient quality) using chelated magnesium.
The one form to skip? Oxide at 53/100. Its 4% absorption rate makes it a poor choice no matter what you're taking it for.
Disclaimer: AIScored provides research-backed summaries based on publicly available reviews and product information. This is not medical advice. Always consult a healthcare professional before starting any supplement regimen. Affiliate links may earn us a commission at no extra cost to you.
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