Evidence-based supplementation
We don't stock supplements because they're popular — we stock them because the science supports them. Every product passes our evidence threshold before it reaches our shelves.
Our evidence standards
We only stock supplements where at least two independent peer-reviewed RCTs (randomised controlled trials) support the claimed benefit at the labelled dose. Anecdotal evidence alone is not sufficient.
The dose in every product is cross-referenced against clinical literature. A supplement must contain the effective dose used in studies — not a token amount for label marketing.
For each ingredient, we assess bioavailability data across different forms (e.g. glycinate vs oxide for magnesium; D3 vs D2 for vitamin D) and specify the most effective form.
We adhere strictly to the GB Nutrition and Health Claims Register. We do not permit disease claims or unauthorised medicinal statements on any product page.
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Apply for VIP →Key ingredients explained
Vitamin D3 (Cholecalciferol)
Supports immunity, bone density, and mood — especially vital in the UK's low-sunlight climate.
Converts to calcitriol, an active hormone that binds to vitamin D receptors in over 200 cell types. Regulates calcium absorption, immune cell function, and neurotransmitter synthesis.
Cochrane reviews and over 3,000 clinical studies. NHS recommends supplementation from October–March for all UK adults.
D3 (cholecalciferol) — 87% more effective at raising serum levels than D2. Pair with K2 (MK-7) to direct calcium to bones.
1,000–2,000 IU daily maintenance; 3,000–4,000 IU to correct deficiency
Omega-3 (EPA & DHA)
Anti-inflammatory, heart-protective, and essential for brain structure and function.
EPA (eicosapentaenoic acid) modulates inflammation via eicosanoid pathways. DHA (docosahexaenoic acid) makes up ~30% of brain fatty acid content and is critical for neuronal membrane integrity.
30+ years of cardiovascular research. REDUCE-IT trial (2018) showed high-dose EPA reduced major cardiovascular events by 25% in high-risk patients.
Triglyceride (TG) or re-esterified triglyceride (rTG) form for highest bioavailability. Look for EPA+DHA content, not just total fish oil weight.
500mg–1,000mg EPA+DHA daily for general health; 2–3g for anti-inflammatory purposes
Magnesium Glycinate
Required for 300+ enzymatic reactions. Most adults are deficient. Critical for sleep, energy, and stress.
Magnesium acts as a cofactor in ATP synthesis, DNA repair, and protein production. Activates GABA-A receptors (calming neurotransmitter). Required to activate vitamin D. Glycine component independently promotes sleep and reduces anxiety.
A 2016 review of 40 studies found magnesium deficiency associated with hypertension, diabetes, and cardiovascular disease. Multiple RCTs confirm improved sleep quality with supplementation.
Glycinate or bisglycinate for sleep/anxiety. Malate for energy. Citrate for general use. Avoid oxide (only 4% bioavailability).
200–400mg elemental magnesium daily, ideally 1–2 hours before bed
Creatine Monohydrate
The most studied sports supplement in existence. Proven to improve strength, power, and cognitive function.
Saturates phosphocreatine stores in muscle and brain. Replenishes ATP more quickly during high-intensity effort. Crosses the blood-brain barrier to support cognitive energy metabolism.
1,000+ peer-reviewed studies. Consistent 5–15% improvement in high-intensity exercise performance. Emerging evidence for memory, cognitive fatigue, and neuroprotection.
Creatine monohydrate — the most studied and cost-effective form. No evidence that HCL or buffered forms are superior.
3–5g daily. No loading required (saturates in 3–4 weeks). Take indefinitely with no cycling needed.
Ashwagandha (KSM-66)
Clinically validated for cortisol reduction, stress resilience, and sleep quality.
Withanolides (active compounds) modulate the hypothalamic-pituitary-adrenal (HPA) axis, reducing cortisol output under stress. Also shows GABA-mimetic activity and may inhibit stress-induced dendritic atrophy.
Multiple RCTs using KSM-66 and Sensoril extracts demonstrate significant reductions in cortisol (up to 27%), improved sleep, and reduced anxiety vs placebo.
KSM-66 (full-spectrum root extract, 5% withanolides) or Sensoril (root + leaf, 10% withanolides). Avoid cheap root powder with undefined withanolide content.
300–600mg standardised extract daily. Evening dosing recommended for sleep benefits.
L-Theanine
Promotes calm focus without sedation. Synergises powerfully with caffeine.
Crosses the blood-brain barrier and increases alpha brainwave activity (associated with relaxed alertness). Modulates GABA, serotonin, and dopamine neurotransmission. Inhibits L-glutamic acid uptake, reducing neuronal excitation.
Well-established in clinical literature. 200mg L-theanine + 100mg caffeine combination consistently outperforms either alone in attention and cognitive performance tasks.
L-Theanine (standard amino acid). Suntheanine is a patented pure form used in most research.
100–200mg on its own; 200mg with 100mg caffeine for focused productivity
Zinc (Bisglycinate)
Critical for immune function, testosterone production, wound healing, and taste/smell.
Structural component of 300+ enzymes. Regulates T-cell and NK cell function. Required for aromatase inhibition (helps maintain testosterone:oestrogen balance). Essential cofactor for thyroid hormone synthesis.
Cochrane meta-analysis: zinc supplementation reduces cold duration by 33%. Studies show zinc supplementation increases testosterone in deficient men.
Zinc bisglycinate or citrate for best absorption. Avoid zinc oxide (poor bioavailability). Take away from iron supplements (compete for absorption).
8–15mg elemental zinc daily. Don't exceed 25mg long-term without medical supervision (copper depletion risk).
Collagen Peptides
Supports joint cartilage, skin elasticity, bone density, and gut lining integrity.
Hydrolysed collagen peptides are absorbed as dipeptides/tripeptides that accumulate in cartilage and skin. Stimulate fibroblasts to produce endogenous collagen, hyaluronic acid, and elastin. Proline and glycine content supports connective tissue repair.
Meta-analyses confirm improvement in joint pain (particularly knee OA) and skin hydration/elasticity. 10g/day for 24 weeks shows significant cartilage improvements in athletes.
Hydrolysed collagen (peptides) — far more bioavailable than whole collagen. Type I/III for skin; Type II for joints. Take with vitamin C for collagen synthesis support.
10–15g daily, ideally with 50–100mg vitamin C
The information on this page is for educational purposes only and does not constitute medical advice. All Medibro products are food supplements, not medicines. They are not intended to diagnose, treat, cure, or prevent any disease. Consult your GP or pharmacist before starting any supplement regimen, particularly if you take prescription medication, are pregnant, or have a health condition.
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