Methodology
FairDose is an independent UK comparison tool. We do not rank products by cheapest bottle price. We rank them by useful dose, formula quality, transparency, and value.
In one paragraph
We normalise every product on elemental dose, compare within a single ingredient form, calculate cost per usable serving, and score transparency and clean-label signals out of five each. A combined value score weighs cost (65%) and quality (35%).
We normalise every product on elemental magnesium per serving — the actual amount of magnesium your body receives, not the compound weight on the front of the bottle. A '1,000mg magnesium bisglycinate' label often delivers only 100–200mg of elemental magnesium. We compare the number that matters.
Different magnesium forms (glycinate, citrate, malate, L-threonate, taurate, oxide) are not interchangeable on price or purpose. FairDose compares products within a form — glycinate against glycinate — so the comparison is fair.
We calculate the cost of 200mg of elemental magnesium for every product. This normalised benchmark lets you compare a 60-serving bottle to a 120-serving bottle, or a 100mg-per-cap product to a 200mg-per-cap product, without bottle-size or serving-size tricks.
We score whether the product avoids unnecessary additives, unclear blends, artificial colours, and avoidable fillers — specifically: no magnesium stearate, no titanium dioxide, no proprietary blends, vegan-friendly, and marketed clean-label. This is a buyer preference, not a safety claim.
Independent third-party testing is one of the strongest quality signals a supplement brand can offer. We record whether a product is third-party tested, whether the elemental dose is clearly stated, and whether the country of manufacture is disclosed.
Practitioner-grade positioning, transparent dosage, no proprietary blend, and disclosed manufacturing all feed into a transparency score out of five. A brand can sell a clean product without being transparent — we score both.
Our combined value score is 65% normalised cost per 200mg elemental + 35% quality signals (transparency + clean label). FairDose does not rank products by cheapest bottle price. It ranks them by useful dose, formula quality, transparency, and value.
Disclaimer
FairDose is for informational purposes only and is not medical advice. Product information and prices are manually researched and may change. Always check the retailer's current label, price, allergen information, and suitability before purchasing. Speak to a qualified healthcare professional if you are pregnant, breastfeeding, taking medication, or managing a medical condition.