The supplement market is one of the most aggressively marketed and least regulated consumer categories in existence. The gap between what is claimed on a product label and what the clinical evidence supports is vast — and the gap between the dose in the product and the dose that produces the effect in the research is often wider still. This guide is built around what the science actually says: which supplements have the strongest evidence, at what doses, in what forms, and why form and dose matter far more than brand.

Protein: the non-negotiable foundation

Dietary protein is the single most important nutritional variable for muscle building, body composition, and metabolic health — and for many people, particularly those who train, it remains chronically under-consumed relative to their needs. The current evidence supports 1.6 to 2.2 grams of protein per kilogram of bodyweight daily for muscle protein synthesis optimisation in active individuals — a target most people eating standard Western diets fall significantly short of. Whey protein concentrate and isolate are the most bioavailable and fastest-digesting protein supplements, making them the optimal post-training choice. Casein protein digests slowly and delivers a sustained amino acid release over four to seven hours, making it the optimal pre-sleep supplement for overnight muscle protein synthesis. Plant-based proteins (pea, rice, and hemp in combination) provide a complete amino acid profile for those avoiding dairy. Kingdom Labs stocks all three protein types across flavour profiles with no artificial sweetener undisclosed in the ingredient list.

Creatine monohydrate: the most evidenced supplement on earth

Creatine monohydrate has more peer-reviewed clinical research supporting its safety and efficacy than any other sports supplement available — over 500 studies and counting. It works by increasing phosphocreatine stores in skeletal muscle, which are the primary fuel source for short-duration, high-intensity efforts: strength training, sprinting, explosive athletic movements. At 3 to 5 grams daily, it consistently improves strength output, power production, training volume capacity, and recovery speed between sets. It also has a growing evidence base for cognitive benefits — particularly in sleep-deprived individuals and older populations — through its role in brain energy metabolism. No loading phase is required: 3 to 5 grams daily reaches saturation in the muscle over two to three weeks. Micronised creatine monohydrate is the optimal form — higher surface area for faster dissolution, identical efficacy to standard creatine at the same dose. Kingdom Labs stocks micronised creatine monohydrate at 3g and 5g serving sizes.

Vitamin D3 & K2: the combination that defines modern supplementation

Vitamin D3 (cholecalciferol) at 2000 to 4000 IU daily addresses the widespread deficiency that suppresses immune function, impairs muscle recovery, reduces testosterone production, compromises bone density, and significantly increases risk of seasonal mood disorders. Vitamin K2 MK-7 (menaquinone-7) — the bioavailable long-acting form of K2 — directs the calcium mobilised by vitamin D into bone tissue rather than arterial walls, making it the essential co-supplement for anyone taking D3 above 1000 IU daily. The D3/K2 combination at 4000 IU D3 and 100mcg K2 MK-7 daily is the current evidence-supported protocol. Most over-the-counter multivitamins provide 400 to 800 IU of D2 — the less bioavailable form at an insufficient dose. Kingdom Labs stocks D3+K2 MK-7 in the bioavailable forms at clinical doses only.

Magnesium glycinate: the most impactful single addition

Magnesium is a cofactor in over 300 enzymatic reactions in the body — and insufficiency (distinct from clinical deficiency) is extremely prevalent in Western populations eating processed diets. The consequences are diffuse: poor sleep quality, elevated resting heart rate, muscle cramps, constipation, anxiety, and impaired recovery from exercise. The form is critical: magnesium oxide — the most common form in cheap supplements — has approximately 4% bioavailability and primarily functions as a laxative at higher doses. Magnesium glycinate (magnesium bound to glycine) has bioavailability of 80% or above, is gentle on the gut, and delivers the additional calming effect of glycine on the nervous system. At 300 to 400mg daily before bed it is the single most impactful sleep and recovery supplement available at any price point. Kingdom Labs stocks magnesium glycinate at therapeutic doses in every-night use format.

Ashwagandha KSM-66: the adaptogen with clinical evidence

Ashwagandha has the most robust evidence base of any commercially available adaptogen — specifically the KSM-66 extract (standardised to 5% withanolides) and the Sensoril extract (standardised to 10% withanolides). Clinical trials at 300 to 600mg daily of KSM-66 show consistent reductions in serum cortisol, improvements in perceived stress scores, increased testosterone in men with below-average baseline levels, and improved sleep quality measured by PSG. The mechanism is modulation of the HPA axis — the hormonal pathway through which the stress response operates — reducing the chronic cortisol elevation that suppresses testosterone, impairs recovery, and degrades sleep quality. Kingdom Labs stocks KSM-66 ashwagandha at the 600mg daily dose used in the clinical literature, not the 100 to 200mg commonly found in blend products where ashwagandha is listed for marketing rather than clinical effect.

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Vitamins, protein powders, creatine, pre-workout, actives, adaptogens, nootropics, and sleep support — all formulated at clinical doses, all transparently labelled, all stocked because the evidence says so. Browse the full Kingdom Labs range and build the stack your kingdom deserves.