Supplement & Nutrient Encyclopedia

Supplement articles

Plain-English answers to the supplement questions people search most, each built on graded human trials with every number cited. Each article links back to its full monograph.

Ashwagandha

Ashwagandha for Stress and Sleep: What the Trials Found, and Why the Results Vary So MuchAshwagandha is the internet’s favorite calm-down herb. The trials do point the right way for stress and sleep, but they are small, short and wildly inconsistent. Here is what that means for you.
Ashwagandha Side Effects: The Liver, Thyroid and Pregnancy Warnings Behind Denmark’s BanMost people in trials tolerated ashwagandha fine for a few months. But a handful of rare, real risks explain why one European country banned it and others issued warnings.

Berberine (vs dihydroberberine)

Beta-alanine

Caffeine (capsules, gum and anhydrous powder)

Calcium (carbonate vs citrate)

Carnitine (L-carnitine, L-carnitine L-tartrate, acetyl-L-carnitine)

Choline (bitartrate vs alpha-GPC vs phosphatidylcholine)

Citrulline (L-citrulline and citrulline malate)

Collagen peptides

CoQ10 (ubiquinol vs ubiquinone)

Cordyceps

Creatine monohydrate

Electrolytes and sodium (salt tablets and electrolyte drinks)

Fenugreek

Folate (methylfolate vs folic acid)

HMB (beta-hydroxy-beta-methylbutyrate)

Iodine (potassium iodide, kelp)

Iron (ferrous sulfate vs bisglycinate vs other forms)

L-theanine

Lion's mane mushroom

Magnesium

How Much Magnesium Is Too Much? The 350 mg Rule, the Label Trap and Who Should Be CarefulMagnesium is one of the safest-feeling supplements on the shelf, which is exactly why people stack three products and blow past the limit without noticing. Here is the math.

Magnesium glycinate

Magnesium Glycinate vs Citrate: The Calm One, the Bathroom One, and What the Label Really HoldsGlycinate is the bedtime favorite; citrate has a reputation for keeping you regular. The evidence for each is thinner and more interesting than the marketing, and the elemental math changes how much you are really getting.

Melatonin

NAC (N-acetylcysteine)

Nicotinamide riboside (NR)

NMN (nicotinamide mononucleotide)

Omega-3 (fish oil, krill oil, algal oil)

Potassium (chloride vs citrate vs gluconate)

Probiotics

Psyllium

Quercetin

Reishi mushroom

Resveratrol

Rhodiola rosea

Saffron

Selenium (selenomethionine vs selenite)

Spermidine

Taurine

Tongkat ali

Turmeric and curcumin

Vitamin A (retinyl palmitate vs beta-carotene)

Vitamin B12 (methylcobalamin vs cyanocobalamin)

Vitamin B6 (pyridoxine vs P5P)

Vitamin B6 Toxicity: How a “Harmless” Vitamin Can Cause Tingling FeetB6 hides in energy drinks, B-complexes, magnesium blends and sleep formulas. High intakes over months can damage nerves. Here is the limit and what the research says about forms.

Vitamin C (ascorbic acid vs buffered vs liposomal)

Vitamin D3 vs D2

Vitamin E (natural d-alpha vs synthetic dl-alpha tocopherol)

Vitamin K2 (MK-7 vs MK-4)

Whey protein (and other protein powders)

Zinc (picolinate vs gluconate vs bisglycinate)

Educational information only, not medical advice. Dietary supplements are not intended to diagnose, treat, cure or prevent any disease.