Supplements A–Z (2026): Evidence-Based Comparison Guides
Every supplement we cover, in one place. Each guide compares the real forms, gives evidence-based dosing, and ranks products by cost per clinically-effective dose — with every clinical claim linked to its primary source on PubMed. We say so plainly when the evidence is weak.
Magnesium
Forms compared, sleep/anxiety/cramps picks, dosage, deficiency signs.
Vitamin D
D2 vs D3, dosing (1000–5000 IU), K2 pairing, deficiency.
Omega-3
EPA vs DHA, triglyceride vs ethyl ester, best fish oil.
Iron
Ferrous sulfate vs bisglycinate, low ferritin, tolerability.
Calcium
Citrate vs carbonate, absorption with/without stomach acid.
Zinc
Forms, copper balance, immunity and colds, upper limits.
Vitamin B12
Methylcobalamin vs cyanocobalamin, energy, deficiency risk.
Vitamin C
Forms, the absorption ceiling, immune evidence.
Ashwagandha
KSM-66 vs Sensoril vs generic, stress, sleep.
Probiotics
Strain-specific evidence, condition matching.
Creatine
Monohydrate vs HCl, dosing, what actually works.
Berberine
Dosing, dihydroberberine, blood sugar, safety.
Biotin
Hair and nails evidence, dosing, lab-test interference.
Curcumin
Bioavailability problem, enhanced forms, joint pain.
CoQ10
Ubiquinol vs ubiquinone, absorption, statins.
NAC
Liver/glutathione and mental health, dosing.
Collagen
Types, skin and joint evidence, dosing.
Methylfolate
Vs folic acid, MTHFR, pregnancy dosing.
How we compare supplements
We pull product label data from the NIH Dietary Supplement Label Database, clinical evidence from PubMed systematic reviews, and third-party certifications from USP and NSF. Read our methodology and editorial standards.