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💰 Exposes the value trick  ·  Free calculator

Cost-Per-Effective-Dose Calculator

A "cheap" magnesium oxide at $12 costs more per absorbed milligram than $28 magnesium glycinate. Enter any supplement's details to find its true cost-effectiveness.

Calculate cost per effective dose
The value illusion explained

Why "cheap" often costs more

Form Absorption Typical Price Cost/100mg absorbed
Key insight

Supplement labels often show the total compound weight — not the bioavailable amount. A 500mg magnesium oxide tablet sounds impressive but delivers only ~20mg of absorbed magnesium (4% bioavailability). A 200mg magnesium glycinate capsule delivers ~160mg absorbed magnesium (80% bioavailability) — 8× more benefit per dollar at a modest price premium.

The same principle applies across: zinc (oxide vs picolinate), omega-3 (ethyl ester vs rTG), curcumin (standard vs enhanced), vitamin B12 (cyano vs methyl), and iron (sulfate vs bisglycinate).

Does bioavailability always determine value?
Bioavailability is the primary driver of cost-effectiveness, but not the only factor. Other considerations: dose frequency (some low-bioavailability forms like creatine monohydrate are so cheap that even with loading doses, the per-gram cost beats alternatives), tolerability (magnesium oxide's low bioavailability also means laxative effects — that's sometimes the goal), and form-specific benefits (magnesium glycinate's glycine component provides independent sleep/anxiety benefits beyond magnesium content).
Is creatine HCl worth the extra cost?
No — for most people. Creatine HCl is marketed as requiring a smaller dose (2–3g vs 5g monohydrate) due to better water solubility. However, no RCT has shown creatine HCl produces equivalent muscle creatine saturation at these smaller doses. Creatine monohydrate has 1,000+ RCTs supporting it at 3–5g/day. HCl costs 5–10× more per effective dose with no proven performance advantage. The ISSN explicitly recommends monohydrate.