How to Choose an Effective Supplement (Part 1)

Cristina Gall
Jul 25
2 min read

The Core Principles of Dose and Bioavailability: A Look Behind the Curtain

Have you ever felt like the woman above while shopping for a particular supplement? Trying to guess which form of magnesium—oxide, citrate, glycinate..?—is the right one, while a dozen other options sit in judgement.

That magnesium maze is just the tip of the iceberg. Stroll through a supplement shop, or scroll through Amazon or iHerb, and you’ll see hundreds of “ultimate formulas,” each shouting louder than the last.

You're left blind guessing which supplement forms are most effective—if the label discloses them at all.

And because pre-market regulation is minimal, you’re left trusting that each manufacturer has chosen the most evidence-backed form and the right dose. Spoiler: many haven’t.

I know this world intimately because I spend my days dissecting countless supplement labels: cross-checking doses against research studies, comparing the benefits and drawbacks of the various biochemical forms for each nutrient, checking for any red flags on labels, and requesting detailed ingredient and third-party testing data (that brands rarely expect anyone to ask for).

In this guide, I will explain the foundational framework I use for every single supplement evaluation. While my full process is more detailed, mastering these core principles is the first step to taking the blindfold off and choosing supplements with confidence.

The Golden Rule for Supplements

The effectiveness of any supplement can be distilled into one core principle:

Effectiveness = Clinically Proven Dose × High Bioavailability

Think of this as the "golden rule" for choosing effective supplements.

If either factor is zero, your benefit is zero and you've wasted your money. (Let’s make sure that never happens again.)

What’s Next?

Now that you understand the golden rule, we're ready to dive into the details.

In the next two parts of this guide, I will walk you through the five-point quality checklist I use for each and every supplement evaluation, so you can learn to spot true performers (or, if you prefer, let me do the detective work for you).

In Part 2, we will tackle the two most important factors from our equation: how to verify a supplement's Dose and Bioavailability.

See you there!