How to read a grade against a real product

Why we grade the molecule, not the product

Clinical trials test substances — semaglutide, rapamycin, urolithin A — not specific brands or SKUs. Because every ClinEvident grade is built only from published clinical evidence, the grade can only attach to the thing the evidence is about: the molecule. Grading a product would imply we had evaluated that product's evidence, which usually does not exist separately. So we grade the molecule and list products that contain it as reference information — clearly showing where a product's dose or form matches the trial, and where it does not.

Units & dose

The most common place a product quietly diverges from the evidence is the dose — and the units it is expressed in.

• mg / mcg / g. A thousandfold separates a milligram (mg) from a microgram (mcg). A product listing "500 mcg" of something the trials dosed at "500 mg" delivers a fraction of a percent of the evidence dose.
• IU vs. mg. International Units measure biological activity, not mass, and the IU↔mg conversion is substance-specific — the factor for vitamin D is not the factor for vitamin E. An IU figure cannot be compared to a milligram figure without the correct, substance-specific conversion.
• Elemental vs. salt weight. Many minerals are sold as a salt, and the label weight may describe the whole salt rather than the active element. 500 mg of magnesium oxide is not 500 mg of elemental magnesium — the elemental content is much lower. The evidence usually refers to the elemental amount.

On every graded molecule we show the evidence dose (what the trials used) next to each product's actual dose, so the gap is visible at a glance.

Salt forms

A "salt form" pairs the active molecule with a counter-ion to make it stable or absorbable — magnesium glycinate vs. oxide, metoprolol succinate vs. tartrate, and so on. The salt changes two things that matter for reading a grade: the elemental content per milligram (so the same label weight delivers a different amount of active molecule), and sometimes absorption. Crucially, a trial tested one specific form. When a product uses a different salt than the trials did, the grade does not automatically transfer — the evidence is about the form that was studied.

Enantiomers & isomers

Some molecules exist as mirror-image forms (enantiomers) or other isomers that behave very differently in the body — sometimes one form carries the benefit and another does not. This is not a technicality: it can be the entire point. 17α-estradiol, for example, is a non-feminizing isomer studied in aging research precisely because it differs from ordinary estradiol. When the evidence is about a specific isomer, a product containing a different one is telling a different story, and our grade follows the isomer the trials tested.

Formulation & route

How a molecule is delivered shapes what reaches the body. Extended-release vs. immediate-release, oral vs. injectable, and depot formulations can all change exposure even when the molecule and dose look identical on paper. The question to ask of any product is simple: does its form match what the trials tested? An oral version of a molecule whose evidence comes from injectable trials is not automatically covered by that evidence.

Compounded & novel forms

Compounded preparations and novel synthesis routes can produce a substance that is chemically close to — but not identical with — the trial-tested form, and they are not always held to the same manufacturing standards. We treat this strictly as a question of evidence relevance: where a product uses a compounded or non-standard form, the published evidence for the studied form may not transfer. ClinEvident does not provide synthesis or compounding instructions; we only note when a form differs from the one the evidence is about, and what that means for the grade.

Every term above is applied consistently across the site using standardized vocabulary, so a "salt form" or "evidence dose" means the same thing on every grade.