How we evaluate a supplement ingredient before it goes in a formula
Disclosure: Three Whole Health owns the FemiCore and Yu Sleep brands mentioned in this article. This content is educational and is not medical advice. See our editorial policy.
Walk down any supplement aisle and you will see labels with fifteen ingredients and no explanation of why a single one of them is there. At Three Whole Health we think that is backwards. An ingredient earns its place in a formula, and this article explains the five questions we use to decide.
1. Is there human evidence?
The first filter is whether the ingredient has been studied in people. Cell-culture and animal studies are useful for understanding a mechanism, but they cannot tell you whether a capsule will do anything for a person. We look for:
- Randomized controlled trials (RCTs) in adults
- Systematic reviews or meta-analyses that pool multiple trials
- Guidance from bodies such as the NIH Office of Dietary Supplements (ODS) or the National Center for Complementary and Integrative Health (NCCIH)
Example: melatonin has a large body of human trials on sleep onset, which is why it anchors Yu Sleep. GABA, by contrast, has more limited human data, so we include it as a supporting ingredient rather than making it the headline.
2. Does the evidence match our customer?
A positive trial is only relevant if the people in it resemble the people who will buy the product. Cranberry is a good example. Some of the strongest cranberry studies were done in hospital patients with catheters or in children with recurrent infections. Those results tell us less about a healthy adult woman with occasional urgency than a trial in that exact population would. When we cite evidence on a brand page, we try to say who was studied.
3. Is the studied form available?
Ingredients are not interchangeable. "Cranberry" can mean juice, whole-fruit powder, or an extract standardized to a specific amount of proanthocyanidins (PACs), the compounds thought to interfere with bacterial adhesion. Most of the encouraging research used products with a defined PAC content, which is why FemiCore specifies a 30% PAC extract instead of generic cranberry powder.
The same logic applies to minerals. Magnesium oxide is cheap but poorly absorbed; magnesium glycinate costs more and is gentler on the stomach. Yu Sleep uses the glycinate form for that reason.
4. Is the studied dose practical?
An ingredient that only works at a dose that cannot fit in a daily serving should not be added at a fraction of that dose for the sake of the label. This is what the industry calls "fairy dusting," and it is one of the reasons we avoid long ingredient lists.
The reverse also matters. More is not always better. Trials on melatonin show that low doses of around 0.3 to 1 mg can restore night-time blood levels, while higher doses are more often linked to next-day drowsiness. We explain that decision in Why we chose 0.9 mg of melatonin.
5. Is the safety profile acceptable?
Finally we review known side effects, interactions and contraindications. This determines both whether we include an ingredient and what we must tell customers. Berberine, for instance, can affect blood sugar and interacts with some medications, so FemiCore's page tells people on diabetes or blood-thinning medication to check with a clinician first. 5-HTP in Yu Sleep triggers a similar note for anyone on antidepressants.
What this looks like in practice
| Ingredient | Product | Human evidence | Form we use | Safety note |
|---|---|---|---|---|
| Melatonin | Yu Sleep | Extensive RCTs on sleep onset | 0.9 mg, sublingual | Drowsiness; avoid driving |
| Cranberry extract | FemiCore | Multiple RCTs, mixed but encouraging for recurrent UTI risk | Standardized to 30% PACs | Possible interaction with warfarin |
| Magnesium | Yu Sleep | Small RCTs on sleep quality in older adults | Glycinate | Loose stools at high doses |
| L. crispatus | FemiCore | Clinical studies on urogenital microbiome | Multi-strain blend | Generally well tolerated |
Why we publish this
We would rather lose a sale to someone who reads this and decides our product is not for them than win one on a promise we cannot keep. If you have questions about a specific ingredient, get in touch. Our full standards are on the How We Work page.
Sources
- National Institutes of Health, Office of Dietary Supplements. Dietary Supplements: What You Need to Know. ods.od.nih.gov
- National Center for Complementary and Integrative Health. Melatonin: What You Need To Know. nccih.nih.gov
- National Center for Complementary and Integrative Health. Cranberry. nccih.nih.gov
- U.S. Food and Drug Administration. Current Good Manufacturing Practice (CGMP) for Dietary Supplements, 21 CFR Part 111. fda.gov
† These statements have not been evaluated by the Food and Drug Administration. Our products are not intended to diagnose, treat, cure, or prevent any disease.