Sarah Caldwell
From the Clinic to Independent Research
I left private practice in 2022 to dedicate myself full-time to what I’d been doing part-time for three years: independently testing, analyzing, and ranking dietary supplements across the categories I knew best from clinical work — metabolic health, gut microbiome support, testosterone and hormonal balance, energy and adaptogenic compounds, and cognitive function.
The process I developed is straightforward and non-negotiable. Every product I review is purchased at retail — never gifted by a brand, never provided in exchange for coverage. Each formula is used for a minimum of four weeks and assessed against the peer-reviewed literature on its core ingredients. No exceptions. No shortcuts.
Since starting this work, I’ve personally tested more than 200 supplements. The ones that make it to my rankings are the ones that survived that process.
What I Look For
After years of clinical practice and independent testing, I evaluate every supplement against the same five criteria:
Ingredient quality — the specific form of each compound matters as much as the dose. Magnesium glycinate and magnesium oxide are not the same thing. Neither are all forms of berberine, ashwagandha, or omega-3.
Mechanism specificity — does this formula actually target the root cause of the problem it claims to address, or does it just stack popular ingredients and hope something sticks?
Clinical backing — I read the actual studies, not the brand summaries. Dosage used in trials, population studied, effect size, and publication quality all factor into my assessment.
Real-world results — lab evidence is necessary but not sufficient. I track my own response over four-plus weeks and incorporate verified user outcomes from independent sources.
Value and transparency — pricing, money-back guarantee, manufacturing standards, and how honest a company is about what their product can and cannot do.
On Independence and Affiliate Relationships
BestRatedSupps earns a commission when you purchase through links on this site. I think it’s important you know that — and equally important that you know it has never influenced a single ranking or recommendation I’ve published.
The commission structure is the same whether I rank a product first or fifth. My rankings are determined entirely by how a formula performs against my five evaluation criteria. Brands do not pay for placement, do not receive advance notice of reviews, and have no ability to influence my editorial decisions.
If you ever find a ranking that seems inconsistent with the evidence I present, I want to hear about it. The contact page is always open.
My Background
- B.S. in Nutritional Sciences, University of Texas at Austin — 2007
- Certified Clinical Nutritionist (CCN), American Clinical Board of Nutrition — 2010
- 12 years in private clinical practice specializing in metabolic dysfunction and weight management — 2010 to 2022
- Independent supplement researcher and health writer, BestRatedSupps — 2022 to present
- 200+ supplements independently tested across metabolic, gut, hormonal, and cognitive categories — 2019 to present
Independent supplement research you can actually trust. No paid rankings, no sponsored content — just honest analysis from a clinical nutritionist who tests every product herself.