Guides
Understanding evidence levels
Every compound page on Healthy Mango shows a four-bar evidence meter. This guide explains what each level means, what it doesn't mean, and how to read a study yourself without needing a research background.
7 minute read · Last reviewed 2026-07-11
What the four bars actually mean
Healthy Mango labels every compound with an evidence tier from D to A. That tier is a summary of the kind and quantity of published human data available for the compound — not a rating of how well it works, and not a recommendation. Tirzepatide, which has multiple published phase-3 trials totaling tens of thousands of participants, sits at A. Retatrutide, with published phase-2 data and ongoing phase-3 trials that have not yet reported, sits at B. A compound with only case reports and small pilot studies would sit at C. A compound supported almost entirely by cell-culture or animal work would sit at D. The tier does not translate to safety, effectiveness, or appropriateness — it describes only what we have to read.
Why we don't collapse it to one number
A five-star rating suggests a total quality score. Evidence isn't a total quality score. A compound with strong evidence for weight loss can still have a limited safety profile at extreme doses, and a compound with weak evidence can still be under active investigation for a rare condition where the alternative is nothing. Reducing that landscape to "3.5 out of 5" hides more than it explains. The four-bar tier keeps a compound page honest about what has and has not been established, without implying a verdict.
The tier answers the question "how much do we know?" — never "should I take this?"
How to read a clinical-trial finding yourself
Check the phase. Phase 1 studies safety. Phase 2 estimates a signal. Only phase 3 tests it against a control at scale.
Look at the sample size. A 40-person open-label trial does not carry the weight of a 2,500-person randomized trial, even if the numbers look similar.
Read the primary endpoint, not the summary. Secondary endpoints and post-hoc analyses can be selectively reported; the primary endpoint was fixed before the trial began.
Check who funded the trial and where it was published. Peer-reviewed publications in journals with an editorial process (NEJM, Lancet, JAMA) carry more weight than press releases or preprints.
Compare the effect size to the confidence interval. A −20 % point estimate with a 95 % CI of −22 % to −18 % is a much stronger signal than −20 % with a CI of −35 % to −5 %.
Frequently asked
Does an A rating mean it's safe?
No. An A means the human evidence about what the compound does is substantial and consistent. Every approved therapy also carries a labeled safety profile with side effects and warnings — the evidence tier does not replace that. Read the Warnings and Clinical Status sections on every compound page.
Does a D rating mean it doesn't work?
No — it means we don't have the human data yet to say either way. Some D-tier compounds are early-stage investigational agents; some are legacy compounds that never attracted a modern clinical program. A D just means the map of published human evidence for this compound is largely blank.
References
- Tirzepatide versus semaglutide once weekly in patients with type 2 diabetes (SURPASS-2)· Frías JP, Davies MJ, Rosenstock J, et al. · 2021
- Tirzepatide once weekly for the treatment of obesity (SURMOUNT-1)· Jastreboff AM, Aronne LJ, Ahmad NN, et al. · 2022
- Continued treatment with tirzepatide for maintenance of weight reduction in adults with obesity (SURMOUNT-4)· Aronne LJ, Sattar N, Horn DB, et al. · 2024
- Triple-Hormone-Receptor Agonist Retatrutide for Obesity — A Phase 2 Trial· Jastreboff AM, Kaplan LM, Frías JP, et al. · 2023
Links open external, peer-reviewed sources. Healthy Mango does not host trial data.
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