~3% of FDA drugs have unclear mechanisms
Only about 3% of FDA-approved drugs have genuinely unclear mechanisms of action, making an unknown mechanism a meaningful early red flag for any compound.
Snapshot · The Peter Attia Drive
#403 ‒ Peptides: separating scientific promise from marketing hype
Explore episode
Aug 10, 2026
Where this was said
A five-question framework for evaluating peptides and other drugs
At 7:30 · chapter starts 5:30
The episode's intellectual engine is a five-question framework Peter developed for the original AMA and now refines here. The framework is deliberately bias-resistant: it applies equally to compounds Peter believes in and ones he's skeptical of. Question one — is there a viable mechanism? — is arguably the most important. Without a defined molecular target and a plausible downstream chain, claims about 'boosting energy' or 'reducing inflammation' become marketing language rather than biology. A mechanism also identifies failure modes: a drug might not reach the relevant tissue, might move biomarkers without affecting disease, or might have opposing downstream effects. [1] — Peter Attia "Five questions cut through the noise on any peptide: Is there a viable mechanism? Human evidence? Known safety and dosing? A justifiable ri…" 05:43 Only about 3% of FDA-approved drugs have genuinely unclear mechanisms — making unknown mechanisms a meaningful red flag. The remaining four questions address human evidence, safety and dosing, risk-benefit calibration, and whether a better-characterized alternative exists, each designed to force specificity rather than allowing vague, unfalsifiable claims.
The 5-Question Framework for Evaluating Any Peptide
Five questions cut through the noise on any peptide: Is there a viable mechanism? Human evidence? Known safety and dosing? A justifiable risk-benefit? And is there a better-characterized alternative? Run any compound through these and you'll usually have your answer.
30–50% of phase 1 drugs fail to reach phase 2
Even compounds that clear preclinical testing often fail in humans: 30 to 50% of drugs entering phase 1 trials do not advance to phase 2, frequently because human behavior differs from animal models.
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