The Expert Witness Pocket Guide

A field reference for the clinician who testifies in peptide, hormone, and longevity medicine — or who is called to answer for it. Peptide medicine outpaces the law that governs it. This pocket guide maps the medicolegal terrain of that gap for two readers at once: the physician, NP, or PA retained as an expert witness (or facing a board complaint), and the attorney deciding what an expert in this field can credibly say. One issue per two-page spread, in a consistent template: the governing rule, the expert's role, the elements as a court applies them, how the other side will argue it, discovery targets, the cross-examination to expect, and a practice pointer — with each entry labelled SETTLED, MAJORITY, EVOLVING, or NOVEL so unsettled law is flagged, never smoothed over. Seven parts move from expert-witness foundations and the federal regulatory framework through state practice and liability, causation and damages science, the peptide market's commercial chain, dispute-generating molecule profiles, and a practical toolkit of checklists, review protocols, and report language. A companion to The Peptide Pocket Guide: that volume rates the evidence behind seventy peptide therapeutics; this one addresses what happens when that evidence — or its absence — is examined by a court, a licensing board, or a regulator. Prepared for the 2026 edition, with status-dated entries on the field's most perishable regulatory pages.