Common biases and scaling between species

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The research peptide literature has recognizable bias patterns. Detecting them does not invalidate a study, but it does adjust how much can be asked of it.

Warning signs

• Concentration in a single group. When most of the publications on a compound come from the same laboratory, the lack of independent replication is the main limitation (BPC-157 and the bioregulators of the St. Petersburg school are documented examples).
• Publication bias. Positive results are published more than negative ones; the visible literature overestimates the effect.
• Small samples. A large effect in a small group has wide confidence intervals and usually shrinks when replicated.
• Single dose or short exposure. It says nothing about repeated or prolonged exposure.
• Unverified compound identity. If the study does not document the purity and identity of the material used, the result is hard to attribute.
• Undeclared conflicts of interest.

From animal to human dose: why you do not divide by weight

An effective per-kilo dose in a mouse is not equivalent to the same per-kilo dose in a person. Metabolism scales allometrically, roughly with body surface area. That is why regulatory agencies use conversion factors based on body surface area to estimate the human equivalent dose used to set the starting dose of a first-in-human trial, always with an additional safety margin.

That conversion is a clinical trial design tool, not a way to derive doses for use: it does not incorporate the differences in receptors, pharmacokinetics and toxicity between species, which are only known through studies in humans.

Educational content for scientific purposes. It distinguishes preclinical from clinical evidence and is not medical advice, diagnosis or a recommendation for use. NeoPeptidos products are sold labelled for research use only (RUO).