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Peptide Evidence Registry

Neuro & cognitive · Reproductive & sexual health · Metabolic & endocrine

Phoenixin-20

A 20-amino-acid neuropeptide studied in animals and cultured cells across reproductive, gut and metabolic biology. No human trial evidence.

L2Animal / lab studiesResearch / unapproved supplyPreclinical
How settled this rating is:
very-low confidence in the current evidence rating
Routes studied:
Not established · Subcutaneous injection, Nasal (marketed but never approved)
Also known as:
PNX-20, phoenixin, SMIM20-derived peptide
Last reviewed:
2026-09-21
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Evidence passport

Phoenixin-20

A one-screen evidence identity for this compound. These fields describe research maturity, confidence and legal status. They are not a safety guarantee, efficacy percentage or recommendation.

Reviewed 2026-09-21
Evidence level
L2Animal / lab studies
Confidence
Very low confidence in rating
Regulatory status
Research / unapproved supply
Development status
Preclinical

Evidence strength

Human efficacy evidence3 of 100 evidence strength

Higher = more and better-quality human evidence. It does not mean the effect is bigger or that the compound works for you.

Human safety evidence3 of 100 evidence strength

Higher = more mature, better-documented human safety data. It does not mean the compound is safer than one with a lower number.

The 0-100 values rate the strength and maturity of evidence, not how effective or safe the compound is.

Evidence base
Mostly animal and laboratory research
Furthest established stage
Preclinical
Human research maturity
Preclinical — animal physiology and cultured-cell work only
Source curation
Sources fully curated

Routes recorded

SC injection· unapprovedNasal· unapproved

Most of this evidence comes from animals and cells

The supporting research for Phoenixin-20 is predominantly preclinical (Level 1–2). That is a legitimate starting point for science and a poor basis for personal decisions. Human results are not simply a scaled-up version of mouse results.

Overview

Human efficacy evidence strength3 of 100 evidence strength

Higher = more and better-quality human evidence. It does not mean the effect is bigger or that the compound works for you.

Preclinical (animal / lab) evidence strength45 of 100 evidence strength

Higher = more animal, tissue or cell research. Preclinical results are a starting point, not proof of a human benefit.

Human safety evidence strength3 of 100 evidence strength

Higher = more mature, better-documented human safety data. It does not mean the compound is safer than one with a lower number.

How to read these scores

Every number here rates the evidence, not the compound. They are editorial 0-100 strength ratings, not percentages, and not a rating out of five stars.

  • Human efficacy evidence strength — Higher = more and better-quality human evidence. It does not mean the effect is bigger or that the compound works for you.
  • Preclinical evidence strength — Higher = more animal, tissue or cell research. Preclinical results are a starting point, not proof of a human benefit.
  • Human safety evidence strength — Higher = more mature, better-documented human safety data. It does not mean the compound is safer than one with a lower number. A score of 80 does not mean “80% safe”.
  • Evidence level (L0-L5) — the strongest type of study behind the compound, from anecdote (L0) to large replicated human trials (L5). It is a description of the study evidence, not a quality, safety or recommendation rating.
  • Confidence — how likely we think it is that this rating changes as new research lands. Low confidence means the picture is unsettled, not that the compound is bad.

None of these ratings is medical advice, a safety guarantee, or a recommendation to use anything. How we grade evidence.

How far human research has progressed: Preclinical — animal physiology and cultured-cell work only

Routes & formulations

Marketed / research routes — never approved

SC injection· unapprovedNasal· unapproved

Published work uses laboratory administration in animals, including central injection. Routes marketed online are not studied human routes.

Route availability is not evidence of efficacy, and evidence from one route does not transfer to another. The Registry never provides dosing or sourcing information.

Peptide lifecycle

  1. Discovery

  2. Preclinical

    Furthest established stage

  3. Phase I

  4. Phase II

  5. Phase III

  6. Approved

Preclinical

An active academic research area with no pharmaceutical development programme established in our record.

Last documented development: 2020-2021 — neuronal and gastric endocrine research reports

What it is

A genuine peptide: the 20-amino-acid active isoform of phoenixin, cleaved from the small integral membrane protein SMIM20. It was first described in reproductive neuroendocrinology and has since been reported to act across brain-gut signalling, appetite and metabolic regulation, which is why it is described as pleiotropic.

What people claim

  • Boosts mitochondrial biogenesis and brain energy
  • Improves libido and reproductive function
  • Appetite and metabolic regulation

What the evidence actually says

Phoenixin-20 is real biology with a broad and still-unsettled picture. Reported effects on reproductive signalling, gastric endocrine function and metabolic hormones come from animal and cell experiments. The mitochondrial-biogenesis finding people cite most often was produced in cultured neuronal cells via CREB and PGC-1α signalling — cell-culture evidence, not human clinical evidence, and it should never be presented as such.

Related evidence

Useful next reads based on this compound — not recommendations.

Human evidence

  • No controlled human trial of phoenixin-20 was identified in our curated record.
  • Human studies in this area measure circulating phoenixin levels in various conditions. An association between a naturally occurring peptide level and a condition is not evidence that injecting the peptide helps.

Preclinical evidence

  • In cultured neuronal cells, PNX-20 promoted mitochondrial biogenesis through CREB and PGC-1α signalling (PMID 32236796). This is cell-culture evidence.
  • Work on gastric endocrine cells and gut metabolic hormone signalling describes a brain-gut role (PMID 33862165).
  • Broader animal and review literature covers reproductive axis signalling, food intake, anxiety-like behaviour and metabolic effects (PMID 33171667, PMID 29542680).

Animal and cell findings are Level 1–2 evidence.

Mechanism and pathways

  • Cleaved from SMIM20 and acting as a signalling peptide in the hypothalamus and peripheral tissues.
  • Reported downstream CREB and PGC-1α activation is the proposed route to mitochondrial biogenesis in neuronal cells.
  • The receptor through which it acts is not firmly established, which limits how confidently any effect can be attributed.

Safety and unknowns

  • No human safety data exist in our curated record.
  • A peptide acting across reproductive, appetite and stress pathways has obvious potential for unintended effects, none of which has been characterised in people.
  • Research-market material is unregulated and its identity and purity are unverified.

Cancer relevance

This section covers questions raised by how the compound works in the body, plus anything regulators and trial teams keep an eye on. It is not a statement that this compound causes cancer — for most compounds here, no human data exist in either direction.

No established human signal

Not established. No human data exist in either direction.

Regulatory status

Regulatory decisions apply to specific jurisdictions, products, formulations and indications. An approval elsewhere is not automatically an approval in your country.

Check the regulatory note and linked primary sources for jurisdiction-specific details.

Not an approved medicine and not established in human trials in our curated record. It is a research peptide used to study a signalling system.

Evidence grade

L2Animal / lab studiesVery low confidence in rating

Documented compound-specific animal or laboratory outcome findings, without qualifying human evidence for the assessed benefit.

What would change our rating?

  • A Phase 1 human safety and pharmacokinetic study.
  • Settled receptor pharmacology, and animal outcome data in a defined indication.

References and sources

Source transparency

A provenance snapshot of this profile. Counts show what kinds of sources are cited, not how much scientific weight each source deserves.

Sources fully curated
Last editorial review
2026-09-21
Recently reviewed · 25 days ago
Linked curated sources
4
Sources still pending
0
External specialist reviews
0
None recorded for this profile
Peer-reviewed: 4

Review provenance

Registry editorial review: Colin Jackson-White, creator and editor, who is not a doctor or clinician. External specialist review is credited only when a named reviewer has completed a review of this exact profile.

Literature-discovery and AI tools may help locate or challenge candidate evidence, but they are not counted as evidence sources here. Registry judgements are tied to the underlying papers, trial records, regulator documents and official study records.

Source hierarchy: regulatory documents and trial registries first, peer-reviewed work next, sponsor material flagged as non-independent. We never use supplier or clinic marketing as evidence, and where a verified source has not yet been curated we say so rather than inventing one.

Evidence change history

These entries record changes to our assessment of the published evidence — not changes to the compound itself.

No recorded changes yet. Baseline position set on 2026-09-21.