Evidence review: Open Peptide Project (verified against primary PubMed, ClinicalTrials.gov & FDA records) · Last checked 2026-10-27. ← Back to Evidence Library
Spexin (neuropeptide Q, NPQ): what the evidence says
At a glance
What it is: a 14-amino-acid peptide found by computer search of the human genome in 2007. It acts on galanin receptors 2 and 3. R1, R2
What the evidence says: Animal from lab and animal work, spexin is believed to help regulate appetite and fat storage: injections reduced food intake and body weight in obese mice and rats, and its gene is strongly reduced in fat from people with obesity. R3 ⚪ No human treatment studies exist to date; human blood levels tend to be lower in type 2 diabetes and rise with regular exercise. R4, R5 Whether it could help people is an open question worth future study.
Biggest risks: unknown: human safety has never been studied.
Rating
| Human Human evidence | None for taking it; observational studies only R4, R5 |
| Animal Animal / lab evidence | Mice and rats with diet-induced obesity R3 |
| Regulatory | Not approved anywhere · not on FDA's 503A or 503B bulk-substance category lists and not on FDA's compounding safety-risk page R6, R7, R8 · not named on WADA's 2026 list; as a drug not approved anywhere for human use it falls under S0 (non-approved substances) R9 |
| Established human dose | No |
Evidence verdict: Weight loss: No human data (rodent studies only) · Diabetes or other uses: No human data (blood-level studies only)
This page reports what studies used. It is not dosing advice.
Legend: HUMAN data · ANIMAL / LAB data · UNKNOWN · UNVERIFIED: not yet confirmed against a primary source
About the evidence: rodent weight loss and human blood-level associations do not show that taking spexin works in people.
What is it?
Related pages: nesfatin-1, phoenixin, adropin.
Does it work?
- Animal Weight: in obese mice and rats, spexin reduced food intake and body weight and cut fat-cell fatty-acid uptake. R3
- ⚪ Type 2 diabetes: a meta-analysis of 11 studies found lower levels, with very high variation between studies. R4
- ⚪ Exercise: levels rise with regular exercise in a meta-analysis. R5
- ⚪ A systematic review covers obesity links across human, animal and cell studies. R10
- ⚪ CT.gov lists only observational studies (searched Oct 27, 2026).
Is it safe?
- ⚪ No human safety data.
Gray-market vials: extra risks
A gray-market vial has no quality control and no guarantee of identity, strength or sterility. We test retail vials blind under the Open Peptide Standard; see /tests/. A passing test covers one batch on one date and does not mean the compound is safe.
Is it legal?
- US: not FDA-approved; no Drugs@FDA application found (openFDA searched Oct 27, 2026).
- Compounding: not on FDA's 503A or 503B bulk-substance category lists and not on FDA's compounding safety-risk page. R6, R7, R8
- Sport: not named on WADA's 2026 list; as a drug not approved anywhere for human use it falls under S0 (non-approved substances) R9.
Study details
Study details
These are amounts researchers used, not recommendations.
| Study | People / model | Route | Amount used | Follow-up | Reported | Citation |
|---|---|---|---|---|---|---|
| No human dosing study | — | — | — | — | — | — |
| Walewski 2014 | Mice and rats with diet-induced obesity | Injection | Per protocol | Per protocol | Less food intake and weight | PMID 24550067 |
Full reference list (PubMed, CT.gov, FDA and WADA checked Oct 27, 2026)
- R1 Mirabeau O, et al. Genome Res. 2007. PMID 17284679
- R2 Sun X, et al. Peptides. 2023. PMID 36914115
- R3 Walewski JL, et al. Obesity (Silver Spring). 2014. PMID 24550067
- R4 Sun X, et al. Front Endocrinol (Lausanne). 2026. PMID 42039133
- R5 Aydemir İ, et al. Medicina (Kaunas). 2026. PMID 41597393
- R6 FDA, 503A bulk drug substances categories list (updated May 14, 2026). https://www.fda.gov/media/94155/download
- R7 FDA, 503B bulk drug substances categories list (updated Mar 21, 2025). https://www.fda.gov/media/94164/download
- R8 FDA, Certain bulk drug substances for use in compounding that may present significant safety risks (content current Apr 22, 2026). https://www.fda.gov/drugs/human-drug-compounding/certain-bulk-drug-substances-use-compounding-may-present-significant-safety-risks
- R9 WADA. The 2026 Prohibited List, S0 Non-approved substances; full list checked, compound not named. https://www.wada-ama.org/sites/default/files/2025-09/2026list_en_final_clean_september_2025.pdf
- R10 Behrooz M, et al. J Diabetes Metab Disord. 2020. PMID 33520870
Disclaimer
This page is for education and harm reduction, not medical advice or a recommendation to use Spexin (neuropeptide Q, NPQ). This is a naturally occurring peptide that has never been tested as a treatment in people and is not approved anywhere. Products sold under this name are unregulated research chemicals. Report problems to FDA MedWatch (https://www.fda.gov/safety/medwatch).