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Nesfatin-1

Also called Nesfatin, NUCB2-derived nesfatin-1, Nucleobindin-2 (1-82) fragment, NEFA/nucleobindin-2 N-terminal fragment, Nesfatin-1 (human), Nesfatin-1 (rat)

Nesfatin-1 is a natural peptide cut from a larger protein called NUCB2. Injected into the brains of rats, it made them eat less, which is why it is sold online as an appetite or weight-loss peptide. It has never been given to people in any published study; human research only measures how much of it is in the blood.

UnverifiedSold online, but not an approved drug and with no published human trials. What it really contains is not verified.

New · under editorial review. Added October 31, 2026 by our automated research, with every claim sourced. A person has not checked this page yet; treat it with extra care. How we research

Illustrative chain. The exact sequence has not been published in a source we could verify.

Overview

Nesfatin-1 is a natural peptide cut from a larger protein called NUCB2. Injected into the brains of rats, it made them eat less, which is why it is sold online as an appetite or weight-loss peptide. It has never been given to people in any published study; human research only measures how much of it is in the blood.

How it works

Shown in animals: injected into the brain of rats, nesfatin-1 cut food intake and body weight, and this did not depend on leptin 3. It works at least partly through brain melanocortin and oxytocin pathways 5. Given by injection into the belly cavity of mice, its middle segment reduced feeding through the brainstem 4. In mouse and rat islet studies it boosted insulin release only when glucose was high 67. Its receptor is still unknown; a 2021 systematic review found growing but indirect evidence that it acts through a G protein-coupled receptor 2. Whether it does any of this when injected in people is unknown.

What research shows

  • Discovery study (2006, rats): brain injections of nesfatin-1 reduced eating in a dose-dependent way; long-term injections reduced body weight, and blocking it increased appetite 3.
  • Mouse study (2009): injection into the belly cavity reduced food intake, including in leptin-resistant obese mice; the active part was the middle segment 4.
  • Rat and cell studies (2011): continuous delivery by an implanted osmotic minipump lowered food intake and raised whole-body fat burning in rats; nesfatin-1 raised insulin release from islets only at high glucose 67.
  • Rat studies of other effects: brain injections raised blood pressure (2009) 12 and increased anxiety- and fear-like behavior (2008) 13.
  • Human observational study (2010, 43 lean men plus 9 men with high BMI): blood levels were lower with higher BMI and body fat, and did not change after a meal or sugar drink 8.
  • Human meta-analyses (blood levels only): 8 studies (305 people with type 2 diabetes, 205 controls) found levels differed, with very high variation between studies 9; 7 studies (237 patients) found no clear change after weight-loss surgery 10. Similar reviews exist for polycystic ovary syndrome 11.
  • No human administration studies: none found in PubMed, and no registered trials on ClinicalTrials.gov (searched 2026-10-31) 14.

What is claimed online

These are claims made where it is sold or discussed. They are not established facts, and some are contradicted by the evidence above.

  • Claimed: it suppresses appetite and causes weight loss in people. Evidence: it reduced eating and weight in rats and mice 346; it has never been tested in humans 14.
  • Claimed: it is a natural alternative to GLP-1 drugs. Evidence: it raised insulin release at high glucose in animal islets 67, but no human study has compared it with, or tested it like, GLP-1 drugs.
  • Claimed: low nesfatin-1 causes obesity, so topping it up helps. Evidence: human studies only show associations between blood levels and body weight or diabetes, with inconsistent results 8910.
  • Claimed: it calms anxiety or stress. Evidence: in rats, brain injections increased anxiety- and fear-like behavior 13.
  • Claimed: it is safe because the body makes it. Evidence: in rats it raised blood pressure 12; no human safety data exist.

Doses studied in people

No published human dosing data exist for nesfatin-1; doses circulating online are not from human trials and are extrapolated from rodent injections.

Read this first: these are the amounts given to participants in published studies or written on official prescribing labels, reported for reference. They are not recommendations. Trial doses were chosen for specific patients under medical supervision, and a dose that is safe in one person can be harmful in another.

Safety

  • No human safety data; it has never been given to people in a published study 14.
  • In rats, brain injections raised blood pressure through the sympathetic nervous system 12 and increased anxiety- and fear-like behavior 13. Whether injected doses reach the brain in people is unknown.
  • It changes insulin release in animal islets 67; effects on blood sugar in people, including those taking diabetes drugs, are untested.
  • Unknown long-term safety.
  • Products sold online as 'research peptides' are unregulated, so identity, purity, dose and contamination are not checked; rat and human sequences differ, and labels may not say which. FDA has warned companies that illegally sold unapproved drugs falsely labelled 'for research purposes' or 'not for human consumption' while supplying them to consumers for human use 15. FDA has also warned that compounded peptides can carry a risk of immune reactions from aggregation and peptide-related impurities (stated for peptides such as GHRP-2) 16.

Report side effects of any drug or product to the FDA through MedWatch. For a possible poisoning in the US, call Poison Control at 1-800-222-1222.

History

Oh-I and colleagues reported nesfatin-1 in Nature in 2006 as a new 'satiety molecule' in the rat hypothalamus 3. A related group showed effects after peripheral injection in mice in 2009 4 and set up a human blood test in 2010 8. Since then many human studies have measured blood levels in obesity, diabetes, polycystic ovary syndrome, depression and other conditions 91011, but none has given nesfatin-1 to people.

Common questions

Has nesfatin-1 been tested in humans?

No one has published a study giving nesfatin-1 to people. Human research only measures its blood levels in conditions such as obesity and diabetes 8914.

Does nesfatin-1 cause weight loss?

In rats and mice it reduced eating and body weight 34. Whether it does anything in people is unknown.

What are the known risks?

There are no human data. In rats, brain injections raised blood pressure and increased anxiety-like behavior 1213.

Is nesfatin-1 banned in sport?

It is not named on WADA's 2026 list, but as an unapproved substance it appears to fall under S0, banned at all times 20.

Related compounds

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Oxytocin

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Peptide YY (PYY 3-36)

PYY3-36 · PYY(3-36)

Peptide YY 3-36 (PYY 3-36) is a natural hormone that the gut releases after a meal and that helps signal fullness.

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Ghrelin

lenomorelin · acyl ghrelin

Ghrelin is a natural hormone made mostly in the stomach.

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Semaglutide

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Semaglutide is a long-acting copy of the gut hormone GLP-1.

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Setmelanotide

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Setmelanotide is a small ring-shaped peptide that turns on the brain's MC4 'fullness' receptor.

Sources

  1. UniProt P80303: Nucleobindin-2 (NUCB2), human; chain Nesfatin-1 (25-106) Regulatory
  2. Rupp SK et al. Nesfatin-1 receptor: distribution, signaling and increasing evidence for a G protein-coupled receptor - a systematic review. Front Endocrinol 2021 (PMID 34566899) PubMed review
  3. Oh-I S et al. Identification of nesfatin-1 as a satiety molecule in the hypothalamus. Nature 2006 (PMID 17036007) Journal
  4. Shimizu H et al. Peripheral administration of nesfatin-1 reduces food intake in mice: the leptin-independent mechanism. Endocrinology 2009 (PMID 19176321) Journal
  5. Nesfatin-1-regulated oxytocinergic signaling in the paraventricular nucleus causes anorexia through a leptin-independent melanocortin pathway. Cell Metab 2009 (PMID 19883614) Journal
  6. Gonzalez R et al. Nutrient responsive nesfatin-1 regulates energy balance and induces glucose-stimulated insulin secretion in rats. Endocrinology 2011 (PMID 21828181) Journal
  7. Gonzalez R et al. Nesfatin-1 exerts a direct, glucose-dependent insulinotropic action on mouse islet beta- and MIN6 cells. J Endocrinol 2011 (PMID 21224288) Journal
  8. Tsuchiya T et al. Fasting concentrations of nesfatin-1 are negatively correlated with body mass index in non-obese males. Clin Endocrinol 2010 (PMID 20550530) Journal
  9. A meta-analysis about the relationship of serum nesfatin-1 levels in patients with type 2 diabetes mellitus. Biomedica 2025 (PMID 40865110) PubMed review
  10. Bidares et al. The influence of bariatric surgery on serum level of nesfatin-1: a systematic review and meta-analysis. Health Sci Rep 2026 (PMID 41623366) PubMed review
  11. Blood nesfatin-1 levels in patients with polycystic ovary syndrome: a systematic review and meta-analysis. Front Endocrinol 2023 (PMID 38327900) PubMed review
  12. Yosten GL, Samson WK. Nesfatin-1 exerts cardiovascular actions in brain: possible interaction with the central melanocortin system. Am J Physiol Regul Integr Comp Physiol 2009 (PMID 19474390) Journal
  13. Merali Z et al. Nesfatin-1 increases anxiety- and fear-related behaviors in the rat. Psychopharmacology 2008 (PMID 18670764) Journal
  14. ClinicalTrials.gov search: intervention 'nesfatin' (no studies found, checked 2026-10-31) ClinicalTrials.gov
  15. FDA: FDA's Concerns with Unapproved GLP-1 Drugs Used for Weight Loss (content current as of 10/01/2026) Regulatory
  16. FDA: Certain bulk drug substances for use in compounding that may present significant safety risks (content current as of 04/22/2026) Regulatory
  17. FDA: Bulk drug substances nominated for use in compounding under section 503A (updated May 14, 2026) Regulatory
  18. Federal Register (public inspection): HHS notice, Enforcement Discretion Policy Regarding 503A Compounding Using Certain Peptide Bulk Drug Substances (Oct 2026) Regulatory
  19. AJMC: HHS Draft Policy Eases Enforcement on 6 Compounded Peptides (Oct 2026) Regulatory
  20. WADA 2026 Prohibited List (full text, Asia Rugby copy), section S0 Non-approved substances Regulatory

Last reviewed 2026-10-31 · How we research · Found an error? See our corrections policy.