Evidence review: Open Peptide Project (verified against primary PubMed, ClinicalTrials.gov & FDA records) · Last checked 2026-10-27. ← Back to Evidence Library · Trial & Regulatory Tracker →

Avexitide (exendin 9-39): what the evidence says

Name: Avexitide (exendin 9-39)
Published: 2026-10-27

At a glance

What it is: a peptide fragment (amino acids 9 to 39 of exendin-4) that blocks the GLP-1 receptor, the opposite of drugs like semaglutide. ^R1 Developed first by Eiger and now by Amylyx for dangerous low blood sugar after gastric bypass surgery. ^{R2, R3}

What the evidence says: Human small placebo-controlled studies cut low-blood-sugar episodes after gastric bypass, ^R4 and Amylyx reports that its 78-person phase 3 cut serious episodes by 55% vs placebo. That phase 3 result is not yet peer-reviewed. ^R3

Biggest risks: injection-site reactions and diarrhea were most common in the phase 3; no treatment-related serious side effects were reported. ^R3

Rating


Human Human evidence	Limited: one small crossover RCT (n = 18) and an uncontrolled phase 2, plus a company-reported phase 3 (n = 78) ^{R4, R5, R3}
Animal Animal / lab evidence	Not reviewed
Regulatory	Investigational · not FDA-approved · 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 (trial amounts only; see Study details)

Evidence verdict: Low blood sugar after gastric bypass: Limited (small RCTs published; one positive phase 3 reported by the company) · Congenital hyperinsulinism: Very limited (small crossover studies) · Other uses: No human data

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: the published trials are small (under 30 people each). The phase 3 is larger and placebo-controlled but has only been reported by the company. The page will need an update once it is published and the FDA reviews it.

What is it?

Related pages: exenatide, glucagon, dasiglucagon.

Does it work?

Human Early studies: blocking GLP-1 with intravenous and then injected exendin 9-39 prevented low blood sugar after a glucose drink in small groups of women after gastric bypass (8 and 9 people). ^{R10, R11, R12}
Human PREVENT (phase 2 crossover, n = 18): vs placebo, two regimens raised the lowest blood sugar by 21% and 26% and cut the insulin peak by 23% and 21%. ^{R4, R2}
🟨 Phase 2 (n = 25 enrolled, compared with baseline, no placebo): Level 2 low-sugar events on continuous monitors fell 48% to 59%, and severe (Level 3) events fell about 67%. ^{R5, R13}
Human LUCIDITY (phase 3, 16 weeks, n = 78): combined Level 2 and 3 events fell 55% vs placebo (rate ratio 0.45); all secondary goals met. Company-reported, not peer-reviewed. ^{R3, R14}
Human Congenital hyperinsulinism: in small crossover studies (9 and 16 children or adults), it raised fasting blood sugar. ^{R15, R16, R17}

Is it safe?

Human LUCIDITY: no treatment-related serious side effects; most common were diarrhea and injection-site redness or bruising (company-reported). ^R3
Human Small studies reported it as generally well tolerated. ^{R4, R12}
Long-term safety unknown.

Pipeline status (investigational)

Sponsor: Amylyx Pharmaceuticals (earlier Eiger BioPharmaceuticals). ^{R3, R2}
Trials: LUCIDITY phase 3, positive topline Aug 2026 ^{R14, R3}; expanded access available. ^R18
Expected: company plans an FDA filing by the end of 2026; it holds Breakthrough Therapy and Orphan Drug designations (company-reported). ^R3

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

These are amounts researchers used, not recommendations.

Study	People / model	Route	Amount used	Follow-up	Reported	Citation
PREVENT (phase 2 crossover)	18 women after gastric bypass	Subcutaneous	30 mg twice daily or 60 mg once daily	Per protocol (crossover with placebo)	Glucose nadir +21% and +26%	PMID 33616643
Phase 2 (NCT04652479)	25 enrolled	Subcutaneous	45 mg twice daily or 90 mg once daily	Per protocol, vs baseline	Level 2 events −48% to −59%	PMID 42744082
LUCIDITY (phase 3)	78 adults after gastric bypass	Subcutaneous	90 mg once daily	16 weeks	Level 2/3 events −55% vs placebo (company-reported)	^R3
Stefanovski 2022 (congenital hyperinsulinism)	16 children	Intravenous	0.28 to 0.6 mg/kg	Open-label crossover	Higher fasting glucose	PMID 35416981

Full reference list (PubMed, CT.gov, FDA and WADA checked Oct 27, 2026)

^R1 Ng CM, et al. Br J Clin Pharmacol. 2018. PMID 29077992
^R2 ClinicalTrials.gov NCT03373435, PREVENT, phase 2 crossover in post-bariatric hypoglycemia, Eiger, completed, 18 enrolled (CT.gov API v2, checked Oct 27, 2026). https://clinicaltrials.gov/study/NCT03373435
^R3 Amylyx Pharmaceuticals, LUCIDITY phase 3 topline results for avexitide (press release, SEC Form 8-K exhibit 99.1), Aug 18, 2026. https://www.sec.gov/Archives/edgar/data/1658551/000119312526354716/d180533dex991.htm
^R4 Craig CM, et al. J Clin Endocrinol Metab. 2021. PMID 33616643
^R5 Craig C, et al. Metabolism. 2026. PMID 42744082
^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 Craig CM, et al. Diabetologia. 2017. PMID 27975209
^R11 Craig CM, et al. Diabetes Obes Metab. 2018. PMID 28776922
^R12 Tan M, et al. Diabetes Obes Metab. 2020. PMID 32250530
^R13 ClinicalTrials.gov NCT04652479, phase 2 in post-bariatric hypoglycemia, completed, 25 enrolled (CT.gov API v2, checked Oct 27, 2026). https://clinicaltrials.gov/study/NCT04652479
^R14 ClinicalTrials.gov NCT06747468, LUCIDITY, phase 3 in post-bariatric hypoglycemia, Amylyx, active not recruiting (CT.gov API v2, checked Oct 27, 2026). https://clinicaltrials.gov/study/NCT06747468
^R15 Calabria AC, et al. Diabetes. 2012. PMID 22855730
^R16 Stefanovski D, et al. Diabetes Care. 2022. PMID 35416981
^R17 ClinicalTrials.gov NCT00571324, phase 1/2 crossover in congenital hyperinsulinism, completed, 9 enrolled (CT.gov API v2, checked Oct 27, 2026). https://clinicaltrials.gov/study/NCT00571324
^R18 ClinicalTrials.gov NCT07582874, expanded access for post-bariatric hypoglycemia, available (CT.gov API v2, checked Oct 27, 2026). https://clinicaltrials.gov/study/NCT07582874

Disclaimer

This page is for education and harm reduction, not medical advice or a recommendation to use Avexitide (exendin 9-39). This is an investigational drug. It is available only inside registered clinical trials; products sold online under this name are unregulated. Report problems to FDA MedWatch (https://www.fda.gov/safety/medwatch).