What Does Research Report About Too Much Retatrutide?
What trial arms, drug labels and poison centre reports record after excess GLP-1 dosing, and why retatrutide has no approved label to cite.
Research use only. This page is scientific background and community-report context. Every compound sold here is supplied strictly for in-vitro research. Nothing on the page is a protocol, a recommendation, or medical advice.
TL;DR: the published record after too much retatrutide
Research question: What does the published record report after too much retatrutide?
What the published data say: The phase 2 obesity trial studied once-weekly subcutaneous retatrutide over 48 weeks (PMID 37366315, NCT04881760). Its highest arm was 12 mg once weekly (n=62 in the 12 mg arm) versus placebo, and the paper reports the adverse events of its 1 mg to 12 mg arms as dose-related and mostly mild to moderate (PMID 37366315, NCT04881760).
What has not been studied: PubMed esearch on 2026-09-17 for retatrutide overdose returned 0 hits; retatrutide AND (overdose OR poisoning OR toxicity) returned 1 hit (PMID 41303824), not an overdose report. No approved prescribing information exists for retatrutide, hence no Overdosage section for it.
What research communities report: in the Reddit corpus we track, 219 question posts in 12 months matched the overdose and GLP-1 patterns, 2 of them in the 13 to 17 Sept 2026 window (base 87,002 and 956 posts). These are reports, not evidence.
What is the highest retatrutide dose in the published trials?
The highest randomised retatrutide dose in the phase 2 obesity trial is 12 mg once weekly, given subcutaneously for 48 weeks versus placebo (12 mg arm: n=62; PMID 37366315, NCT04881760). These are the study arms of the cited trials, not an application protocol for research vials.
NCT04881760 records that 12 mg arm as a "2 mg LY3437943 starting dose followed by 4 mg LY3437943, 8 mg LY3437943 and then 12 mg LY3437943 administered as SC injection QW". The same protocol assigned 1 mg, 4 mg or 8 mg LY3437943, or placebo, on that weekly schedule.
The phase 1b paper reported a retatrutide half-life of approximately 6 days (PMID 36354040).
No approved prescribing information exists for retatrutide, hence no Overdosage section for it: Drugs@FDA openfda.generic_name:"retatrutide" returned 0, NOT_FOUND on 2026-09-17, and of the 10 DailyMed SPL entries the two checked carry no overdose text.
What adverse events did the trials report by dose group?
The phase 2 obesity trial studied once-weekly subcutaneous retatrutide over 48 weeks (PMID 37366315, NCT04881760). Across the 1 mg to 12 mg arms and placebo, the phase 2 paper states that "these events were dose-related, were mostly mild to moderate in severity" (PMID 37366315). NCT04881760 otherEvents counts nausea and vomiting to 52 weeks.
- Nausea n/N
- 8/70
- Vomiting n/N
- 1/70
- Comparator
- none (control)
- Nausea n/N
- 10/69
- Vomiting n/N
- 2/69
- Comparator
- placebo
- Nausea n/N
- 21/35
- Vomiting n/N
- 9/35
- Comparator
- placebo
- Nausea n/N
- 28/62
- Vomiting n/N
- 12/62
- Comparator
- placebo
NCT04881760 seriousEvents lists one acute pancreatitis in the 12 mg group and none on placebo: "Pancreatitis acute EG000 0/70 ; EG006 1/62" (to 52 weeks).
A published case report concerning an online-purchased product marketed as retatrutide describes a confounded presentation: in one patient with type 1 diabetes and a concurrent Shigella infection the paper describes "severe vomiting, diarrhoea, hyperglycaemia, ketonaemia and acute kidney injury shortly after self-administering an online-purchased product marketed as retatrutide" and states "While causation cannot be established" (PMID 42669023). That is a single case report, not a rate.
What do approved GLP-1 labels say about overdose?
Approved Overdosage sections exist for semaglutide and tirzepatide, not for retatrutide. PeptidesDirect does not sell semaglutide. PeptidesDirect does not sell tirzepatide.
The EMA Ozempic SmPC section 4.9 states: "There is no specific antidote for overdose with semaglutide." The same section records: "Overdoses of up to 4 mg in a single dose, and up to 4 mg in a week have been reported in clinical trials." The US OZEMPIC prescribing information section 10 (setid adec4fd2-6858-4c99-91d4-531f5f2a2d79, June 10 2026) keys observation to "taking into account the long half-life of OZEMPIC of approximately 1 week". PeptidesDirect does not sell semaglutide.
The EMA Mounjaro SmPC section 4.9 states: "There is no specific antidote for overdose of tirzepatide." The US MOUNJARO and ZEPBOUND prescribing information sections 10 (setids d2d7da5d-ad07-4228-955f-cf7e355c8cc0 and 487cd7e7-434c-4925-99fa-aa80b1cc776b, both September 02 2026) include "consider contacting the Poison Help line (1-800-222-1222) or a medical toxicologist" and "taking into account the half-life of tirzepatide of approximately 5 days". PeptidesDirect does not sell tirzepatide. This page gives one pointer only: emergency services and the national poison centre.
What do poison centre reports describe after dosing errors?
No poison centre series of retatrutide overdose is published as of 2026-09-17. Published GLP-1 class registry counts are not a prognosis and not a retatrutide incidence.
Senthilkumar 2026 summarized 13,924 GLP-1 exposures in the USA from 2017 to 2024 (PMID 41784916, NPDS): "Most exposures (91.7%) were associated with no or mild effects ... major effects occurred in 42 exposures; there were two deaths."
Muschler 2025 reviewed 237 cases at one US centre from 2014 to 2023 (PMID 39803696): "Most calls (n = 164, 69.2%) were due to unintentional therapeutic errors." "Hypoglycemia was identified in eight patients (3.4%)."
Marshall 2024 reviewed 152 charts at one US centre from 2006 to 2023 (PMID 38861153): "Therapeutic errors accounted for 91% of exposures. Most patients (67%) reported no symptoms"; "21% ... errors on initial use of the pen".
Gartner 2025 reviewed 152 patients at three US centres from 2005 to 2023 (PMID 40269635): "Nausea (92%) and vomiting (76%) were the most reported clinical effects in the symptomatic group. Hypoglycemia occurred in 9% of patients." Those effects "lasted 8 to 24 hours".
Poison centre reports and the FDA compounding alert current on 07/26/2024 describe confusion between milligrams and milliliters drawn from multiple-dose compounded vials, with patients administered five to 20 times more than the intended dose of semaglutide. Lambson 2023 described three compounded-vial cases, two of them tenfold dosing errors, in which "All patients experienced notable symptoms of nausea, vomiting, and abdominal pain" (PMID 37392810). Wiener 2024 reported three unintentional subcutaneous semaglutide initiation errors (PMID 38470137): 2 mg in place of 0.1 mg, 2.4 mg in place of 0.25 mg, and 1.7 mg, with nonspecific gastrointestinal symptoms and no hypoglycemia. Both are case reports, not a rate. PeptidesDirect does not sell semaglutide.
Products mentioned
Retatrutide (LY3437943) is a synthetic 39-amino-acid peptide that acts on three receptors at once: GLP-1, GIP and glucagon. Supplied as a lyophilized powder for in-vitro research, with a batch-specific third-party certificate of analysis.
Sources
- PMID 37366315; NCT04881760. Highest randomised retatrutide dose, phase 2 obesity, 12 mg once weekly subcutaneous, 48 weeks.
- Urva 2022. Once-weekly subcutaneous LY3437943, phase 1b, 12 weeks. PMID 36354040, NCT04143802.
- European Medicines Agency. Ozempic SmPC section 4.9.
- European Medicines Agency. Mounjaro SmPC section 4.9.
- U.S. FDA / DailyMed. OZEMPIC prescribing information section 10, setid adec4fd2-6858-4c99-91d4-531f5f2a2d79, June 10 2026.
- U.S. FDA / DailyMed. MOUNJARO prescribing information section 10, setid d2d7da5d-ad07-4228-955f-cf7e355c8cc0, September 02 2026.
- U.S. FDA / DailyMed. ZEPBOUND prescribing information section 10, setid 487cd7e7-434c-4925-99fa-aa80b1cc776b, September 02 2026.
- Senthilkumar 2026. National Poison Data System GLP-1 exposures, USA, 2017 to 2024. PMID 41784916.
- Muschler 2025. 237 cases, one US centre, 2014 to 2023. PMID 39803696.
- Marshall 2024. 152 charts, one US centre, 2006 to 2023. PMID 38861153.
- Gartner 2025. 152 patients, 3 US centres, 2005 to 2023. PMID 40269635.
- Wiener 2024. Unintentional semaglutide overdoses at initiation, 3 cases. PMID 38470137.
- Lambson 2023. Tenfold errors from compounded vials, 3 cases. PMID 37392810.
- Branine 2026. Online-purchased product marketed as retatrutide, 1 patient. PMID 42669023.
- U.S. FDA. Compounding alert, current 07/26/2024.
- PMID 41303824. Review of gastrointestinal effects of anti-obesity medicines (PubMed hit for retatrutide AND overdose OR poisoning OR toxicity; not an overdose report).
Research use only. Retatrutide is supplied for laboratory research, not for human or animal administration, and not as a medicine. Nothing in this article is a protocol, a recommendation, or medical advice.
Research context for English-speaking buyers
Most of our English-speaking customers ship to the UK, Ireland, Malta or other English-as-second-language EU territories. The regulatory picture differs per country.
- Relevant authorities
- MHRA (UK, post-Brexit), HPRA (Ireland, EU-aligned), FDA Section 503A bulks list (US, restricted Cat 2 status of several peptides as of 2026)
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- Typical shipping window
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Research-grade peptides shipped from our EU warehouse are sold for laboratory use only and are not authorised for human or veterinary therapeutic application in any of the destination jurisdictions. US customers should be aware that the FDA Section 503A bulks list classification (and the April 2026 reclassification of twelve compounds) only governs compounding pharmacies, not direct-to-researcher imports for non-clinical work. UK buyers should declare the consignment on import and may be asked for a research justification by HMRC. We provide a CoA per batch identified by colour code rather than serial number; customs sometimes asks for this document when clearing the parcel.