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Peptide library · Metabolic

Semaglutide

A synthetic GLP-1 receptor agonist peptide. Compounded semaglutide is not FDA-approved, while FDA-approved versions exist and have been studied in large controlled human trials.

Last reviewed September 22, 2026

The short version

Semaglutide is a lab-made version of the human signaling peptide GLP-1, altered so it remains in circulation longer. Its evidence base includes rodent mechanism studies and large randomized trials in people. Those trials concern FDA-approved products, not every compounded preparation sold under the generic name.

FDA-approved versions exist, but compounded semaglutide is not FDA-approved. A licensed provider decides whether a compounded preparation answers a documented need for a particular patient.

What it is

Semaglutide is a synthetic, 31-amino-acid analogue of glucagon-like peptide-1, or GLP-1. It shares about 94 percent of its sequence with human GLP-1. Two amino-acid changes slow enzymatic breakdown, while a fatty-acid side chain increases albumin binding. It is a GLP-1 receptor agonist, meaning it is shaped to activate the receptor used by the natural gut hormone.

The molecule was also researched under the codes NNC0113-0217 and NN9535. Its molecular formula is C187H291N45O59, molecular weight is 4,113.64 daltons and CAS number is 910463-68-2. A clinical reference monograph documents its GLP-1 similarity and long circulation time.1

Where the research stands

Semaglutide has substantial controlled human evidence across several defined patient populations. Mechanism work still matters: rodent studies help explain where the molecule signals, but they do not substitute for human outcomes or establish anything about the quality of a compounded product.

How far the evidence has climbed

  1. Cell studiesYesReceptor and cellular pharmacology
  2. Animal studiesYesBrain-pathway studies in mice and rats
  3. Small human pilotsYesEarly pharmacology and formulation studies
  4. Controlled human trialsYesLarge randomized outcome programs
  5. Compounded preparationNot approvedSeparate FDA-approved products exist

Here is what some of the most-cited studies looked at. Each names its species, because a result in a rat is not a result in a person.

  • MiceRats2020

    Brain signaling in rodents

    Researchers traced semaglutide access and signaling across brain regions in mice and rats and measured food intake, food preference and energy expenditure. It did not test people or a compounded preparation.2

  • Humans2016

    Cardiovascular trial in diabetes

    A randomized trial enrolled 3,297 adults with type 2 diabetes and high cardiovascular risk and measured cardiovascular events and diabetic-retinopathy complications. The study used an investigational semaglutide trial product; it did not test compounded semaglutide.3

  • Humans2021

    Weight-management trial

    A randomized trial followed 1,961 adults with overweight or obesity and no diabetes and measured body-weight change and adverse events against placebo. It did not test compounded semaglutide.4

  • Review2021

    Clinical safety review

    A review summarized gastrointestinal adverse effects, biliary events and unresolved pancreatic and thyroid questions across clinical evidence. It did not evaluate the quality of compounded preparations.5

  • Humans2023

    Cardiovascular outcomes without diabetes

    A placebo-controlled trial enrolled 17,604 adults with cardiovascular disease and overweight or obesity, but no diabetes, and measured major cardiovascular events. It did not test compounded semaglutide.6

  • Humans2024

    Kidney outcomes trial

    A randomized trial enrolled 3,533 adults with type 2 diabetes and chronic kidney disease and measured kidney and cardiovascular endpoints. It did not test compounded semaglutide.7

What the research can’t tell you

  • Trials do not validate compounded copies

    Results for an FDA-approved product cannot establish the identity, potency, stability or quality of a compounded preparation.

  • Gastrointestinal effects are common

    Nausea, vomiting, diarrhea and constipation dominate the clinical safety profile and account for many treatment discontinuations.5

  • Some risks depend on the population

    The trial reported a retinopathy signal in people with type 2 diabetes at high cardiovascular risk. It does not establish the same risk in every population.3

  • Rare and long-term outcomes remain hard

    Even large trials have limited power for uncommon harms, while rodent thyroid findings do not settle the human question. The safety review treats several signals as unresolved.5

Compounded semaglutide and FDA status

FDA-approved versions exist; compounded semaglutide is not FDA-approved

Approved semaglutide drug products exist. Compounded semaglutide does not carry that approval, and FDA does not verify a compounded drug’s safety, effectiveness or quality before marketing.8

FDA determined that the national shortage of semaglutide injection products ended on February 21, 2025.9 FDA says section 503A restricts compounding drugs that are essentially copies of commercially available products regularly or in inordinate amounts; section 503B has a separate framework.10

FDA also says semaglutide sodium and semaglutide acetate are different active ingredients from the one used in approved products.8 Promise Peptides is currently taking waitlist sign-ups. Joining is not a medical request and no prescription comes from it.

A prescription route

Promise is currently accepting waitlist signups. Joining is not a treatment request and does not result in a prescription. If treatment visits open, any treatment request would require clinical review; prescribing and pharmacy fulfillment would remain separate decisions.

  1. Start on Promise’s semaglutide page

    It shows what the treatment involves and its current availability.

  2. Answer the semaglutide questionnaire

    A licensed provider reviews health history, medicines and goals, and can decline. Not everyone qualifies.

  3. Pharmacy review is a separate step

    A prescription does not guarantee preparation or dispensing. A pharmacy must separately determine whether it can fulfill the prescription under the applicable requirements.

A prescription does not make compounded semaglutide FDA-approved or extend the approved-product trials to that preparation; it records an individualized clinical decision.

Semaglutide at Promise

Read the treatment information and view the current waitlist.

Join the Promise waitlist

Peak may earn money when readers become Promise patients.

Joining does not guarantee future treatment availability. Availability would depend on the treatment, state, clinical review and separate pharmacy review.

Questions

What is compounded semaglutide?

It is a preparation made by a compounding pharmacy for a patient rather than an FDA-approved finished drug made under an approved application. The compounded form is not FDA-approved.8

Is semaglutide a GLP-1?

It is a synthetic GLP-1 analogue and GLP-1 receptor agonist. It resembles the human hormone but includes changes that slow its removal from circulation.1

What are the main limits of the evidence?

The large trials answer defined questions about approved products in studied populations. They do not validate every compounded version, and uncommon or very long-term harms can remain uncertain.

Sources

  1. Kommu S, Whitfield P. Semaglutide. StatPearls. 2024 Jan. PubMed 38753931
  2. Gabery S, et al. Semaglutide lowers body weight in rodents via distributed neural pathways. JCI Insight. 2020. PubMed 32213703
  3. Marso SP, et al. Semaglutide and cardiovascular outcomes in patients with type 2 diabetes. N Engl J Med. 2016. PubMed 27633186
  4. Wilding JPH, et al. Once-weekly semaglutide in adults with overweight or obesity. N Engl J Med. 2021. PubMed 33567185
  5. Smits MM, Van Raalte DH. Safety of semaglutide. Front Endocrinol. 2021. PubMed 34305810
  6. Lincoff AM, et al. Semaglutide and cardiovascular outcomes in obesity without diabetes. N Engl J Med. 2023. PubMed 37952131
  7. Perkovic V, et al. Effects of semaglutide on chronic kidney disease in patients with type 2 diabetes. N Engl J Med. 2024. PubMed 38785209
  8. U.S. Food and Drug Administration. FDA’s concerns with unapproved GLP-1 drugs used for weight loss. Content current as of September 1, 2026.
  9. U.S. Food and Drug Administration. Declaratory Order: Resolution of Shortages of Semaglutide Injection Products. February 21, 2025.
  10. U.S. Food and Drug Administration. Compounding when drugs are on FDA’s drug shortages list.