Semaglutide is a GLP-1 receptor agonist from Novo Nordisk, FDA-approved as Ozempic and Rybelsus for type 2 diabetes and as Wegovy for weight management, cardiovascular risk reduction and a form of fatty liver disease. Vials sold online as "research" semaglutide are not those drugs. They have no approval behind them, and FDA has warned the companies that sell them.
Notice: Research peptides are sold for in-vitro laboratory research only. Research-labeled vials are not the approved drug, not for human or animal consumption, and this page is not medical advice. It contains no dosing or use guidance.
How semaglutide works
Semaglutide "mimics a hormone called glucagon-like peptide-1 (GLP-1) that targets areas of the brain that regulate appetite and food intake," according to FDA's Wegovy announcement. It's a modified peptide with a fatty side chain that lets it bind to albumin in the blood, which is why the injection is given once a week.
It acts on one receptor. Tirzepatide adds a second (GIP), and the investigational retatrutide a third (glucagon). The head-to-head data is in semaglutide vs tirzepatide.
Approvals
| Date | Product | What FDA approved | Source |
|---|---|---|---|
| December 5, 2017 | Ozempic | Type 2 diabetes in adults | Drugs.com history |
| September 20, 2019 | Rybelsus | First oral GLP-1 for type 2 diabetes | FDA |
| January 16, 2020 | Ozempic | Cardiovascular risk reduction in type 2 diabetes with heart disease | Drugs.com |
| June 4, 2021 | Wegovy | Chronic weight management in adults | FDA |
| December 23, 2022 | Wegovy | Obesity in teens 12 and older | Drugs.com |
| March 8, 2024 | Wegovy | Cardiovascular risk reduction in overweight or obesity with heart disease | Drugs.com |
| January 28, 2025 | Ozempic | Kidney disease worsening and cardiovascular death in type 2 diabetes with chronic kidney disease | Drugs.com |
| August 15, 2025 | Wegovy | MASH (accelerated approval) | Drugs.com |
| December 22, 2025 | Wegovy pill | First oral GLP-1 for weight loss | Drugs.com |
| March 19, 2026 | Wegovy HD | Higher-strength weekly injection (accelerated approval) | Novo Nordisk |
What the trials found
Novo Nordisk's main weight-management program is called STEP. Its cardiovascular outcomes trial in people without diabetes is SELECT. The figures below describe the approved drug in controlled trials, not any individual result.
STEP 1 (obesity, no diabetes)
1,961 adults, 68 weeks. Mean weight change was -14.9% on semaglutide versus -2.4% on placebo. 4.5% on semaglutide stopped because of gastrointestinal events, versus 0.8% on placebo (ACC summary; NEJM).
SELECT (cardiovascular outcomes)
17,604 adults with overweight or obesity and established cardiovascular disease, none with diabetes, followed for a mean of 40 months. Results, per the American College of Cardiology summary:
| Outcome | Semaglutide | Placebo |
|---|---|---|
| Cardiovascular death, heart attack or stroke | 6.5% | 8.0% |
| Hazard ratio | 0.80 (95% CI 0.72-0.90) | |
| Weight change at 104 weeks | -9.4% | -0.9% |
| Stopped due to adverse events | 16.6% | 8.2% |
This trial was the basis for Wegovy's March 2024 cardiovascular indication.
STEP UP (Wegovy HD)
A 72-week phase 3 program. Novo Nordisk reported 20.7% mean weight loss on the efficacy estimand and 18.7% on the treatment-regimen estimand, which counts everyone regardless of adherence (Novo Nordisk, March 19, 2026).
Side effects
FDA lists nausea, diarrhea, vomiting, constipation and abdominal pain among Wegovy's most common side effects. Semaglutide products carry a boxed warning about thyroid C-cell tumors seen in rodents (FDA). The prescribing information is the authoritative source.
Shortage, compounding and research labels (October 2026)
- Shortage over. FDA said on February 21, 2025 that the semaglutide injection shortage was resolved. Enforcement discretion for 503B outsourcing facilities ended May 22, 2025, and FDA says the period for state-licensed pharmacies "has ended" (FDA, content current as of April 1, 2026).
- February 2026 crackdown. On February 6, 2026, FDA said it would restrict GLP-1 ingredients used in mass-marketed non-approved compounded drugs and act against misleading marketing of them (FDA).
- 503B proposal. On April 30, 2026, FDA proposed excluding semaglutide, tirzepatide and liraglutide from the 503B bulks list (Federal Register). We found no final decision as of October 21, 2026.
- Salt forms. FDA says semaglutide sodium and semaglutide acetate "are different active ingredients than are used in the approved drugs" (FDA, current as of October 1, 2026).
- Adverse events. As of May 31, 2026, FDA had received 990 adverse event reports for compounded semaglutide, which it says are likely underreported (same page).
- "Research" labels. FDA says it has warned companies selling semaglutide "falsely labeled 'for research purposes' or 'not for human consumption.'" Its August 24, 2026 letter to Peptide Partners named a product sold as "GLP-1 S (Semaglutide)."
More: FDA peptide regulation in 2026 and our regulatory news log.
Research-grade vials: what the market looks like
On October 21, 2026, 37 vendors in our price index had semaglutide in stock, at a median of $8.25 per mg. Code names are common. The cheapest per mg were:
| Vendor | Listing | Price | $/mg |
|---|---|---|---|
| True Research Labs | Semaglutide (listed as GLP-1-SM) 30mg | $84.00 | $2.80 |
| Elite Research USA | GLP(1)Sg Research Peptide 20mg | $59.99 | $3.00 |
| Maximum Peptides | Semaglutide 20mg | $79.00 | $3.95 |
Prices are as listed on vendors' sites on October 21, 2026, and they change often. See the semaglutide price page for every listing and best semaglutide vendors for our certificate comparison.
None of the STEP or SELECT data applies to these vials. They aren't Novo Nordisk's product, and nobody outside the seller and its lab checks what's in them.
How to check a semaglutide COA
- The certificate names semaglutide, not just "GLP-1" or a code.
- Identity by mass spectrometry. Semaglutide's molecular weight is about 4,114 g/mol.
- The salt form is stated. FDA treats sodium and acetate salts as different active ingredients, and the salt changes how much peptide a labeled milligram contains (TFA vs acetate salts).
- Measured content against the label (purity vs net content).
- A lot number matching your vial, a recent date and a named lab you can verify.
Our COA guide and COA checklist explain each check.
Bottom line
Semaglutide is one of the most studied drugs in its class, approved in injectable and oral forms with diabetes, weight, cardiovascular, kidney and liver indications. The shortage that allowed widespread compounding ended in February 2025, and FDA tightened rules further in 2026. Research-labeled semaglutide isn't any of the approved products, and FDA has named it in warning letters.
Sources are linked inline and were checked October 21, 2026. We'll update this page when FDA finalizes its 503B decision or approves new semaglutide products.
