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The phrase weight loss injections covers very different products. Only a few are FDA-approved for long-term weight management: Wegovy (semaglutide) and Zepbound (tirzepatide), both used once a week, and Saxenda and its generic liraglutide, used once a day. Imcivree (setmelanotide) is approved only for certain rare causes of obesity. Ozempic, Mounjaro and Trulicity are approved for type 2 diabetes, not weight loss. Compounded copies, “research” peptide vials, lipotropic and B12 shots, and HCG are not FDA-approved for weight loss at all.
Peptide Labs does not sell any prescription drug or injection. This article is general information, not medical advice. Whether any weight-loss medicine suits a person is a decision for a licensed prescriber.
Key Takeaways
- FDA-approved weight loss shots: Wegovy (2021), Zepbound (2023), Saxenda (2014) and generic liraglutide (2025).
- Imcivree is approved only for specific genetic conditions and, since March 2026, acquired hypothalamic obesity.
- Ozempic, Mounjaro and Trulicity are diabetes medicines; using them for weight is off-label.
- Compounded and "research use" GLP-1 products are not FDA-approved, and the FDA has logged hundreds of adverse event reports.
- Lipotropic, B12 and HCG shots have no FDA approval for weight loss and no good evidence that they cause it.
- The approved shots carry real warnings, including a boxed warning about thyroid tumors seen in rodents.
What counts as a weight loss injection?
Clinics, med spas and websites use the term for anything given as a shot and linked to weight. The table sorts the main types by what the FDA has actually approved and how strong the evidence is.
| Injection type | Examples | FDA status for weight | Evidence level |
|---|---|---|---|
| GLP-1 based medicines approved for weight | Wegovy, Zepbound, Saxenda, generic liraglutide | Approved for long-term weight management | Large randomized placebo-controlled trials |
| Rare-disease medicine | Imcivree (setmelanotide) | Approved only for specific genetic conditions and acquired hypothalamic obesity | Smaller trials in those groups |
| Diabetes GLP-1 medicines | Ozempic, Mounjaro, Trulicity, Victoza | Approved for type 2 diabetes, not weight management | Weight change reported in diabetes trials |
| Compounded GLP-1 copies | Compounded semaglutide or tirzepatide | Not FDA-approved; not reviewed by the FDA | No approval trials of the compounded product |
| "Research use" peptide vials | Semaglutide, tirzepatide, retatrutide sold online | Unapproved; the FDA calls these sales illegal | Contents untested; retatrutide still in trials |
| Lipotropic, MIC and B12 shots | Methionine, inositol, choline, vitamin B12 | Not approved for weight loss | No randomized trials in people found |
| HCG | Human chorionic gonadotropin | Prescription drug for infertility; not approved for weight loss | Label: no substantial evidence beyond calorie restriction |
FDA-approved weight loss shots
Four injectable brands, plus generic liraglutide, are approved for chronic weight management. Each is approved for use alongside a reduced-calorie diet and more physical activity, and the labels raise the amount gradually over several weeks to limit stomach side effects.
- Wegovy (semaglutide, Novo Nordisk): approved June 4, 2021; once weekly; adults and teens 12 and older with obesity, and adults with overweight plus a weight-related condition. It is also approved to lower the risk of heart attack and stroke in adults with heart disease and excess weight, and for a type of fatty liver disease (MASH).
- Zepbound (tirzepatide, Eli Lilly): approved November 8, 2023; once weekly; adults with obesity, or overweight plus a related condition, and moderate to severe obstructive sleep apnea in adults with obesity. It acts on two hormone receptors, GIP and GLP-1.
- Saxenda (liraglutide, Novo Nordisk): approved December 2014; once daily; adults and, since December 2020, teens 12 to 17. The first generic, from Teva, was approved in August 2025.
- Imcivree (setmelanotide, Rhythm Pharmaceuticals): once daily; approved for people 2 and older with Bardet-Biedl syndrome or genetically confirmed POMC, PCSK1 or LEPR deficiency, and on March 19, 2026 for acquired hypothalamic obesity in people 4 and older. It is not a general obesity drug.
In the main trials, adults without diabetes lost about 15% of body weight on average over 68 weeks on Wegovy and 15% to 21% over 72 weeks on Zepbound, compared with 2% to 3% on placebo. Our guide to GLP-1 weight loss results covers those trials, and liraglutide vs semaglutide compares the daily and weekly options. For how these drugs act in the body, see what GLP-1 is.
GLP-1 injections approved only for diabetes
Several well-known GLP-1 injections are approved for type 2 diabetes, not for weight management. Ozempic (semaglutide, December 2017), Mounjaro (tirzepatide, May 2022) and Trulicity (dulaglutide, September 2014) are used once a week, and Victoza (liraglutide, January 2010) once a day. Ozempic contains the same drug as Wegovy, and Mounjaro the same drug as Zepbound, but the labels differ in approved uses and strengths.
The FDA says that once a drug is approved, prescribers generally may use it for an unapproved purpose when they judge it medically appropriate. That is off-label use: the FDA has not reviewed the diabetes brands for weight management. See Wegovy vs Ozempic, Mounjaro vs Zepbound and Trulicity vs Ozempic for the label differences.
Compounded and "research" injections
Compounded semaglutide and tirzepatide spread while the brand drugs were in shortage. The FDA declared the tirzepatide shortage resolved on December 19, 2024 and the semaglutide shortage on February 21, 2025, and its temporary flexibility for compounders ended in 2025. Copies that are essentially the same as an approved drug are no longer allowed unless a prescriber documents a significant difference for that patient.
The FDA stresses that compounded drugs are not FDA-approved and are not reviewed for safety, effectiveness or quality before sale. As of May 31, 2026, it had received 990 adverse event reports linked to compounded semaglutide and more than 730 linked to compounded tirzepatide, some involving hospital stays possibly tied to mistakes in the amount given. It also warns that salt forms such as semaglutide sodium and semaglutide acetate are different active ingredients from the approved drugs. Read more in compounded semaglutide and tirzepatide.
Vials sold online as “for research purposes” or “not for human consumption” are a separate problem. The FDA says companies selling semaglutide, tirzepatide, retatrutide, survodutide or mazdutide this way are illegally selling unapproved drugs of unknown quality. Retatrutide is not FDA-approved for any use. Our guide to whether peptides are legal explains the rules.
Lipotropic, B12 and HCG shots
Med spas often sell “lipo” or MIC shots that combine methionine, inositol and choline, usually with vitamin B12. These are compounded products, not FDA-approved for weight loss, and we found no randomized trials in people showing that they reduce body fat. B12 injections are approved for B12 deficiency, not for weight. Our sibling guide to lipotropic injections covers them in detail.
HCG (human chorionic gonadotropin) is a pregnancy hormone sold as a prescription drug for female infertility and other conditions. The FDA states that it is not approved for weight loss, and the prescription label says in capital letters that HCG has not been shown to help with obesity and that there is no substantial evidence it increases weight loss beyond calorie restriction. On December 6, 2011, the FDA and the Federal Trade Commission sent warning letters to seven companies selling over-the-counter “homeopathic” HCG diet products. These plans usually pair HCG with a diet of about 500 calories a day, which the FDA says raises the risk of gallstones, electrolyte imbalance and an irregular heartbeat.
Are weight loss injections safe?
For the approved shots, the risks are known and printed on the label. Wegovy, Zepbound and Saxenda carry a boxed warning because the drugs caused thyroid C-cell tumors in rodents; whether this applies to people is unknown. The current Wegovy and Zepbound labels also warn about:
- Nausea, vomiting, diarrhea and constipation, sometimes severe; neither is recommended with severe gastroparesis.
- Acute pancreatitis and gallbladder disease, including gallstones.
- Kidney injury from dehydration after vomiting or diarrhea.
- Low blood sugar when combined with insulin or sulfonylurea-type diabetes drugs.
- Serious allergic reactions, including anaphylaxis and angioedema.
- Worsening diabetic eye disease in people with type 2 diabetes.
- Breathing food or liquid into the lungs during general anesthesia or deep sedation, so surgeons and anesthetists need to know about the medicine.
Unapproved products add risks that no label covers: the wrong amount of active ingredient, the wrong salt, contamination or a counterfeit. The FDA notes that poor compounding practices can lead to contamination or too much or too little drug. Sterility failures can be severe: in 2012, contaminated steroid injections from one compounding pharmacy caused an outbreak of fungal meningitis and other infections with 753 cases and 64 deaths in 20 states, according to the CDC. More detail on the approved drugs is in our guide to GLP-1 side effects.
Who should not use them
The GLP-1 based labels say not to use these drugs with a personal or family history of medullary thyroid carcinoma or multiple endocrine neoplasia type 2, or after a serious allergic reaction to the drug. They may harm a developing baby: the Wegovy label says to stop at least 2 months before a planned pregnancy, and the Zepbound label advises people on birth control pills to switch to, or add, a non-oral method for a period after starting and after each increase. The FDA also says Zepbound should not be combined with Mounjaro or another GLP-1 drug.
Pills instead of shots
Injections are no longer the only GLP-1 option for weight. Wegovy tablets were approved on December 22, 2025, and Foundayo (orforglipron), a non-peptide daily pill, on April 1, 2026; see our Wegovy pill guide and Foundayo guide. Older non-GLP-1 options include Qsymia, and our Ozempic alternatives guide lists the other approved choices.
Frequently Asked Questions
What are weight loss injections?
The term covers FDA-approved medicines such as Wegovy, Zepbound and Saxenda, diabetes drugs used off-label, compounded copies, unapproved “research” peptides, and med spa shots such as lipotropic, B12 or HCG injections. Only the first group is FDA-approved for weight management.
Which weight loss shots are FDA-approved?
Wegovy (semaglutide), Zepbound (tirzepatide), Saxenda (liraglutide) and generic liraglutide are approved for long-term weight management. Imcivree is approved only for certain rare genetic conditions and acquired hypothalamic obesity.
Are weight loss injections safe?
The approved ones have known risks listed on their labels, including stomach side effects, pancreatitis, gallbladder problems and a boxed warning about thyroid tumors in rodents. Compounded and “research” products have not been reviewed by the FDA, so their quality and contents are uncertain.
Is Ozempic approved for weight loss?
No. Ozempic is approved for type 2 diabetes. Wegovy contains the same drug, semaglutide, and is the brand approved for weight management.
Do HCG injections help with weight loss?
The FDA says HCG is not approved for weight loss, and its prescription label states there is no substantial evidence that it increases weight loss beyond calorie restriction.
Are there pills instead of GLP-1 injections?
Yes. Wegovy tablets were approved in December 2025 and Foundayo (orforglipron) in April 2026 for weight management.
Peptide Labs does not sell these drugs or injections. This article is general information, not medical advice. Read the Medication Guide or label that comes with any prescription, and ask a pharmacist or licensed prescriber how this information applies to you.
Last reviewed September 2026.
Related guides: GLP-1 for Weight Loss: What the Trials Actually Showed, Ozempic Alternatives: FDA-Approved Options, OTC Facts and What to Avoid, Compounded Semaglutide and Tirzepatide: What Is Allowed Now, Lipotropic Injections: What Is in MIC and B12 Shots, and Do They Work?.