Side effects · Latest table check
This site shows side effect tables for 9 of the 34 peptides it reviews. 7 come from FDA product labels. 2 come from trials of drugs that are not FDA-approved. Each table compares people who got the drug with people who got a placebo, a dummy treatment with no medicine in it.
For 4 more, an FDA-approved label describes the risks, but this site has no table yet. For the other 21, our review rates what is known about their risks as limited or unclear.
Many peptides sold online were never tested well in people, so no one knows how often problems happen.
| Peptide | FDA status | Where the numbers come from |
|---|---|---|
| Abaloparatide | FDA-approved product | FDA labelChecked |
| Bremelanotide | FDA-approved product | FDA labelChecked |
| Liraglutide | FDA-approved product | FDA labelChecked |
| Semaglutide | FDA-approved product | FDA labelChecked |
| Teriparatide | FDA-approved product | FDA labelChecked |
| Tesamorelin | FDA-approved product | FDA labelChecked |
| Tirzepatide | FDA-approved product | FDA labelChecked |
| Cagrilintide | No FDA-approved product | Trial registry resultsChecked |
| Retatrutide | No FDA-approved product | Trial registry results and company trial resultsChecked |
Company trial results were not yet checked by outside experts when we read them. Registry results are posted by the trial sponsor on ClinicalTrials.gov.
These pages show the tables from two FDA labels one after the other. Each table keeps its own placebo numbers. The labels say rates from different trials cannot be directly compared.
FDA label · FDA-approved product
The Tymlos label lists high calcium in the urine, dizziness, nausea, and headache as the most common side effects in women after menopause. For example, dizziness was reported by 10% of women on Tymlos and 6% on placebo. In men, redness where the shot was given and dizziness were most common. The label also says Tymlos can raise heart rate and blood calcium for a few hours after a shot.
See the Abaloparatide tablesFDA label · FDA-approved product
The Vyleesi label lists nausea, flushing, reactions where the shot was given, and headache as the most common side effects. In its two main trials, nausea was reported by 40.0% of women on Vyleesi and 1.3% on placebo. Vyleesi also raises blood pressure for a few hours after a dose. Some women got dark patches on the skin. These label numbers do not describe PT-141 sold online.
See the Bremelanotide tablesFDA label · FDA-approved product
The Victoza and Saxenda labels list nausea, diarrhea, vomiting, and constipation as the most common side effects. In the Saxenda weight trials, nausea was reported by 39.3% of adults on Saxenda and 13.8% on placebo. The labels also warn about pancreatitis, gallbladder problems, and low blood sugar when liraglutide is taken with some diabetes medicines. Both labels have a boxed warning about thyroid tumors seen in rats and mice.
See the Liraglutide tablesFDA label · FDA-approved product
The Ozempic and Wegovy labels list nausea, diarrhea, vomiting, constipation, and belly pain as the most common side effects. In the Wegovy weight trials, nausea was reported by 44% of adults on Wegovy and 16% on placebo. The labels also warn about pancreatitis, gallbladder problems, and low blood sugar when semaglutide is taken with some diabetes medicines. Both labels have a boxed warning about thyroid tumors seen in rodents.
See the Semaglutide tablesFDA label · FDA-approved product
The Forteo label names joint pain, pain, and nausea as the most common side effects. In its two main trials, joint pain was reported by 10.1% of people on Forteo and 8.4% on placebo. Nausea was reported by 8.5% and 6.7%. Many problems were almost as common on placebo. The label also says Forteo raises blood calcium for a few hours after a shot.
See the Teriparatide tablesFDA label · FDA-approved product
The Egrifta label lists shot-site reactions, joint pain, arm or leg pain, muscle pain, and leg swelling as common side effects. Shot-site reactions affected 17% of people on Egrifta and 6% on placebo. The label also warns about blood sugar, IGF-1, fluid buildup, and allergic reactions. It must not be used with active cancer or during pregnancy. These numbers do not describe tesamorelin sold online.
See the Tesamorelin tablesFDA label · FDA-approved product
The most common side effects in the Mounjaro and Zepbound labels include nausea, diarrhea, vomiting, constipation, indigestion, and belly pain. In the Zepbound weight trials, nausea was reported by 25% to 29% of adults on Zepbound and 8% on placebo. The labels also warn about pancreatitis, gallbladder problems, kidney injury from fluid loss, serious allergic reactions, and low blood sugar, especially with insulin or a sulfonylurea. Both labels have a boxed warning about thyroid tumors seen in rats.
See the Tirzepatide tablesTrial registry results · No FDA-approved product
In its phase 2 trial, the most common side effects were stomach and bowel problems, mainly nausea and constipation. ClinicalTrials.gov results show nausea in 19.8% to 46.5% of the cagrilintide groups and 17.8% on placebo. Tiredness and redness where the shot was given were also more common than on placebo. Cagrilintide is not FDA-approved, and its long-term risks are not known.
See the Cagrilintide tablesTrial registry results and company trial results · No FDA-approved product
In trials, the most common side effects were nausea, diarrhea, constipation, and vomiting. In TRIUMPH-1, Lilly, the company that makes retatrutide, reported nausea in 28.6% to 42.4% of people on retatrutide and 14.8% on placebo. These are early company results. In a phase 2 trial, most stomach and bowel side effects were mild to moderate. Some people also reported dysesthesia, an unpleasant or unusual feeling on the skin. Rare and long-term risks are not known yet.
See the Retatrutide tablesA number in a table is the share of people in a study who reported a problem. It is not your own chance of having it.
Compare the drug column with the placebo column. Some problems happen without any drug.
Check who was studied. People in a trial may differ from you in age, health, and other medicines.
Rare or long-term harms often do not show up in trials. Labels list serious risks in separate warnings, not only in the table.
A product bought online may not match the product that was tested.
An FDA-approved product label describes the known risks for these. This site has no side effect table for them yet. A strong rating means the risks are well described. It does not mean the drug is low-risk.
The label and postauthorization monitoring characterize known risks and skin-monitoring requirements.
Product labels and many years of use describe the main risks, especially dangerously low blood sugar.
The approved label describes injection-site reactions and serious allergic reactions. It does not define the long-term risks of every SS-31 product.
The label addresses neoplastic growth, obstruction, biliary and pancreatic disease, and fluid imbalance.
Our review rates what is known about the risks of these as limited or unclear. For most, studies in people were small, short, or missing, so uncommon and long-term harms are not known. The note under each name gives the reason and the FDA status.
Clinical safety reporting is incomplete, and FDA identifies immunogenicity and impurity concerns.
What FDA has said about AOD-9604 safetyThe human safety dataset is too small for confident risk estimates.
What FDA has said about BPC-157 safetyRead the BPC-157 side effects guideThe stroke evidence found a possible increase in serious health problems that did not cause death. Product information also lists important warnings and adverse effects.
The studies were short. FDA reports serious unwanted events, limited clinical data, and concerns about unwanted material in peptide products.
What FDA has said about CJC-1295 safetyFDA found no adequate long-term safety data and no human safety evidence for the proposed under-the-skin route. Product quality and immune-reaction risks remain uncertain.
What FDA has said about DSIP safetyHuman product, route, exposure, impurity, and long-term safety data are inadequate.
What FDA has said about Epitalon safetyHuman information is limited, and FDA identifies injectable immunogenicity and impurity concerns.
What FDA has said about GHK-Cu safetyFDA lists possible immune reactions from peptide impurities or aggregation, plus possible cortisol and blood-sugar effects. Human studies are too small and brief to show uncommon or long-term harms.
What FDA has said about GHRP-6 safetyFormer product records and human studies provide limited safety information. They do not define uncommon harms or the safety of current unapproved products.
Route-specific data are sparse and FDA identifies serious safety concerns.
What FDA has said about Ipamorelin safetyThe studies were small and brief. They cannot show uncommon harms or long-term safety.
What FDA has said about Kisspeptin-10 safetyFDA says there is not enough safety information. It notes possible immune reactions, impurities, and uncertainty about product contents. Animal and cell findings do not prove harm in people.
What FDA has said about LL-37 safetyThe safety record is case reports plus a review. They establish that serious events have occurred, not how often.
What FDA has said about Melanotan II safetyHuman exposure, immunogenicity, long-term effects, and route-specific safety are unresolved.
What FDA has said about MOTS-c safetyAnimal findings cannot set a safe amount or show uncommon or long-term harms in people.
Small studies cannot show uncommon or long-term harms. FDA says important human safety information is missing for the Selank acetate form.
What FDA has said about Selank safetyMost safety reports were small or incomplete. FDA found no under-the-skin (subcutaneous) safety data and raised impurity, peptide-clumping (aggregation), immune-response, and bleeding concerns.
What FDA has said about Semax safetyPast records do not fully show whether modern compounded products are safe. They also do not show the safety of long-term use for wellness.
Human exposure and product-specific safety information are inadequate.
What FDA has said about TB-500 safetyThe large sepsis study found no clear safety difference, but FDA says important safety questions remain for compounded products.
What FDA has said about Thymosin alpha-1 safetyThe cited human studies cover specific research material and routes. They do not establish the safety of other VIP products or long-term use.
You can report a suspected side effect to the FDA at 1-800-FDA-1088 or through FDA MedWatch . If a reaction feels serious, get medical care first.