The medicine-quality map
What can go wrong, and where can I get help?
Ask about the exact product and its instructions. A broad peptide label does not give a useful answer about a particular medicine.
The sources for this page were checked between September 17 and September 26, 2026.
What can poor preparation do?
Compounding means making a custom medicine.
Poor preparation can introduce unwanted substances into medicine, explains the Food and Drug Administration (FDA), the agency responsible for US drugs.
It can also leave the wrong amount of the active ingredient.
The part of a medicine meant to produce its effect is called the active ingredient.
FDA does not check a custom medicine’s safety, how it works or how it is made before it reaches patients.
Errors in measuring custom semaglutide have been reported to FDA; some of these errors led to hospital care.
Do all peptides need to be kept cold?
No. Storage conditions depend on the product; some approved peptide medicines are kept at room temperature.
Get the storage instructions for the named medicine from its label and pharmacy.
For injections of semaglutide or tirzepatide, FDA warns against using a delivery that arrives warm or without enough cooling.
Which storage instructions apply to my product, and who do I contact about a delivery problem?
When is urgent help needed?
Trouble breathing or swallowing with swelling of the face or tongue can signal a severe allergy and calls for urgent help.
When symptoms point to a severe allergic reaction, dial 911 or seek care at the nearest emergency room, advises MedlinePlus—the US National Library of Medicine’s health information service.
Both patients and health professionals can send medicine-problem reports to FDA’s MedWatch program.
Reporting tells FDA about a problem so it can be checked. A report alone does not show whether the medicine caused it.
Reporting a problem does not replace getting medical help.
Find reporting and board routes