Peptide safety basics | Living+ Peptides

Peptide safety depends a lot on what the product is. FDA-approved peptide drugs have labels that list known risks ^[4]. Compounded and unapproved peptides do not get FDA review for safety, effectiveness or quality before they are marketed, and FDA has named specific safety concerns for several of them ^{[1, 2]}.

Risks FDA names for unapproved peptides

FDA keeps a page on bulk drug substances that may present significant safety risks when used in compounding. Several peptides are on it ^[1]. FDA's concerns fall into a few groups:

Immune reactions. FDA says compounded drugs with some of these peptides may pose a risk for immunogenicity, meaning the body may react to them as foreign, for certain routes ^[1].
Impurities and clumping. FDA points to peptide-related impurities and the potential for aggregation, where peptide molecules clump together ^[1].
Unusual building blocks. FDA notes that GHRP-2 and ipamorelin contain unnatural amino acids, which make the peptides harder to characterize ^[1].
Little or no safety data. For BPC-157, FDA says it has no, or only limited, safety-related information for the proposed routes ^[1].

FDA also lists reported harms for some peptides. For CJC-1295, FDA cites serious adverse events including increased heart rate and a systemic vasodilatory reaction ^[1]. For GHRP-2, FDA notes reports of serious adverse events, including pancreatitis and deaths of critically ill study subjects, though causality has not been established ^[1]. You can read the details on our pages for BPC-157, CJC-1295, GHRP-2 and GHRP-6 and ipamorelin ^[1].

Risks FDA names for compounded drugs

FDA says compounded drugs are not FDA-approved. It does not verify their safety, effectiveness or quality before they are marketed ^[2]. FDA warns that poor compounding practices can lead to serious drug quality problems, such as contamination, which can lead to serious patient injury and death ^[2].

Compounded GLP-1 drugs show how this plays out. As of May 31, 2026, FDA had received 990 reports of adverse events tied to compounded semaglutide and more than 730 tied to compounded tirzepatide ^[3]. FDA says some reports, including some that needed hospital care, may be related to dosing errors ^[3]. FDA also says salt forms should not be used to compound semaglutide ^[3]. See semaglutide and tirzepatide for more ^[3].

FDA also warns about counterfeit drugs. These claim to be authentic but could contain the wrong ingredients ^[3].

Injection risks

Many peptide drugs are given as shots, including Ozempic ^[4]. Labels for approved peptide drugs describe risks linked to the shot itself ^[4]. The Ozempic label, for example, says pens must never be shared between patients, even if the needle is changed, because sharing poses a risk for transmission of blood-borne pathogens ^[4].

Shots can also cause reactions where they go in. In Ozempic's placebo-controlled trials, injection site reactions such as discomfort and redness were reported in 0.2% of patients on the drug ^[4]. Products made under poor conditions add another layer of risk, since FDA links poor compounding practices to contamination ^[2].

Immune and allergic reactions

The immune system can react to peptides. FDA lists immunogenicity as a concern for several compounded peptides ^[1]. Approved labels track this too. The Ozempic label reports that 32 of 3,150 patients (1%) developed anti-drug antibodies to semaglutide ^[4].

Serious allergic reactions can happen. The Ozempic label says serious hypersensitivity reactions, such as anaphylaxis and angioedema, have been reported ^[4].

How to report a problem to FDA

MedWatch is FDA's medical product safety reporting program for health professionals, patients and consumers ^[5]. You can use it to report serious reactions, product quality problems and product use errors ^[6].

Patients and consumers can use Form FDA 3500B, a consumer-friendly version ^[6].
Health professionals can use Form FDA 3500 ^[6].
You can report online, or call 1-888-INFO-FDA (1-888-463-6332) and press 2 for MedWatch ^[6].

FDA encourages health care professionals, patients and compounders to report adverse events or quality problems with GLP-1 drugs ^[3].

Where to go next

For an approved peptide drug, the FDA label lists its known risks, warnings and side effects ^[4]. For how peptide drugs reach patients, read how peptides are prescribed in the US. For FDA status, see the FDA Peptide Status Tracker ^[1].

Frequently asked questions

Are peptides safe?

It depends on the product. Approved peptide drugs have FDA labels listing risks, while FDA has flagged significant safety risks for several unapproved peptides used in compounding ^{[1, 4]}.

Are compounded peptides safe?

FDA does not verify the safety, effectiveness or quality of compounded drugs before they are marketed, and poor compounding practices can cause contamination ^[2].

Can your body make antibodies to a peptide?

Yes. FDA lists immunogenicity as a concern for several compounded peptides, and the Ozempic label reports anti-drug antibodies in 1% of patients ^{[1, 4]}.

What does FDA say about BPC-157 safety?

FDA says it has no, or only limited, safety-related information for BPC-157 by the proposed routes ^[1].

How many adverse events has FDA received for compounded semaglutide?

As of May 31, 2026, FDA had received 990 adverse event reports tied to compounded semaglutide ^[3].

How do I report a side effect to FDA?

Use FDA MedWatch. You can use the online reporting form or the consumer Form FDA 3500B, or call 1-888-463-6332 and press 2 ^[6].