What is the FDA saying about my peptides?
You might have noticed some of your favorite peptides are getting harder to find. That is because the FDA has moved several of them into Category 2. This is a specific list for substances that have significant safety risks or lack enough data to prove they are safe for routine custom mixing by pharmacies.
As of March 2026, the following peptides are on this restricted list due to concerns like immunogenicity (when your immune system overreacts to a substance) or a simple lack of human safety data:
- BPC-157: Listed as a significant safety risk with concerns about the immune system.
- TB-500: The FDA cites risks to the immune system and a lack of data on how it affects humans.
- CJC-1295: Removed from routine pharmacy mixing due to safety issues like an increased heart rate.
- GHK-Cu: Not approved as an injectable drug due to immune system risks.
Wait, I thought these were common?
It turns out the rules are tightening up. Companies like Tailor Made Compounding and Predator Nutrition actually received warning letters from the FDA regarding these substances. Even peptides that are used in other countries, like Thymosin Alpha-1 (approved in 35+ countries as Zadaxin), are still considered substances of concern by the FDA and are not approved in the United States.
What about the big names like Semaglutide?
While Semaglutide is FDA-approved, the FAERS (a database that tracks bad reactions reported by patients and doctors) shows some strong signals we should talk about.
- Stomach Troubles: Nausea and vomiting are very common and usually managed by slowly increasing the dose.
- Digestion Delays: It can cause delayed gastric emptying (food staying in your stomach too long), which might affect how you absorb other pills.
- Gallbladder and Kidneys: There are reports of gallbladder stones and kidney injury, often linked to dehydration from stomach issues.
- New Warnings: In 2025, a warning was added to the label about pulmonary aspiration (food or liquid getting into the lungs) during surgery because of that slow digestion.
Are the clinical trials showing anything good?
Yes, the data is not all warnings. In the STEP 1 trial, Semaglutide showed a 14.9% weight loss, and the SELECT trial showed a 20% reduction in major heart problems. Meanwhile, Tirzepatide showed a 22.5% weight loss in its SURMOUNT-1 trial, and Retatrutide is currently hitting 24.2% in Phase II studies.
However, not every trial is a win. A Phase III trial for Thymosin Alpha-1 for sepsis (a life-threatening infection response) came back negative, showing no reduction in deaths.
This is a great one to bring up with your doctor. You can find peptide-experienced physicians in our Find a Doctor directory.
This content is sourced exclusively from TruthTides clinical reference data and does not constitute medical advice.
Referenced Peptides
This content was generated from TruthTides clinical reference data. It does not constitute medical advice. Always consult a qualified healthcare provider.