Peptide briefings
News & research briefings
Editorial synthesis of recent peptide research, FDA regulatory actions, and trial readouts. Each briefing is written from primary sources (PubMed, ClinicalTrials.gov, FDA) and cross-links back into the PeptaHub peptide graph.
- Regulatory·720 words
Peptide Reclassification Status — April 2026
HHS Secretary Kennedy signaled a return of ~14 peptides to 503A compounding. As of 2026-04-17, one Federal Register notice has published — and it is advisory, not a final rule.
- Safety·765 words
GLP-1s and Gastroparesis in 2026: Signal vs. Denominator
Adverse-event reports for GLP-1 gastroparesis have risen alongside prescribing. Raw counts don't establish risk — here's what the 2026 evidence base actually supports.
- Longevity·715 words
MOTS-c as an Exercise Mimetic: 2021–2025 Evidence
MOTS-c is a mitochondrial-derived peptide whose levels rise sharply with exercise. Recent work suggests it amplifies exercise adaptations — not that it replaces them.
- Trial update·770 words
GLP-1s and Primary Prevention: The SELECT Trial
SELECT showed a 20% MACE reduction in obese patients with prior CVD. Whether GLP-1s prevent first events without prior CVD is a separate, still-open question.
- Trial update·875 words
Retatrutide Evidence Into Mid-2026
The NEJM 2023 Phase 2 readout delivered up to 24.2% weight loss at 48 weeks. TRIUMPH-4 reported in December 2025; seven more Phase 3 readouts are expected through 2026.
- Safety·625 words
Melanotan II Safety in 2026: Case-Report Evidence
Peer-reviewed case reports have documented melanoma, renal infarction, and priapism linked to melanotan II since 2011 — the evidence has not aged well for cosmetic use.
- Regulatory·820 words
FDA Compounding Crackdown 2025: GLP-1 Access, Reshaped
The FDA declared the semaglutide and tirzepatide shortages resolved in 2025 and issued 50+ warning letters to compounders — here is what actually shifted.