Retatrutide vs. Tirzepatide: Where the 2026 Research Stands
A literature roundup comparing the peer-reviewed trial data behind retatrutide and tirzepatide — and why no head-to-head study between them has been published.
Research News
Research News
Research News
Research News
New Peptide Research Published This Quarter (Q2–Q3 2026)
A recurring roundup of newly published, PubMed-indexed peptide research — this installment covers BPC-157's first human safety data and a new NAD+ precursor trial.
All content on this page is for laboratory and academic reference only. This compound is supplied under a Research Use Only framework for in vitro and preclinical investigation by qualified personnel. Nothing on this page is clinical guidance, and it should not be interpreted as instructions for use in humans or animals.
Key Takeaways
- BPC-157 received its first published human pharmacokinetic/safety data in 2025 — a small pilot study of intravenous infusion, more than two decades after the compound's earliest preclinical literature.[1]
- A 2025 systematic review of BPC-157 in orthopedic sports medicine found only one qualifying human clinical study out of 544 screened articles, underscoring how preclinical-heavy this literature remains.[2]
- A March 2026 review consolidated BPC-157's reparative and pain-modulation research across musculoskeletal, gastrointestinal, and neurological models.[3]
- A November 2025 randomized controlled trial studied the NAD+ precursor nicotinamide riboside for cognition and symptom recovery in long-COVID patients.[4]
- This roundup only includes items that were peer-reviewed and PubMed-indexed at time of writing — press-release-only topline results (such as retatrutide's 2026 phase 3 announcements) are covered separately, and explicitly flagged as pending peer review, in the Retatrutide vs. Tirzepatide article on this blog.
What It Is
This is the first installment of a recurring roundup covering newly published, PubMed-indexed research relevant to the compounds in this catalog. Each installment will be dated to the period it covers and will only include items that have cleared peer review and received a PubMed listing — topline press-release results, preprints, and conference abstracts are excluded from this series unless explicitly labeled as such, to keep this a source of verified literature rather than industry announcements.
Mechanism & Pathway
This installment's most notable development is BPC-157's first published human data. BPC-157 has an unusually large preclinical literature relative to its human research — the 2025 pilot safety study of intravenous BPC-157 infusion represents one of the first formal attempts to characterize the compound's behavior in human subjects rather than animal models, reporting no adverse effects at the doses studied in a small cohort.[1] A companion systematic review searching for human BPC-157 evidence in orthopedic sports medicine specifically illustrates the gap: of 544 screened articles, only one human clinical study met inclusion criteria, with the review's authors noting that extensive preclinical evidence has not yet been matched by controlled human trials.[2] Separately, a NAD+-adjacent trial examined nicotinamide riboside (an oral NAD+ precursor, mechanistically distinct from direct NAD+ administration) in a randomized, controlled long-COVID cognition study — part of a broader, ongoing pattern of NAD+ precursor research in clinical populations.[4]
Research Domains
- BPC-157: first human safety data — a pilot study of intravenous BPC-157 infusion reported no adverse effects in a small cohort of healthy adults — one of the first formal human safety assessments published for this compound.[1]
- BPC-157: evidence-gap systematic review — a systematic review of orthopedic sports medicine literature found only one qualifying human study among 544 screened articles.[2]
- BPC-157: consolidated mechanism review — a March 2026 review summarized reparative and analgesic research across musculoskeletal, gastrointestinal, and pain-modulation domains.[3]
- NAD+ precursor research — a randomized controlled trial studied nicotinamide riboside for cognitive and symptom-recovery outcomes in a long-COVID patient population.[4]
Comparative Notes
The throughline across this installment is the gap between preclinical and human research that characterizes much of this catalog's literature. BPC-157 in particular has decades of animal-model data but only just received its first published human pharmacokinetic/safety work in 2025 — researchers relying on BPC-157's mechanism-of-action literature (see the dedicated BPC-157 research guide) should keep in mind that most of that evidence base remains preclinical.
Certificate of Analysis: What to Look For
Not applicable to this roundup format — see the dedicated research overview for each individual compound for COA guidance specific to that product.
References
- Lee E, Burgess K (2025). Safety of Intravenous Infusion of BPC157 in Humans: A Pilot Study. Alternative Therapies in Health and Medicine. PMID: 40131143
- Vasireddi N, Hahamyan H, Salata MJ, Karns M, Calcei JG, Voos JE, Apostolakos JM (2025). Emerging Use of BPC-157 in Orthopaedic Sports Medicine: A Systematic Review. HSS Journal. PMID: 40756949
- Yuan C, Demers A, Silva-Ortiz V, Hasoon JJ, Lee W, Dave K, Amirdelfan K, Burke HW, Christo PJ, Robinson CL (2026). From Regeneration to Analgesia: The Role of BPC-157 in Tissue Repair and Pain Management. International Journal of Molecular Sciences. PMID: 41898733
- Wu CY, Reynolds WC, Abril I, McManus AJ, Brenner C, González-Irizarry G, Gutiérrez-Martínez L, Sun O, Rosand J, Tanzi RE, Arnold SE, Guzmán-Vélez E (2025). Effects of nicotinamide riboside on NAD+ levels, cognition, and symptom recovery in long-COVID: a randomized controlled trial. EClinicalMedicine. PMID: 41357333
FAQ
This series is intended to be updated quarterly with newly published, peer-reviewed, PubMed-indexed research relevant to compounds in this catalog.
BPC-157's first published human safety data — a pilot intravenous infusion study — more than two decades after the compound's earliest preclinical research.[1]
No. This series only includes items that have cleared peer review and received a PubMed listing at time of writing. Topline press-release announcements are covered separately and explicitly labeled as pending peer review where relevant.
No. Nicotinamide riboside is an oral NAD+ precursor that is metabolized into NAD+ within cells — a mechanistically distinct research approach from direct NAD+ administration. See the dedicated NAD+ research overview for more detail.[4]
See the dedicated BPC-157 research guide on this blog, which covers the compound's VEGFR2/angiogenesis and growth-hormone-receptor mechanisms with full citations.
Related Guides
FDA Compounding Policy Update: What It Means for RUO Peptide Supply
A summary of recent regulatory developments affecting compounding and research-use peptide supply chains.
Selank vs. Semax: Comparing Two Russian Neuropeptide Research Lines
A side-by-side look at Selank and Semax — two ACTH/tuftsin-derived heptapeptides from the same research tradition, their distinct mechanisms, and the one study that examined both together.