Discover B7-33 dosage trends, reconstitution volumes, and vial size patterns from anonymized WPA peptide calculator sessions.
B7-33 is a single-chain analog of human relaxin-2, engineered to retain the cardioprotective and anti-fibrotic signaling of native relaxin while improving peptide stability. Research has focused on its potential in heart failure, pulmonary fibrosis, and renal protection. This data captures the dose amounts, vial sizes, and bacteriostatic water volumes researchers most commonly select when reconstituting B7-33.
B7-33 is a single-chain peptide analog of human relaxin-2 engineered to retain the cardioprotective and anti-fibrotic receptor-signaling of native relaxin while improving chemical stability and eliminating the need for the A-chain/B-chain disulfide chemistry that makes native relaxin expensive and technically demanding to synthesize. The molecule was developed at the Howard Florey Institute (now Florey Institute of Neuroscience and Mental Health) in Melbourne, Australia, primarily through the work of Mohammed Akhter Hossain and colleagues, and published in the landmark Hossain et al. Nature Chemical Biology 2016 paper that characterized the engineered single-chain construct and demonstrated RXFP1 agonist activity in rodent models.
B7-33 is a single-chain peptide analogue of the B-chain of human relaxin-2 (H2 relaxin), engineered by the Bathgate group at the Florey Institute to retain the anti-fibrotic and vasodilatory signalling of the parent hormone while eliminating the disulfide-bridged A-chain that makes full-length relaxin difficult and expensive to manufacture. It is an unapproved research peptide with no human trials reported.
B7-33 binds the relaxin-family peptide receptor RXFP1 with lower affinity than native H2 relaxin but appears biased toward the ERK1/2 / MMP-2 signalling arm that drives reductions in collagen deposition, rather than the cAMP arm. This signalling bias is the proposed reason a much weaker binder still produces comparable anti-fibrotic effects in animal models.
No regulatory approvals exist anywhere in the world. Reported pre-clinical activity in rodent models of cardiac fibrosis, acute heart-failure haemodynamics, pre-eclampsia and renal ischemia–reperfusion injury. **Typical dose:** No human dose has been established. Pre-clinical mouse and rat studies have used 5–25 µg/kg/day subcutaneous or osmotic-pump infusion for 7–28 days.
B7-33 has a reported half-life of ~15 min (estimated), and the dose intervals researchers model most often fall around once daily. Very short-lived in the blood, so it acts as a brief pulse with no accumulation. Frequency and timing matter more than total dose. It is catalogued under Recovery Peptides on WPA.
1 B7-33 reconstitution calculations have been logged by the WPA community. The most common dose entered is 10mcg (1 calculations). The most common bacteriostatic water volume is 0.5mL. The most popular vial size is 1mg (1 sessions). The most common dosing frequency is daily (7x/week) (1 logged protocols).
These figures come from anonymized WPA peptide calculator sessions.
All figures shown are aggregated from anonymized calculator inputs and are provided strictly for independent laboratory research and educational purposes. They are community usage statistics — not dosing recommendations, and not medical advice.