Recovery & Healing

B7-33

B7-33 (Single-Chain Relaxin Analog)

Simplified relaxin peptide targeting organ fibrosis

B7-33 is a single-chain analog of the hormone relaxin-2, developed to retain its anti-fibrotic and vasodilatory effects while being easier to manufacture than the native two-chain molecule.

B7-
💉

Admin routes

Subcutaneous

🔬

Popularity

Niche

✅

Side effects

Generally mild

🏪

AU vendors

0 rated

✓Key benefits

1Reduced cardiac fibrosis in animal models
2Anti-fibrotic effects comparable to native relaxin-2
3Easier and cheaper to manufacture than two-chain relaxin
4Vasodilatory effects through nitric oxide pathway

📈What to expect

1
N/A

No human data available. Animal studies showed anti-fibrotic effects over 2-4 weeks of treatment.

Based on community reports and published research. Individual results vary significantly.

💊Dosing protocols

Research reference (animal studies)

Dose

0.5 mg/kg/day

Frequency

Daily infusion (animal protocol)

Duration

14-28 days in published studies

Dosing information is sourced from published research and community protocols. This is not a recommendation. Consult a healthcare professional.

Research status|Preclinical - animal models of fibrosis

Overview

Relaxin-2 is a naturally occurring hormone with potent anti-fibrotic and vasodilatory effects, but its two-chain structure (similar to insulin) makes it expensive and difficult to produce. B7-33 was designed by Hossain et al. at the Florey Institute in Melbourne as a simplified single-chain version that activates the same RXFP1 receptor. In animal models, B7-33 reduced cardiac and lung fibrosis. The compound represents a practical approach to making relaxin-based therapy accessible.

⚙️How it works

B7-33 selectively activates the relaxin family peptide receptor 1 (RXFP1). Activation triggers downstream signalling through cAMP, nitric oxide, and matrix metalloproteinase pathways. This leads to collagen degradation, reduced myofibroblast differentiation, and increased tissue compliance. In the cardiovascular system, RXFP1 activation produces vasodilation and reduces cardiac remodelling after injury.

⚡Side effects

Hypotension from vasodilation (theoretical in humans)
moderateUncommon

📅Research history

2016

Hossain et al. publish B7-33 as a functional single-chain relaxin analog

References

  1. [1]Hossain MA, et al. 'A single-chain derivative of the relaxin hormone is a functionally selective agonist of the G protein-coupled receptor, RXFP1.' Chemical Science, 2016.

Frequently asked questions

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Disclaimer: This guide is for educational and informational purposes only. It is not medical advice. The dosing protocols listed are sourced from published research and community reports and do not constitute a recommendation. Always consult a qualified healthcare professional before using any peptide. Australian regulations classify many peptides as Schedule 4 (prescription-only) substances. Check current TGA guidelines before purchasing.