B7-33, Relaxin B-Chain Fragment
Evidence Grade E — Very limited evidence. 0 published studies. 0 registered clinical trials.
B7-33 is a simplified, single-chain version of the hormone relaxin, being investigated in preclinical research for heart and kidney fibrosis (scarring). Full-length relaxin requires complex two-chain assembly that makes manufacturing difficult — B7-33 solves this by delivering the key activity from one chain. No human clinical trials have been conducted. It has no regulatory approval.
No published studies found on PubMed.
B7-33 has no marketing authorisation. No human clinical trials have been registered. The evidence base consists entirely of preclinical studies in cell culture and animal models of cardiac and renal fibrosis.
B7-33's single-chain design solves a major manufacturing challenge — full-length relaxin requires complex two-chain assembly. If the biased agonism translates clinically, the simplified structure could make relaxin-based therapy practically viable. However, clinical translation has not yet been attempted.
Research suggests B7-33 activates the relaxin receptor (RXFP1) with a 'biased' signalling profile — selectively activating anti-fibrotic pathways while avoiding pathways that promote uncontrolled cell growth. This selectivity may offer safety advantages over full-length relaxin. These observations are from cell culture and animal studies.
Research suggests consistent anti-fibrotic results across multiple animal models, with a critical safety advantage: unlike full-length relaxin, B7-33 does not appear to promote tumour growth. Publication in high-quality journals and contributions from multiple research groups strengthen the evidence. However, the 6-minute half-life in blood is a major barrier to clinical translation. No human data of any kind exist, sample sizes in animal studies are small (6-8), and no formulation suitable for human use has been developed. Products from unregulated channels lack pharmaceutical quality assurance.
No trials registered on ClinicalTrials.gov for this compound.
The information on this page is provided for educational and research reference purposes only. This is not medical advice. Always consult a qualified healthcare professional before making any health-related decisions.
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