B7-33
A synthetic relaxin-derived peptide that halts and reverses pathological tissue fibrosis in the heart, lungs and kidneys without causing a sharp drop in blood pressure.
B7-33 is a synthetic peptide functionally derived from the hormone relaxin-2, made of a single soluble chain representing a truncated, optimised version of the hormone's B chain. It was designed to overcome the structural complexity and high production cost of two-chain relaxin. It acts as a specific biased agonist of relaxin family peptide receptor 1 (RXFP1). B7-33 is highly effective at activating the pERK-MMP signalling pathway (responsible for breaking down accumulated collagen, countering fibrosis and promoting vasodilation) without activating the cyclic AMP (cAMP) pathway, which may be linked to unwanted proliferative effects. This makes it an exceptional candidate in research on organ fibrosis, heart failure and vascular disease.
The cellular dissolver of fibrosis and the strongest engineered alternative to the hormone relaxin
If you are looking for the therapeutic power of relaxin in treating organ scarring and loosening stiff fibrotic tissue, but without its molecular complexity and biological risks, B7-33 is the breakthrough designed to engineer this pathway with great precision.
Classification: Anti-fibrotic peptides, protection of vital organs, RXFP1-receptor activation (Antifibrotic / Cardioprotective / Relaxin Mimetics).
Structurally, it is a single peptide chain derived from the B chain of human relaxin-2, designed to be chemically stable and easier to manufacture and target biologically than the complex natural hormone.
Picture the heart muscle, lungs or kidneys after chronic inflammation or stress: networks of hard collagen begin to build up like set cement, restricting the organ's flexibility, gradually choking it and taking away its ability to work.
How it works
B7-33 binds RXFP1 receptors on the cell surface with high specificity, but exerts a smart, biased activation: it stimulates pERK kinase signals that release matrix metalloproteinase enzymes (MMPs) — the biological scissors responsible for dissolving and breaking down hardened collagen fibres and restoring tissue flexibility. At the same time, it avoids stimulating the cAMP pathway, sidestepping unwanted cell-proliferation pathways. The result is reduced heart-muscle fibrosis, better arterial flexibility and protection of liver and lung tissue from advanced scarring, without causing a sharp fall in blood pressure.
In research, it is studied in models of chronic heart failure, idiopathic pulmonary fibrosis, scleroderma and fibrotic kidney disease, with the aim of restoring flexibility to exhausted vital organs.
Rescuing damaged organs is not just about easing symptoms — it lies in sending cellular tools that can break down old scarring and rebuild flexible living tissue.
Breaking down fibrosis and restoring flexibility to vital organs. B7-33 is the advanced engineering achievement that mimics natural relaxin and frees tissues from hard scarring. It belongs to the class of peptides that counter organ fibrosis and protect the circulatory system. Its smart single-chain structure binds directly to RXFP1 receptors on cell walls, sending precise activation signals to the enzymes that break down collagen accumulated around the heart muscle, blood vessels, kidneys and lungs. Its unique mechanism dissolves fibrous hardening without activating pathways that could lead to uncontrolled cell growth, helping restore tissue flexibility, improve blood flow and relieve organs strained by chronic scarring. Scientists study it as a revolutionary compound for treating cardiac and pulmonary fibrosis and restoring vitality to hardened organs with outstanding efficiency and molecular safety — because real recovery begins by freeing cells from the fibrous restraints that stifle them.
