FGF-1 vs Rigin

Binds all four FGFR subtypes (broadest binding of FGF family). Activates MAPK and PI3K downstream pathways. Promotes fibroblast proliferation, angiogenesis, and hair follicle cycling into anagen phase.

FGF-1 (fibroblast growth factor 1; acidic FGF; aFGF) is an endogenous 155-amino-acid heparin-binding growth factor and the prototypic member of the 22-member FGF family, expressed in diverse tissues where it stimulates cell proliferation, survival, and migration through tyrosine kinase receptor (FGFR1-4) signaling, with particularly important roles in angiogenesis, wound healing, and tissue repair. FGF-1 activates FGFR to initiate MAPK/ERK, PI3K/Akt, and PLCgamma signaling cascades driving endothelial cell sprouting and neovascularization; in ischemic tissues, FGF-1 is a potent inducer of therapeutic angiogenesis, stimulating new vessel formation to restore perfusion in peripheral arterial disease and critical limb ischemia. A Phase 2 randomized controlled trial of intramuscular gene-encoded FGF-1 delivery (NV1FGF, a non-viral plasmid vector) in critical limb ischemia demonstrated improved amputation-free survival in human subjects, providing clinical evidence for FGF-1 pathway activity; this gene therapy approach is distinct from direct recombinant FGF-1 protein administration, and no protein therapy form has completed Phase 3 trials. Recombinant FGF-1 protein has no FDA approval as a standalone therapeutic; the clinical evidence base references gene-encoded delivery rather than the protein itself, and research-grade FGF-1 is used primarily as a cell culture supplement and tissue engineering scaffold factor rather than as a therapeutically administered agent.

Palmitoylated tetrapeptide mimicking IgG C-terminal sequence; reduces IL-6 production in keratinocytes; combined with Matrixyl (Pal-GHK) forms Matrixyl 3000; anti-inflammatory and skin matrix support

Rigin (Palmitoyl Tetrapeptide-7) is a synthetic cosmetic peptide developed to address skin inflammation and age-related matrix degradation. It is proposed to suppress interleukin-6 (IL-6), a cytokine associated with chronic low-grade skin inflammation that accelerates extracellular matrix breakdown. Evidence for rigin is primarily derived from manufacturer-sponsored in vitro and ex vivo cosmetic research; no independent peer-reviewed clinical trials have been identified in indexed biomedical literature. Rigin is a cosmetic ingredient developed by Sederma/Croda; its evidence base consists of manufacturer-sponsored studies only and it has not been evaluated by regulatory agencies for any medicinal claim. Rigin and Matrixyl 3000 Rigin (Palmitoyl Tetrapeptide-7, Pal-GQPR) is one of two peptide actives in Sederma's Matrixyl 3000 formulation — the other being Matrixyl (palmitoyl pentapeptide-4, Pal-KTTKS). In the Matrixyl 3000 combination, the two peptides are proposed to address complementary aspects of skin aging: Matrixyl (Pal-KTTKS) stimulates new collagen I and III synthesis via TGF-β signaling; Rigin (Pal-GQPR) suppresses IL-6-mediated matrix degradation, reducing the rate at which newly synthesised collagen is broken down. The combination therefore targets both the anabolic (synthesis) and anti-catabolic (degradation prevention) sides of collagen matrix maintenance. This mechanistic pairing is the basis for the "3000" formulation's improved efficacy claims relative to the original single-peptide Matrixyl. In cosmetic formulations, Rigin is listed under its INCI name (Palmitoyl Tetrapeptide-7) and appears alongside palmitoyl pentapeptide-4 in products marketed as containing Matrixyl 3000. Typical concentration in the final product is in the range of 4–8% of the Sederma Matrixyl 3000 concentrate, which itself contains the peptides at a defined dilution. Rigin is a topical cosmetic ingredient — it has no injectable or clinical pharmaceutical application and does not require a prescription in any jurisdiction.