CGRP vs Thymulin

Binds CLR/RAMP1 receptor complex. Causes vasodilation via cAMP/PKA/nitric oxide pathway. Modulates nociceptive signaling in the trigeminal system. Promotes bone healing and has anti-inflammatory effects in peripheral tissues.

CGRP (calcitonin gene-related peptide) is a 37-amino-acid endogenous neuropeptide produced by alternative splicing of the calcitonin gene, expressed predominantly in sensory neurons of the trigeminal system and peripheral vasculature, where it functions as a potent vasodilator and pain neuromodulator central to migraine pathophysiology. CGRP activates its receptor complex (CLR/RAMP1) to mediate vasodilation and nociceptive signal amplification; during migraine attacks, trigeminal activation releases CGRP at elevated plasma concentrations, and blockade of this pathway has been established as the primary validated pharmacological target for modern preventive migraine therapy. Phase 3 randomized controlled trials published in the New England Journal of Medicine and the Lancet — including the STRIVE trial (Goadsby et al. 2017) and a Phase 3b study in treatment-refractory patients — demonstrated that anti-CGRP monoclonal antibodies significantly reduced monthly migraine days versus placebo, validating the pathway and supporting FDA approval of erenumab, fremanezumab, and galcanezumab. CGRP itself is an endogenous neuropeptide and is not a therapeutic agent that is compounded or administered by providers; the FDA-approved interventions are monoclonal antibody and small-molecule receptor antagonists available by prescription, and exogenous CGRP peptide is exclusively a research tool compound used in vasodilatory and pain signaling pharmacology studies.

Zinc-dependent peptide that promotes T-lymphocyte differentiation, enhances natural killer cell activity, and regulates cytokine balance. Requires zinc cofactor for biological activity.

Thymulin (facteur thymique serique; FTS) is an endogenous zinc-dependent nonapeptide (Glu-Ala-Lys-Ser-Gln-Gly-Gly-Ser-Asn) produced exclusively by thymic epithelial cells, identified by Dardenne and Bach in the 1970s as the circulating thymic hormone responsible for promoting T-cell differentiation and maturation in the peripheral immune system. Biological activity of thymulin requires chelation of a zinc ion to form an active complex; the zinc-thymulin complex binds to receptors on immature T-lymphocytes promoting their differentiation, and modulates the neuroendocrine-immune axis through interactions with pituitary hormones, with blood levels of active thymulin declining measurably with age and zinc deficiency. Published reviews from the Dardenne (Institut Pasteur) and Goya groups have established thymulin as a key mediator of thymic-dependent immune senescence, with preclinical data in aged animal models demonstrating partial restoration of immune function following exogenous administration; no human randomized controlled trials have been published. Thymulin has no FDA approval and no approved therapeutic indication in any major jurisdiction; it is a research compound with biological plausibility for immune senescence applications, though the exclusively preclinical evidence base and the zinc-dependency of its active form represent important limitations for any discussion of exogenous supplementation.