Also known as Adrenocorticotropic hormone · Corticotropin · Acthar · Cosyntropin (1–24 analog) · Tetracosactide
The pituitary’s command to the adrenal gland — a 39-amino-acid hormone that drives cortisol release; its 1–24 fragment is the standard test of adrenal function.
Research refreshed
ACTH is a 39-amino-acid hormone released by the anterior pituitary that tells the adrenal cortex to make cortisol — the central relay of the body’s stress (HPA) axis. Clinically it appears in two forms: the full-length hormone as a long-acting gel (Acthar) used in select inflammatory and seizure conditions, and the synthetic 1–24 fragment cosyntropin (tetracosactide), which carries all the receptor activity and is the standard agent for testing adrenal reserve.
ACTH is the middle link in the hypothalamic–pituitary–adrenal axis: the hypothalamus releases CRH, the pituitary responds with ACTH, and ACTH drives the adrenal cortex to secrete cortisol, which then feeds back to shut the loop. It is cleaved from a larger precursor, proopiomelanocortin (POMC), the same parent that yields melanocyte-stimulating hormone — which is why high ACTH states can darken the skin.
Only the first 24 of its 39 residues are needed for full biological activity, and that fact is the basis of its main diagnostic use. Cosyntropin (synthetic ACTH 1–24) is given in the "ACTH stimulation test": a healthy adrenal gland responds with a brisk rise in cortisol, whereas a blunted response reveals adrenal insufficiency. The trimmed fragment is cheaper, fully active, and less immunogenic than the whole hormone.
The full-length hormone has a separate, more debated life as a therapeutic. Long-acting corticotropin gel (Acthar) is used in conditions such as infantile spasms and certain flares of autoimmune disease, on the rationale that it does more than simply raise cortisol — including direct melanocortin-receptor effects. Its high cost relative to conventional steroids has made it a recurring subject of pricing scrutiny, another instance where the economics around a hormone are as notable as its biology.
Agonist at the melanocortin-2 receptor (MC2R) on adrenocortical cells, raising cAMP and stimulating steroidogenesis — chiefly cortisol — from the adrenal cortex. The biologically essential activity resides in the N-terminal 1–24 residues.
Behind every vial of ACTH (Corticotropin) is the same exacting pipeline every research peptide runs — but the chemistry plays out differently for this molecule. Here is how ACTH (Corticotropin), specifically, is brought into being.
On paper, ACTH (Corticotropin) weighs in at roughly 4,541.1 daltons. Before a single bond is made, the target sequence, salt form, and purity threshold are written down as the contract the finished material must meet.
ACTH (Corticotropin) is built one protected residue at a time by solid-phase synthesis, each cycle a deprotection, a coupling, and a wash.
The crude mixture — ACTH (Corticotropin) plus its deletions and side products — is then separated on preparative HPLC, and where the cut is taken decides the difference between a genuinely pure peptide and a barely-passable one.
A real batch of ACTH (Corticotropin) proves itself: identity confirmed by mass spectrometry against its ~4,541.1 Da, purity read directly off an analytical HPLC trace, water and counterion content measured. That batch-specific certificate of analysis is the only honest way to know what is actually in a vial of ACTH (Corticotropin) — and a short, cold, accountable chain of custody is how that purity survives the trip to your bench.
A 39-residue hormone whose full biological activity lives in the N-terminal 1–24 segment — so the synthetic agent cosyntropin (tetracosactide) is simply that 24-mer. Truncating to the essential pharmacophore makes it markedly shorter and cheaper to build by solid-phase synthesis, avoids the difficult C-terminal residues, and lowers immunogenicity versus the whole hormone. A textbook "synthesize only the part that matters" decision in peptide drug design.
Don't judge a vial by its cake. A fluffy, good-looking lyophilized powder reflects bulking agents and freeze-drying parameters — not purity. Insist on a batch-specific certificate of analysis.
Recent clinical trials and publications mentioning Adrenocorticotropic hormone, pulled automatically from ClinicalTrials.gov and PubMed and refreshed daily. Listings are unfiltered search results, not curated endorsements.
ACTH (corticotropin) is a pituitary hormone that signals the adrenal cortex to release cortisol. It is the pituitary-to-adrenal step of the body’s stress (HPA) axis.
Cosyntropin (tetracosactide) is the synthetic first 24 amino acids of ACTH — the portion that carries all the activity. It is used in the ACTH stimulation test to assess whether the adrenal glands respond normally.
The long-acting full-length hormone (Acthar) is used in conditions like infantile spasms and some autoimmune flares, but its very high cost relative to conventional corticosteroids has made it a frequent subject of pricing scrutiny.
No — this is a research and educational reference, not dosing guidance.
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