What is ?

01

What it is

It is a single chain of 29 amino acids, YADAIFTNSYRKVLGQLSARKLLQDIMSR, identical to the start of the 44-amino-acid human hormone. Like the hormone, it ends in an amide (–NH2). Nothing else is changed: no added groups and no substituted amino acids.

The reference record lists the formula C149H246N44O42S and a molecular weight of about 3,358 g/mol (PubChem CID 16132413). Papers also write it as GHRH(1–29) or GRF(1–29), from the hormone’s older name, growth hormone-releasing factor.

Sources: [1] PubChem · reference structure · [2] Science · 1982 · [3] Biochemical and Biophysical Research Communications · 1984

02

Where it came from

Its parent hormone was identified in 1982 in a pancreatic tumor that had caused acromegaly, a condition of excess growth hormone. Roger Guillemin’s group reported the 44-amino-acid sequence and showed that a synthetic copy was fully active.

Chemists then trimmed the chain from its far end. In 1984 rat pituitary-cell experiments, the 1–29 amide kept about half the full hormone’s potency. Shorter fragments still worked, but only at far higher amounts, and at 19 residues activity vanished.

A 1999 review called the 1–29 fragment the shortest synthetic peptide with the full biological activity of GHRH.

Sources: [2] Science · 1982 · [3] Biochemical and Biophysical Research Communications · 1984 · [4] BioDrugs · 1999

03

A template for other analogues

In plasma, an enzyme called dipeptidyl peptidase IV (DPP-IV) cuts GHRH between its second and third amino acids. A 1989 study found the same cut in the 1–29 amide, and that swapping either of the first two amino acids for its mirror-image (D-) form blocked it.

was built on this template: four amino acids substituted, plus, in the 2005 paper that introduced it, a group that binds albumin in the blood, called DAC. The versions with and without DAC are separate compounds.

Its blend with : What is / ?

Sources: [5] Journal of Clinical Investigation · 1989 · [6] Endocrinology · 2005 · [7] Drug Testing and Analysis · 2021

04

vs

The two are often compared. keeps all 44 amino acids and adds a small chemical group to the first; stops at 29.

Side by side: vs , compared. Full profile: What is ?

Sources: [2] Science · 1982

05

What researchers have studied

Its literature runs from 1980s peptide chemistry to modern drug testing:

• How chain length changes growth hormone release from rat pituitary cells.
• Clinical studies of pituitary growth hormone release, reviewed in 1999.
• Anti-doping detection of four GHRH analogues and their breakdown products in urine, including this peptide minus its first two amino acids (2021).

These are observations in laboratory models. They are not evidence about any use in people.

Sources: [3] Biochemical and Biophysical Research Communications · 1984 · [4] BioDrugs · 1999 · [7] Drug Testing and Analysis · 2021

06

How it is supplied and stored

ships as a lyophilized (freeze-dried) powder in 10 mg vials. The powder is stable at room temperature in transit. For lab use it is reconstituted with bacteriostatic water such as .

Concentration is content divided by volume: 10 mg in 2 mL gives 5 mg per mL. The reconstitution calculator handles other combinations.

For storage before and after reconstitution, see how to store lyophilized peptides.

07

How to verify a batch

Every lot has its own certificate of analysis from an independent lab. Read three results separately:

• Identity: confirms the expected compound was detected.
• Purity: the share of the measured material that is the intended compound.
• Content: the amount measured, compared with the label.

Then match the lot number on your vial or bottle to the report, and use the report’s verification link to confirm it with the testing lab. Step by step: how to read a peptide COA.