# GHRH and diagnostic stimulation

> GHRH testing and diagnosis | CJC-1295 MD — CJC-1295 MD explores the older GHRH-plus-arginine test, the move to other GH stimulation tests, and the purpose of a provoked hormone response.

**Diagnosis**

The older diagnostic literature gives a hormone rise a very specific job. Its tightly defined purpose appeals to me.

## GHRH plus arginine

Native GHRH combined with intravenous arginine was once a principal alternative to the insulin tolerance test for investigating adult growth hormone deficiency. The [Endotext account of stimulation testing](https://www.ncbi.nlm.nih.gov/books/NBK395585/) reports sensitivity around 95% and specificity around 91% for that historical test. These figures describe diagnostic performance in that setting. They say nothing about the benefits of taking CJC-1295.

A provocation test deliberately asks a gland to respond. I like the limited ambition of that exercise: the response helps answer an existing question about function. CJC-1295's long-acting design belongs to a separate development history, and the diagnostic work described here used native GHRH.

## After native GHRH became unavailable

The native-GHRH diagnostic product was discontinued in the United States in November 2008. The [history of GH stimulation testing](https://www.ncbi.nlm.nih.gov/books/NBK395585/) describes the subsequent use of glucagon stimulation and, later, oral macimorelin. The [macimorelin validation study](https://pubmed.ncbi.nlm.nih.gov/23559086/) examined a different agent as an oral test for adult GH deficiency.

This is an unusually instructive turn in the story. Work on stimulating GH found a useful direction in diagnosis, while CJC-1295's therapeutic programme stalled. I expected clever albumin chemistry to dominate this story. The diagnostic history suggested a more practical measure of usefulness: how well a response answers the question being asked.

![Students gathered around a brain model in a sunlit teaching room](images/pituitary-seminar.webp)

*An imagined teaching seminar about the pituitary, rather than a scene from a particular study.*

## A prolonged hormone response

CJC-1295's [healthy-adult pharmacology study](https://pubmed.ncbi.nlm.nih.gov/16352683/) documented prolonged GH and IGF-1 increases. In another study of healthy men, [GH retained its pulsatile pattern](https://pubmed.ncbi.nlm.nih.gov/17018654/) during sustained stimulation. That rhythm matters to the description of the drug's action. The participants' health and the outcomes measured matter just as much to any proposed clinical interpretation.

I hesitate over converting a successful provocation into a treatment goal. The clinical record establishes activity. A defined therapeutic purpose still requires evidence of benefit and acceptable risk in the relevant population. The [research page](/research) follows the attempt to pursue one such purpose in HIV-associated visceral obesity.

## Questions for a medical discussion

My list for a medical conversation is fairly ordinary. What condition is being investigated? What does the test result contribute to that investigation? Which outcome would count as a useful treatment effect? How would adverse effects alter the decision?

Those questions require an individual clinical assessment. This site cannot interpret a personal hormone result or determine whether a treatment is appropriate. For the study quantities and exposure measurements, there is a separate [research-dose page](/dosage).

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