# GHRH analogues: lipid and glucose findings

> The metabolic account — Philadelphia Anti Aging — Philadelphia Anti Aging follows glucose tolerance, temporary lipid changes and unchanged body weight in GHRH-analogue studies alongside the cognition question.

A proposed benefit for the mind would still have to answer for its effects elsewhere. The GHRH studies offer some specific entries in that account.

## Blood lipids during Nle27-GHRH treatment

An [experiment in age-advanced men and women](https://pubmed.ncbi.nlm.nih.gov/9141536/) used the analogue [Nle27]GHRH-(1-29)-NH2 for 16 weeks. IGF-I and IGFBP-3 rose. Body weight and blood pressure stayed unchanged, as did fasting insulin and glucose. The reported adverse effect was transient hyperlipidemia, a rise in blood lipids, which resolved by the end of the study.

The resolution deserves mention alongside the change. Why did the lipids rise, and would a larger or longer study tell the same story? They affect how persuasive the result seems. The reported change resolved, and these follow-up questions supply no evidence of a lasting injury.

The unchanged body weight also deserves a line of its own. The hormone response in this experiment came with a weight measurement that stayed put. Attaching weight loss to the cognitive argument would misrepresent this unchanged measurement.

## PEG-conjugated GHRH

A [safety and tolerability study of PEG-conjugated GHRH included healthy young men and elderly subjects](https://pubmed.ncbi.nlm.nih.gov/16061831/). GH and IGF-I increased. Reactions at injection sites occurred more frequently than with placebo, though they were mild and transient; no antibodies to GHRH were observed.

Some impairment of glucose tolerance appeared in the elderly subjects with repeated exposure. This was a chemically different GHRH preparation from the one used in the lipid study, and both differ from tesamorelin in the cognition trial.

These reports give the metabolic discussion a subject more concrete than general reassurance. A separate side-effect account for each preparation seems essential to me.

![A laboratory technician positions a rack of unprinted sample tubes beside a chemistry analyzer](images/chemistry-bench.webp)

*An imagined laboratory chemistry bench, illustrating metabolic measurement rather than any named study or treatment.*

## Tesamorelin trial tolerability

The [tesamorelin cognition trial described adverse events as mild](https://pubmed.ncbi.nlm.nih.gov/22869065/). That is the tolerability description belonging to that trial. The [glucose-tolerance observation](https://pubmed.ncbi.nlm.nih.gov/16061831/) and the [temporary lipid change](https://pubmed.ncbi.nlm.nih.gov/9141536/) belong to the other preparations and settings described above.

A future claim about sustained cognitive benefit deserves an equally accessible account of its metabolic consequences. My enthusiasm would depend on both. A broad anti-aging endorsement asks for much more than an interesting mental-performance result and a brief tolerability description.

## The secretagogue editorial

An [editorial in Annals of Internal Medicine questioned whether growth hormone secretagogues were justified for preventing or treating aging](https://pubmed.ncbi.nlm.nih.gov/18981489/). A secretagogue prompts secretion; here the intended secretion is growth hormone.

I take that objection seriously without asking an editorial to decide the later experiments in advance. The question is the proposed use: a particular cognitive investigation can be worth doing while a general program of reversing age-related change remains unpersuasive. The [human trial](/human-cognition) gives the narrower proposition something to discuss.

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Philadelphia Anti Aging brings my objections and enthusiasms to published research on the aging mind; it runs no business and gives no medical advice.