GH-Axis Research

Result. Reported reduction in visceral adipose tissue versus placebo, with attenuation of the effect after discontinuation.

Adverse events. Injection-site reactions, arthralgia, peripheral oedema; effects on glucose parameters were monitored.

Limitations. Population is specific to HIV-associated lipodystrophy. Findings should not be extrapolated to other populations, and the effect reversed after stopping.

Result. Reported increases in growth velocity in the paediatric deficiency population.

Adverse events. Injection-site reactions, flushing, headache.

Limitations. The evidence base is a paediatric deficiency population and a diagnostic application. It does not support extrapolation to adults without deficiency.

Result. Sustained elevation of GH and IGF-1 concentrations was reported following administration in early-phase human work.

Adverse events. Injection-site reactions and flushing reported in early-phase work.

Limitations. Early-phase pharmacodynamic work only. No outcome trials. The DAC and non-DAC forms differ materially and are frequently conflated in non-scientific sources.

Result. 25.3 hours versus 32.6 hours for placebo. The difference was not statistically significant (p=0.15).

Adverse events. No significant safety signal over the short treatment period.

Limitations. This is the only human randomised trial of ipamorelin at any dose, it is a negative result, and the amount used, about 2 mg per administration intravenously for a 70 kg adult, is roughly ten times what is sold for subcutaneous use.

Result. Reported to release growth hormone with greater selectivity than earlier secretagogues in the models studied.

Adverse events. Not established in sustained human use.

Limitations. A pharmacodynamic signal is not a clinical outcome. No adequate long-term human outcome or safety data.

Result. Concludes that no clinical data support the use of GHK-Cu for musculoskeletal conditions, that CJC-1295 and ipamorelin synergy data is murine only, that tesamorelin has no supporting orthopaedic evidence, and that for the class generally the indications, amounts, frequency and duration of treatment remain unknown.

Adverse events. Not an outcome of the review.

Limitations. A narrative review, not a meta-analysis. It is catalogued because it is the most recent peer-reviewed statement of how thin this evidence base is, and because it is the counterweight to every vendor page that implies otherwise.