Somatropin (recombinant human GH)

The verdict

Our read at a glance.

Whether body composition changes in GH-deficient adults justify giving growth hormone to people whose own production is normal.

The signal

The approved evidence is substantial and specific: growth hormone deficiency in children and adults, Turner syndrome, small for gestational age, Prader-Willi syndrome, short bowel syndrome and HIV-associated wasting, supported by labelled products and a long trial literature. In adults with genuine deficiency, replacement reduces fat mass, increases lean mass and improves quality-of-life measures. The anti-ageing extrapolation traces back to a small 1990 study in men over sixty, whose body-composition findings were widely reported and whose author and journal later publicly cautioned against the use being made of them. Subsequent systematic review of growth hormone in the healthy elderly found small changes in body composition alongside high rates of adverse effects, and did not support the anti-ageing claim.

The unknown

Long-term consequences of raising IGF-1 in people who are not deficient, where the epidemiology linking higher IGF-1 to certain cancers is the specific concern that has never been resolved prospectively.

Our read

The honest anchor for a whole category. It works in deficiency, it measurably changes body composition, and the trade in it for ageing is not a regulatory grey area - it is the one thing on this Watchlist that Congress wrote a specific criminal provision about. Anyone reasoning from secretagogues to benefits should be clear that the benefits belong to this molecule, in people who lack it.