In the mid-1990s, antiretroviral therapy was transforming HIV from a death sentence into a chronic condition — and creating an unexpected syndrome in its wake. Patients on the new combinations were developing visceral fat accumulation, peripheral fat loss, dyslipidaemia, and a measurably blunted growth hormone rhythm. A small Canadian biotech in Montréal saw the lever. Native GHRH had a half-life of seven minutes, cleaved almost instantly by an enzyme called DPP-IV. Their structural innovation — adding a single trans-3-hexenoic acid group to the N-terminus — blocked the cleavage site, extended the half-life to twenty-six minutes, and made an entire pharmacology clinically viable.

That compound is Tesamorelin, and in 2010 it became one of the very few synthetic peptides ever to clear the full FDA approval pathway.

In this episode, Dr.  ...