Tesofensine

Tesofensine is worth flagging as a small molecule, not a peptide — it works on brain chemistry rather than hormone receptors. It blocks the reuptake of three neurotransmitters: serotonin, noradrenaline, and dopamine.

By preventing their reabsorption it raises the levels of these signals at the synapse, and the net effect is appetite suppression. The mechanism is essentially stimulant-like, which is both its strength (notable weight loss in trials) and its liability.

Those liabilities are real: it raises heart rate, can affect blood pressure and mood, and remains investigational. Importantly, a pivotal phase-2 trial later received a formal Expression of Concern from The Lancet over conduct irregularities at trial sites — a reason to read its results cautiously.