Tesofensine

Tesofensine is an oral tablet first developed for Parkinson's and Alzheimer's disease that has shown weight loss effects.

It works in the brain by blocking the reuptake of three signaling chemicals: dopamine, norepinephrine, and serotonin, leading to lower appetite and increased resting energy use. [Source: Peptide Dosing Protocols]

Tesofensine increases the brain levels of three signaling chemicals at the same time: dopamine, norepinephrine, and serotonin. It does this by blocking the transporters that normally pull these chemicals back into the cell after they are released. With less reuptake, more signal stays in the synapse — the small gap between two brain cells.

The drug was first studied for Parkinson's and Alzheimer's disease because dopamine signaling matters in both. The neurological results were weaker than the developer hoped. The unexpected finding was weight loss. Patients lost weight in a dose-dependent way without anyone telling them to diet. That observation moved the program into obesity.

In animal and human studies, two effects show up. The first is reduced appetite, driven by higher dopamine and norepinephrine signaling in the hypothalamus, the part of the brain that helps regulate hunger. The second is a small rise in resting energy use, driven by higher norepinephrine signaling in peripheral tissues. Together these create the calorie gap that pushes weight down.

Half-life is the time it takes for half of a dose to leave the body. For tesofensine that is about 9 days. Most drugs have half-lives measured in hours. A 9-day half-life means each daily tablet adds onto what is still in the body from prior days. Levels keep rising for about 4-6 weeks before they level off.

The main mechanism is that it inhibits the reuptake of dopamine, norepinephrine, and serotonin in the brain (a triple monoamine reuptake inhibitor, or SNDRI). Tesofensine is metabolized by CYP3A4 to a single metabolite (M1, or NS2360). M1 has a longer half-life — about 16 days — but contributes a smaller share of the overall pharmacologic effect. It acts in the central nervous system, with downstream effects on appetite regulation and resting energy expenditure. It is not a GLP-1 like semaglutide or tirzepatide and is not a stimulant in the amphetamine sense, though norepinephrine signaling overlaps. [Source: Peptide Dosing Protocols]

Provider notes: [PDP compound] tesofensine