Tesofensine

Weight Loss / CNS Compound (Triple Reuptake Inhibitor)investigational

Also known as: NS2330, TE

A triple monoamine reuptake inhibitor (serotonin, norepinephrine, dopamine) originally developed for Parkinson's and Alzheimer's disease, repurposed as a potent weight-loss agent.

Overview

Tesofensine is a small-molecule triple monoamine reuptake inhibitor that blocks the reuptake of serotonin, norepinephrine, and dopamine. Originally developed by NeuroSearch for neurodegenerative diseases (Parkinson's and Alzheimer's), it was unexpectedly found to produce significant weight loss in clinical trials โ€” patients lost substantially more weight than with any approved anti-obesity drug at the time. This led to its repurposing as an anti-obesity compound. In a Phase II trial, tesofensine 0.5mg produced an average weight loss of 12.8 kg over 24 weeks, far exceeding results seen with sibutramine or other available agents. It reduces appetite through central appetite suppression and increases resting energy expenditure via sympathetic activation. While technically not a peptide, tesofensine is commonly included in peptide clinic weight-loss protocols. It is currently in Phase III trials in several countries and has regulatory approval in some markets (Mexico as Tesomet in combination with metoprolol).

Mechanism of Action

Tesofensine acts on central monoamine systems: (1) Inhibits reuptake of serotonin (5-HT), reducing appetite and increasing satiety signaling; (2) Inhibits norepinephrine reuptake, increasing sympathetic tone and resting energy expenditure; (3) Inhibits dopamine reuptake, enhancing reward signaling and reducing food-seeking behavior; (4) Increases thermogenesis through elevated catecholamine activity; (5) Reduces overall caloric intake by 26-32% without formal dietary restriction; (6) Has a long half-life (~9 days) allowing once-daily dosing.

Molecular Formula

C17H23NO3

Molecular Weight

289.37 g/mol

Sequence

N/A โ€” small molecule, not a peptide

Dosage Protocols

Dose Range

0.25mg โ€“ 0.5mg

Frequency

Once daily

Route

oral

Cycle Length

12-24 weeks

Start at 0.25mg and titrate to 0.5mg after 1-2 weeks. Take in the morning to avoid sleep disruption. 1.0mg was tested but caused unacceptable cardiovascular effects. Long half-life (~9 days) means steady state takes weeks. Often combined with beta-blocker (metoprolol) to mitigate heart rate increase.

Source: Phase II clinical trial protocols

Side Effects

EffectSeverity
Increased heart ratemoderate
Dry mouthmild
Insomniamild
Constipationmild
Elevated blood pressuremoderate
Mood changesmoderate

Pros & Cons

โœ“

Produced the largest weight loss of any drug in Phase II trials at the time โ€” 12.8 kg average in 24 weeks

โœ“

Oral administration with once-daily dosing due to long half-life

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Dual mechanism: reduces appetite AND increases energy expenditure

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Potential cognitive/mood benefits from dopamine reuptake inhibition

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Cardiovascular side effects (heart rate, blood pressure) require monitoring and possible beta-blocker co-therapy

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Not yet FDA-approved โ€” limited availability in most countries

โœ—

CNS-active compound with potential for mood changes and sleep disruption

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Long half-life means side effects persist for days if they occur

Research Studies

Legal Status

Not FDA-approved. Phase III clinical trials ongoing. Approved in Mexico as part of Tesomet (tesofensine + metoprolol). Available from some compounding pharmacies and research chemical suppliers. Prescription-only where approved.

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