Tesofensine (NS2330)

Tesofensine (development code NS2330) is a small-molecule triple monoamine reuptake inhibitor — meaning it blocks the reuptake of serotonin, norepinephrine, and dopamine simultaneously, raising synaptic levels of all three monoamines. It was originally developed by NeuroSearch as a candidate for Parkinson's disease and Alzheimer's disease, both based on the dopaminergic and noradrenergic actions. The compound failed those initial indications but was noted to produce significant weight loss in trial participants, which redirected its development toward obesity.^[1]

Important framing: tesofensine is not a peptide. It is widely discussed in peptide research and biohacking communities as an alternative or adjunct to GLP-1 weight-loss medications, which is why it's covered on this site, but the molecule itself is a small organic compound. The "peptide community" classification is functional (where the discussion happens) rather than chemical.

Tesofensine blocks the synaptic reuptake of three monoamine neurotransmitters:

• Serotonin — affects appetite regulation through hypothalamic and other CNS pathways; serotonergic effects contribute to satiety signaling.
• Norepinephrine — provides sympathetic activation, contributing to thermogenesis, reduced appetite, and the stimulant-like subjective effects.
• Dopamine — affects reward processing and may reduce food-cue-driven eating; also contributes to subjective energy and mood effects.

The net pharmacological effect is appetite suppression through central rather than peripheral mechanisms — a fundamentally different approach from the peripheral incretin biology of GLP-1 medications. Where GLP-1s slow gastric emptying and signal satiety through gut-derived hormone signaling, tesofensine reduces the central drive to eat through monoamine-mediated changes in appetite circuits.

The monoamine-trio profile also explains the side-effect pattern: stimulant-class effects (increased heart rate, blood pressure, anxiety, insomnia) are dose-dependent and consistent with the noradrenergic and dopaminergic actions.

The peer-reviewed literature on Tesofensine is summarized below across two tiers: human research (the highest standard), and preclinical / emerging research (animal models and early-stage human work).

This table summarizes commonly discussed claims and how the published evidence weighs in. The aim is clarity — supported claims, claims that look promising but need more data, and claims that outrun the science.

The community-standard tesofensine protocol that has emerged through 2022-2026 is:

• Dose: 0.5 mg orally, once daily, taken in the morning
• Cycle pattern: 8 weeks on, 4 weeks off
• Timing: morning administration to minimize insomnia interference; with or without food
• Cardiovascular monitoring: baseline and periodic blood pressure and heart rate checks

The 0.5 mg dose is the same as that used in the Astrup 2008 trial — the dose that produced ~9% weight loss with manageable tolerability. The 1.0 mg dose produces somewhat greater weight loss but with substantially worse cardiovascular and CNS side effects, and is generally not recommended outside clinical trial contexts.

The Mexican Tesomet product combines tesofensine 0.5 mg with metoprolol succinate (typically 50-100 mg) to manage cardiovascular side effects. This combination represents the most-validated tesofensine use pattern from a clinical-development standpoint.

The 8-on/4-off cycling pattern reflects the community observation that efficacy declines at weeks 4-6 and that prolonged use produces tolerance and worse side-effect tolerability. The break period appears to restore much of the initial efficacy.

Tesofensine is one of the few non-incretin weight-loss interventions with substantive Phase 2 trial data behind it. The 9-11% weight loss in the Astrup 2008 trial is genuinely meaningful — comparable to liraglutide and only modestly behind early semaglutide doses. The mechanism is fundamentally different from GLP-1s (central monoamine vs peripheral incretin), making it a real alternative or potential adjunct for users who don't respond well to GLP-1s.

The drawbacks are also real: stimulant-class cardiovascular and CNS side effects, real serotonin syndrome risk if combined with serotonergic medications, tolerance development requiring cycling, and lack of FDA approval limiting availability through standard medical channels. For users committed to weight-loss intervention and finding GLP-1s unsuitable or inadequate, tesofensine is a defensible bet within community protocols; for users who have GLP-1 access and tolerability, the case for switching is weaker. See our tesofensine vs semaglutide comparison for the decision framework.