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Investigational Small Molecule

Tesofensine

NS2330 • Oral Triple Monoamine Reuptake Inhibitor

Tesofensine is an oral small molecule, not a peptide. It inhibits serotonin, norepinephrine, and dopamine reuptake. Clinical obesity trials reported weight loss alongside cardiovascular and tolerability concerns.

Routes
Oral capsule
Compound type
Small molecule
Regulatory status
Not FDA approved
Last reviewed
At a glance

Tesofensine Quick Reference

Evidence stage
Human Phase 2
Randomized obesity trial over 24 weeks
Available format
Oral capsule
Once-daily oral dosing studied
Studied dose range
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Research target
Three monoamine transporters
Serotonin, norepinephrine, and dopamine reuptake
Overview

What Is Tesofensine?

Tesofensine (NS2330) is an orally active small molecule that inhibits the reuptake of serotonin, norepinephrine, and dopamine. It was first investigated for neurologic disease, then studied for obesity after weight loss emerged in trials. Despite its place in some peptide catalogs, it is not a peptide.

In a 24-week randomized obesity trial, tesofensine was studied alongside a calorie-restricted diet at 0.25, 0.5, and 1 mg daily. Its long elimination half-life—roughly 10 days—means exposure and adverse effects can build over weeks.

Mechanism

Tesofensine Mechanism of Action

Triple reuptake inhibition

Tesofensine inhibits transporters for serotonin, norepinephrine, and dopamine, increasing signaling through these monoamine pathways.

Appetite and food reward

Central signaling changes are associated with less hunger and food seeking. This differs from the gut-mediated satiety of GLP-1 drugs.

Energy use

Controlled metabolic research reported changes in fat oxidation and nighttime energy expenditure, though reduced intake appears central to the weight-loss effect.

Slow accumulation

Its long half-life and active metabolite can delay steady-state exposure. A dose change may take weeks to show its full effect or tolerability burden.

Research findings

Tesofensine Benefits

The strongest evidence comes from a 24-week randomized obesity trial of 203 participants. The trial report later received an expression of concern, so its estimates warrant caution. Tesofensine has no FDA-approved indication.

Current evidence level: Phase 2 human trial

Weight loss

The 0.5 mg group lost an average 9.2 percentage points more body weight than diet plus placebo over 24 weeks. Trial report.

Appetite control

Its central monoamine activity is associated with reduced hunger and food seeking.

Food reward

Dopamine-pathway activity may help explain why some users describe less persistent food noise; that specific experience is not a clinical endpoint.

Metabolic research

A controlled study reported increased 24-hour fat oxidation and nighttime energy expenditure.

Body composition

Trial analyses found reductions in waist circumference and body fat across studied doses.

Oral administration

Once-daily oral dosing was used in clinical research; no injection or reconstitution is involved.

Protocol planning

Tesofensine Dosing Protocol

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N=1 reports

Tesofensine Community Experience

Self-reported anecdotal experiences aggregated from public & private peptide community discussions and anonymous peptideprotocols.app user reports. This information does not carry the same weight as published research.

Positive reports

  • Less food noise. Users often describe fewer cravings and less persistent food seeking.
  • Weight trend. Some report steady loss over several weeks.
  • Alertness. Better focus and motivation are reported, especially early on.

Negative reports

  • Dry mouth and constipation. Both recur across reports.
  • Heart rate. Palpitations or a higher resting pulse concern some users.
  • Sleep and mood. Insomnia, anxiety, irritability, or low mood can emerge or worsen.
Stacking & synergy

Tesofensine Stacking & Synergy

These are pathway comparisons, not validated combination protocols. Additional appetite suppression or stimulant effects could compound safety concerns.

Tesofensine + Semaglutide

Central appetite effects differ from GLP-1 signaling. Combined use has no established benefit or safety profile and could worsen undereating.

Tesofensine + 5-Amino-1MQ

Different central and cellular mechanisms make this a theoretical pairing. Controlled combination data are absent.

Tesofensine + Retatrutide

A theoretical pairing discussed in fat-loss circles, but no controlled combination data exist. Overlapping appetite suppression could make adequate calorie and protein intake difficult.

Safety notes

Tesofensine Side Effects & Safety

Dry mouth, insomnia, constipation, nausea, headache, and increased heart rate were reported in published trials. Long-term cardiovascular safety remains unresolved.

Its roughly 10-day half-life means adverse effects may build slowly and persist after a dose change.

Common or reported effects

  • Dry mouth, constipation, nausea, and headache.
  • Insomnia or disrupted sleep.
  • Higher resting heart rate or palpitations.

Higher-concern signals

  • Anxiety, irritability, or depressed mood, particularly at higher doses.
  • Cardiovascular tolerability and long-term outcomes are not settled.
  • Product identity and purity can vary outside clinical trials.

The 0.5 mg trial group had a higher heart rate than placebo; higher-dose groups experienced more adverse effects.

Tesofensine Precautions

Major interaction concerns
  • SSRIs, SNRIs, MAOIs, bupropion, tramadol, and other serotonergic medicines.
  • Stimulants that may compound cardiovascular or psychiatric effects.
  • Pregnancy or breastfeeding: safety has not been established.
Conditions needing caution
  • Hypertension, heart disease, arrhythmia, or a high resting pulse.
  • History of mood or anxiety disorders, bipolar disorder, or psychosis.
  • Monitor heart rate, blood pressure, sleep, and mood in any research context.
Regulatory status: Tesofensine is not FDA approved in the United States.
Final verdict

Peptide Protocols Verdict on Tesofensine

Not medical advice. This editorial is our own opinion piece based off the experience of our own lab rats.
Our opinionated opinion

Tesofensine earns attention in fat-loss circles because it can suppress appetite strongly without the gastric-slowing effects associated with GLP-1 drugs. In our experience and community reports, the standout effects are quieter food noise and steady weight loss, sometimes alongside better focus.

The tradeoff is real. Heart-rate, sleep, and mood effects make it more demanding to evaluate than a simple appetite claim suggests, and its long half-life can hide the full impact of a dose change for weeks. We see it as a potent but higher-maintenance research compound, not an automatic first choice.