Tesofensine: Appetite Drug Marketed as a 'Peptide' - Evidence, Dose, Legal Status

Key takeaways

• Tesofensine is not a peptide. It is a small synthetic molecule, about 330 daltons with no amino acids, that blocks the reuptake of noradrenaline, dopamine and serotonin. It is sold next to peptides because the same research-chemical sellers, supplement sites and clinics carry it.
• It suppresses appetite, and it works: in a 24-week phase 2 trial of 203 obese adults on a diet, 0.25, 0.5 and 1 mg a day produced 4.5%, 9.2% and 10.6% weight loss against 2.0% on placebo. That trial carries a 2013 Lancet expression of concern, and the 372-patient phase 3 run in Mexico has not been published.
• The price is paid in the heart and the head: heart rate rose about 7 beats per minute at 0.5 mg, blood pressure rose at 1 mg, and insomnia and mood effects were common. The drug stays in the body for weeks, and no trial has counted heart attacks or strokes.
• It is not approved anywhere, Mexico included: the regulator there gave a non-binding favorable opinion in 2023, withheld approval in 2024, and the application was still pending in August 2026. In the US it is unapproved, cannot be compounded, and FDA named it in a December 2025 warning letter.
• If appetite control is the goal, the GLP-1 drugs a clinician can prescribe produce more weight loss, with far larger trials behind them.

Tesofensine at a glance

Also called

NS2330, NS 2330, tesofensine citrate, Tesomet (tesofensine with metoprolol), 'tesofensine peptide' (a misnomer)

Class

Small-molecule triple monoamine reuptake inhibitor (blocks reuptake of noradrenaline, dopamine and serotonin); a phenyltropane of about 330 daltons with no amino acids, not a peptide

Route

Oral tablet once daily in every clinical trial; sold online as capsules

FDA status

Never FDA-approved and not a component of any approved drug. The tesofensine-metoprolol combination (Tesomet) holds orphan designations for Prader-Willi syndrome and hypothalamic obesity, which are not approvals. Not on the 503A bulks list or in any interim category; named in FDA's December 2025 warning letter to an ingredient distributor as ineligible for 503A compounding. Not approved in Mexico either: the application there was still pending in August 2026.

FDA Category 2 (compounding restricted)

No

Available by prescription (US)

Not as a prescription product

Best-studied use

Obesity: a 203-patient phase 2 trial (0.25 to 1 mg daily for 24 weeks) and an unpublished 372-patient company phase 3 in Mexico; earlier Parkinson's and Alzheimer's disease trials, where it failed; hypothalamic obesity in combination with metoprolol

Typical monthly cost (telehealth, 2026)

No legal US product exists; capsules sold online as supplements or research chemicals are not priced here

What tesofensine is, and why it is sold as a 'peptide'

Tesofensine (development code NS2330) is a phenyltropane, a small molecule built on a tropane ring with a dichlorophenyl group attached, and nothing in it is an amino acid (Krug 2026). It inhibits the transporters that clear three monoamines from the gap between nerve cells, noradrenaline, dopamine and serotonin, which makes it a "triple reuptake inhibitor" (Astrup 2008). In people the dominant effect is on appetite: in a two-week study of 32 overweight men told to keep eating normally, it produced 1.8 kg more weight loss than placebo, higher ratings of fullness and satiety, and more fat burned over 24 hours, with no meaningful rise in total energy expenditure (Sjödin 2010).

So why does a search for "tesofensine peptide" return thousands of results? Not chemistry. Tesofensine has never been approved, so the only channels selling it are the research-chemical vendors, supplement websites and "peptide therapy" clinics that also sell BPC-157 and AOD-9604. It inherits their catalogs, their capsules and their vocabulary. An anti-doping laboratory that bought it from an online supplier found it marketed as a dietary supplement for weight management (Krug 2026), and one of the telehealth clinics in our directory lists tesofensine capsules next to its peptides. The label matters for one practical reason: unlike most peptides, tesofensine is fully active by mouth at sub-milligram doses, which means the capsules sold online can do exactly what the trials showed, side effects included.

From Parkinson's drug to diet pill

Tesofensine was developed by the Danish company NeuroSearch, initially with Boehringer Ingelheim, as a treatment for Parkinson's and Alzheimer's disease; it was ineffective for both (Bello 2009). In advanced Parkinson's disease, 14 weeks at 0.125 to 1 mg a day gave modest improvements at two middle doses with no dose-response, while gastrointestinal and neuropsychiatric side effects rose with dose (Rascol 2008).

What the neurology trials did show was weight loss nobody had asked for. Pooling four 14-week trials, 740 patients on tesofensine and 228 on placebo with no diet program, weight changed by +0.5% on placebo and by -0.5%, -0.9%, -1.8% and -2.8% at 0.125, 0.25, 0.5 and 1 mg; heart rate rose by 2 to 7 beats per minute with dose (Astrup 2008b). NeuroSearch redirected the drug to obesity and ran the TIPO-1 trial in Denmark in 2006 and 2007.

The obesity program then stalled twice. In 2013 The Lancet attached an expression of concern to the TIPO-1 paper (Lancet 2013) after a Danish regulatory inspection, and NeuroSearch was winding down (Retraction Watch 2013). The rights moved to Saniona, a Danish biotech, which licensed Mexico and Argentina to the Mexican company Medix. Medix ran a 24-week phase 3 trial of 0.25 and 0.5 mg in 372 adults with obesity and filed for approval with COFEPRIS, Mexico's drug regulator (Saniona 2026). Saniona itself now develops Tesomet, tesofensine combined with the beta-blocker metoprolol, for hypothalamic obesity and Prader-Willi syndrome.

What the evidence actually shows

Tesofensine claims, graded by the evidence behind them

Claim	Grade	What the evidence shows	Sources
Causes substantial weight loss in obese adults	B	One published randomized trial: 203 obese Danish adults on an energy-restricted diet, 24 weeks, 79% completed. Weight loss was 4.5%, 9.2% and 10.6% at 0.25, 0.5 and 1 mg versus 2.0% on placebo. The paper received a Lancet expression of concern in 2013 over trial conduct and adverse-event recording; the authors said the regulator found the efficacy data matched the source records.	Astrup 2008; Lancet 2013; Retraction Watch 2013
Confirmed in a phase 3 trial	C	Company-reported only. Medix's 24-week phase 3 in 372 Mexican adults tested 0.25 and 0.5 mg; Saniona reports about 10% average weight loss at 0.5 mg and more than half of patients losing over 10%, without a placebo figure in the documents we read. Not published in a peer-reviewed journal as of October 2026.	Saniona 2024; Saniona 2026
Works by curbing appetite	B	In 32 overweight men over two weeks, tesofensine increased satiety and fullness, lowered expected food intake and raised fat oxidation by 18 g a day, with no significant change in 24-hour energy expenditure. Small and short, but consistent with the weight-loss trials.	Sjödin 2010
Safe for the heart	C	Not established. Heart rate rose 7.4 beats per minute at 0.5 mg in TIPO-1 and by 2 to 7 beats per minute with dose in the neurology trials; blood pressure rose significantly at 1 mg. The company describes a minor heart-rate rise in phase 3. No trial has measured heart attacks, strokes or deaths; sibutramine, an older reuptake-inhibitor appetite drug, increased nonfatal heart attacks and strokes when it was tested that way.	Astrup 2008; Astrup 2008b; Bello 2009; Saniona 2026; James 2010
Free of psychiatric effects	C	No. Insomnia was among the most common adverse events; neuropsychiatric events rose with dose in Parkinson's disease; the Danish inspection found recurrences of depression, stress and headache were not reliably recorded in TIPO-1; in hypothalamic obesity half of treated patients reported sleep disturbance and one discontinued for worsened anxiety.	Astrup 2008; Rascol 2008; Retraction Watch 2013; Huynh 2022
Treats hypothalamic obesity when combined with metoprolol	B	One small trial: 21 adults, 24 weeks of 0.5 mg tesofensine with 50 mg metoprolol. Placebo-adjusted weight change was -6.3%, with no difference in heart rate or blood pressure, but sleep disturbance (50% vs 13%), dry mouth (43% vs 0%) and headache (36% vs 0%).	Huynh 2022
Treats Parkinson's or Alzheimer's disease	B	Tested and failed. Development for neurodegenerative disease stopped; in advanced Parkinson's, effects were modest with no dose-response and more side effects at higher doses.	Rascol 2008; Bello 2009
Has low abuse potential	B	In 52 recreational stimulant users given single doses, the subjective effects of tesofensine did not differ from placebo and were lower than those of amphetamine, comparable to bupropion or atomoxetine. Single doses only; repeated use was not studied this way.	Schoedel 2010

Two things stand out. First, this is a drug that does what it is sold for. Unlike AOD-9604, which failed its weight-loss trial, or 5-amino-1MQ, which has never been tested in a person, tesofensine has randomized human data showing roughly 9 to 11% weight loss in six months. Second, the record is thinner and dirtier than that number suggests. The only peer-reviewed obesity trial had 203 patients and a regulator's finding that side effects were under-recorded at two of its five sites; the expression of concern is still attached to the paper in PubMed, with no retraction and no correction of the efficacy results (Lancet 2013). The phase 3 exists in press releases and investor reports.

What you are promised versus what is documented

Sales pages call tesofensine a "peptide" that "turns off hunger", promise GLP-1-level results "without injections", describe it as "approved in Mexico" and present it as well tolerated. Sorted by the evidence:

• Documented in humans: dose-related weight loss of about 9 to 11% at 0.5 to 1 mg over 24 weeks with diet; stronger satiety; higher heart rate.
• Company-reported, unpublished: about 10% loss at 0.5 mg in the Mexican phase 3, with a minor heart-rate rise.
• False: that it is a peptide; that it is approved in Mexico or anywhere else; that it is FDA-cleared or legal to compound.
• Unknown: effects beyond about a year of use, cardiovascular outcomes, what happens to weight after stopping, and what is actually in an online capsule.

Tesofensine vs GLP-1 drugs, AOD-9604 and 5-amino-1MQ

The best peptides for weight loss ranking puts these side by side with the rest of the market; the AOD-9604 dosage and 5-amino-1MQ dosage pages do for those compounds what the next section does for tesofensine.

Dosage: what was studied versus what sellers claim

What is unusual here is that the seller doses sit inside the studied range: 500 micrograms is the 0.5 mg the developer chose. That cuts both ways. A capsule that contains what its label says can reproduce the trial weight loss, and the trial heart-rate rise, without the screening, blood-pressure checks and stopping rules the trials had. And dosing has a timing problem trials managed and buyers do not: the half-life is over 200 hours (Krug 2026), so blood levels keep climbing for several weeks after a daily dose is started, and they linger for weeks after it is stopped. "Cycling" on and off every few weeks makes little pharmacological sense for a drug that takes that long to clear.

There is no reconstitution example on this page. Tesofensine is a tablet drug, there is no legal product, and the reconstitution calculator is meant for peptides a pharmacy has dispensed with a labeled concentration.

Side effects and who should not take it

Common in trials. Dry mouth, nausea, constipation, hard stools, diarrhea and insomnia were the most frequent adverse events in TIPO-1 (Astrup 2008). In the hypothalamic obesity trial, half of treated patients reported sleep disturbance, 43% dry mouth and 36% headache (Huynh 2022).

Cardiovascular. Heart rate rises consistently with dose, by 7.4 beats per minute at 0.5 mg after 24 weeks (Astrup 2008), and blood pressure rose significantly at 1 mg (Bello 2009). That is why the Tesomet combination adds metoprolol, a beta-blocker that slows the heart. A few beats per minute sounds small, but the precedent is sobering: sibutramine, which blocks the reuptake of two of the same three monoamines, was tested in nearly 10,000 high-risk patients for an average of 3.4 years and increased nonfatal heart attacks and strokes (James 2010). No comparable outcome trial exists for tesofensine.

Psychiatric. Neuropsychiatric adverse events increased at higher doses in Parkinson's disease (Rascol 2008). The Danish inspection behind the Lancet notice found that recurrences of conditions such as depression, stress and headache had not been reliably recorded, and concluded that the published side-effect profile did not match the actual course of the trial (Retraction Watch 2013). In the Tesomet trial one patient stopped because of worsened pre-existing anxiety (Huynh 2022).

Who should not take it. Nobody can be advised to use an unapproved drug from an unverified source, so the list is categorical: anyone with heart disease, arrhythmia or high blood pressure; anyone with a history of depression, anxiety, bipolar disorder or psychosis; anyone taking antidepressants, stimulants or other drugs that act on serotonin, dopamine or noradrenaline, because combining reuptake inhibitors has never been studied for this drug; anyone pregnant or breastfeeding; and competitive athletes, since WADA lists tesofensine as an S6 stimulant prohibited in competition and it can be detected for weeks (Krug 2026).

Legal status in the United States, and in Mexico

• Not approved by FDA, and not a component of any approved drug. The Tesomet combination holds FDA orphan designations for hypothalamic obesity and Prader-Willi syndrome; a designation is an incentive to develop a drug, not an approval (Saniona 2026).
• Not compoundable. A licensed pharmacy may compound a bulk ingredient only if it has a USP monograph, is a component of an approved drug, or is on FDA's 503A bulks list; the legal tracker explains the three tests. Tesofensine meets none of them. On December 8, 2025, FDA warned a Florida distributor of bulk drug ingredients that tesofensine was among the active ingredients it supplied to pharmacies that are "ineligible for use in human drug compounding" under section 503A, which made those shipments misbranded drugs (FDA warning letter 2025).
• Not in Category 2, and that is not a permission. Tesofensine does not appear on FDA's Category 2 safety list, nor among the withdrawn nominations listed there (FDA Category 2 page). The absence of a safety flag means only that FDA never reviewed it for compounding; it still has no route into a pharmacy.
• Sold anyway. Capsules marketed as supplements or research chemicals are unapproved drugs when sold for weight loss in people; FDA's 2026 warning letters to peptide vendors made clear that a research-use label does not survive a dosing guide. A telehealth prescription does not change this: there is no pharmacy that can lawfully fill it.
• Not approved in Mexico. COFEPRIS's technical committee issued a favorable but non-binding opinion in February 2023 (Saniona 2026). On November 6, 2024, Saniona announced that Medix had not received approval and was entering a dialogue with the agency (Saniona 2024). Saniona's interim report of August 27, 2026 says Medix "continues to pursue regulatory approval" (Saniona 2026). Websites describing tesofensine as approved in Mexico are contradicted by the developer's own filings.

Cost and what a clinician can prescribe instead

There is no legal US price for tesofensine because there is no legal US product. Capsule listings exist online; we do not quote or link to them, because the number buys an unverified powder, not a medication.

If the search behind this page is "an appetite drug that works", the prescribable options in October 2026 are better on both evidence and safety monitoring. Brand GLP-1 drugs cost about $349 a month for Wegovy through the manufacturer's pharmacy and $299 to $449 for Zepbound by dose, with the Wegovy pill at $149 to $299; compounded semaglutide or tirzepatide runs about $150 to $350 a month where a documented individual need allows it. Our cost guide and compounded semaglutide versus tirzepatide guide have the details and the conditions. A clinician prescribing them will also check the heart rate and blood pressure that tesofensine buyers are left to monitor on their own.

Bottom line

Tesofensine is the rare "peptide" that is neither a peptide nor a placebo. It is a monoamine reuptake inhibitor that failed as a Parkinson's drug, produced 9 to 11% weight loss in a 203-patient obesity trial, raised heart rate at every effective dose, and still has no approval anywhere after two decades, including in Mexico, where its own developer reports the application pending. The capsules sold online contain, at best, a real drug at a real dose with none of the medical supervision its trials required.

If you want what tesofensine promises, the GLP-1 drugs deliver more of it, have been tested in far more people, and can be prescribed by a clinician who will watch your heart while you take them.

Frequently asked questions

+−Is tesofensine a peptide?

No. Tesofensine is a small synthetic molecule of about 330 daltons, a phenyltropane with no amino acids, which anti-doping rules classify as a stimulant. It blocks the reuptake of three brain chemicals, noradrenaline, dopamine and serotonin. It is called a peptide online only because the vendors and clinics that sell research peptides also sell it, often in the same catalog and with the same weight-loss language.

+−What is tesofensine?

An appetite-suppressing drug that was first developed in Denmark in the early 2000s for Parkinson's and Alzheimer's disease. It did not help either condition, but patients lost weight, so it was redeveloped for obesity. In a 24-week trial it produced 9 to 11% weight loss at 0.5 to 1 mg a day, with higher heart rate as the main cost. It has never been approved anywhere.

+−How much weight can you lose on tesofensine?

In the only published obesity trial, 203 adults on a calorie-restricted diet lost 4.5%, 9.2% and 10.6% of body weight over 24 weeks at 0.25, 0.5 and 1 mg a day, against 2.0% on diet and placebo. A larger company trial in Mexico reported about 10% at 0.5 mg but has not been published. The published trial carries a Lancet expression of concern because side effects were not reliably recorded at two of its sites.

+−What is the tesofensine dose?

There is no approved dose. The obesity trials tested 0.25, 0.5 and 1 mg by mouth once a day for 24 weeks, and the developer chose 0.5 mg as the dose to take forward. Because the drug has a half-life of more than 200 hours, it takes weeks to reach a steady level and weeks to leave the body. Online capsules are usually labeled 250 to 500 micrograms; one tested by an anti-doping lab held 483 micrograms against a 500 microgram label.

+−What are the side effects of tesofensine?

In trials the most common were dry mouth, nausea, constipation, diarrhea and insomnia. Heart rate rose by about 7 beats per minute at 0.5 mg, and blood pressure rose at 1 mg. Sleep problems, anxiety and mood changes were reported, and a Danish inspection found that recurrences of depression, stress and headache were not reliably recorded in the pivotal trial. No study has measured heart attacks or strokes.

+−Is tesofensine FDA approved or approved in Mexico?

Neither. FDA has never approved it, and FDA named it in a December 2025 warning letter as ineligible for pharmacy compounding. In Mexico, the regulator COFEPRIS gave a favorable non-binding technical opinion in February 2023 but did not grant approval in November 2024, and the developer's August 2026 report says its partner is still pursuing approval. Claims that it is approved in Mexico are not supported by the company's own filings.

+−Can you buy tesofensine capsules legally, and what does it cost?

There is no legal US source. It is not approved, no licensed pharmacy may compound it, and capsules sold online as supplements or research chemicals have no verified content. We do not quote or link to those prices. If weight loss is the goal, brand GLP-1 pens cost about $299 to $449 a month for cash buyers in 2026 and come with a prescriber and a label.

+−Is tesofensine banned in sports?

Yes, in competition. The World Anti-Doping Agency lists it among S6 stimulants, prohibited in competition only. Because of its long half-life, anti-doping researchers detected it in urine for up to about 500 hours after a single 483 microgram capsule, so athletes should assume a dose taken weeks before an event can still be found.

+−Tesofensine vs semaglutide: which is better?

Semaglutide and tirzepatide have large phase 3 trials, produce about 15 to 21% weight loss and are approved and prescribable. Tesofensine has one published 203-patient obesity trial with an expression of concern, an unpublished company phase 3 and a heart-rate signal, and it cannot legally be prescribed in the US. On evidence and law the GLP-1 drugs win.

Sources

1. StudyAstrup A, Madsbad S, Breum L, Jensen TJ, Kroustrup JP, Larsen TM. Effect of tesofensine on bodyweight loss, body composition, and quality of life in obese patients: a randomised, double-blind, placebo-controlled trial (TIPO-1). Lancet 2008;372:1906-13. (2008)
2. SourceThe Lancet. Expression of concern: Effect of tesofensine on bodyweight loss, body composition, and quality of life in obese patients. Lancet 2013;381:1167. (2013)
3. NewsOransky I. Trial irregularities earn Lancet study of potential weight loss drug tesofensine Expression of Concern. Retraction Watch, April 9, 2013. (2013)
4. StudyAstrup A, Meier DH, Mikkelsen BO, Villumsen JS, Larsen TM. Weight loss produced by tesofensine in patients with Parkinson's or Alzheimer's disease. Obesity 2008;16:1363-9. (2008)
5. StudyRascol O et al. Tesofensine (NS 2330), a monoamine reuptake inhibitor, in patients with advanced Parkinson disease and motor fluctuations: the ADVANS study. Arch Neurol 2008;65:577-83. (2008)
6. StudySjödin A et al. The effect of the triple monoamine reuptake inhibitor tesofensine on energy metabolism and appetite in overweight and moderately obese men. Int J Obes 2010;34:1634-43. (2010)
7. ReviewBello NT, Zahner MR. Tesofensine, a monoamine reuptake inhibitor for the treatment of obesity. Curr Opin Investig Drugs 2009;10:1105-16. (2009)
8. StudySchoedel KA, Meier D, Chakraborty B, Manniche PM, Sellers EM. Subjective and objective effects of the novel triple reuptake inhibitor tesofensine in recreational stimulant users. Clin Pharmacol Ther 2010;88:69-78. (2010)
9. StudyHuynh K et al. Randomized controlled trial of Tesomet for weight loss in hypothalamic obesity. Eur J Endocrinol 2022;186:687-700. (2022)
10. StudyJames WP et al. Effect of sibutramine on cardiovascular outcomes in overweight and obese subjects (SCOUT). N Engl J Med 2010;363:905-17. (2010)
11. StudyKrug O, Thomas A, Thevis M. Investigations into the metabolism and elimination of tesofensine in human urine. Drug Test Anal 2026;18:1163-73. (2026)
12. NewsSaniona AB. Mexican application for tesofensine not yet approved (Medix did not receive COFEPRIS approval; phase 3 of 372 patients). Press release, November 6, 2024. (2024)
13. SourceSaniona AB. Interim report January to June 2026 (tesofensine status in Mexico, Medix phase 3 summary, Tesomet orphan designations and phase 2 results). August 27, 2026. (2026)
14. RegulatoryFDA. Warning letter 320-26-24 to Darmerica, LLC (active pharmaceutical ingredient distributor, Davie, Florida), December 8, 2025: tesofensine listed among APIs distributed to pharmacies that are ineligible for compounding under section 503A. (2025)
15. RegulatoryFDA. Certain bulk drug substances for use in compounding that may present significant safety risks (Category 2 list; content current as of April 22, 2026). (2026)