Summary
Tesofensine is an oral small molecule, not a peptide, that blocks reuptake of serotonin, noradrenaline, and dopamine and was first studied for Parkinson and Alzheimer disease before weight loss was noticed. In a 24 week randomized trial of 203 obese adults, 0.5 mg daily produced 9.2% and 1.0 mg 10.6% placebo adjusted weight loss, with dose related increases in heart rate and blood pressure. It has not been approved by FDA and appears on peptide sellers' lists only because it is marketed alongside them.
What is Tesofensine?
Tesofensine is an oral small molecule triple monoamine (serotonin, noradrenaline, dopamine) reuptake inhibitor; not a peptide. It is also known as NS 2330, NS-2330, Tesofensine citrate.
How does it work?
Tesofensine inhibits the presynaptic transporters for serotonin, noradrenaline, and dopamine, raising synaptic levels of all three. The appetite suppression is attributed mainly to noradrenergic and dopaminergic effects on hypothalamic feeding circuits, with a smaller contribution from increased energy expenditure. It has an active metabolite and a long half life of several days.
| Cluster | Metabolic and growth hormone axis |
|---|---|
| Routes | Oral tablet or capsule, once daily |
| Conditions studied | Obesity and chronic weight management; Fat loss and body composition |
| Record | v3, draft, verified Sep 22, 2026 |
What does the evidence say about Tesofensine?
One well conducted phase 2 randomized controlled trial in obesity (Astrup 2008, n = 203, 24 weeks) showed mean weight loss of 6.7 kg (0.25 mg), 11.3 kg (0.5 mg), and 12.8 kg (1.0 mg) versus 2.2 kg with placebo and diet, equal to placebo adjusted losses of 4.5%, 9.2%, and 10.6%. Dry mouth, nausea, constipation, insomnia, and a heart rate increase of about 7 beats per minute at the top dose were seen, with blood pressure rises at 1.0 mg. No completed US phase 3 program has been published in the indexed literature.
| Evidence type | Indexed studies | Participants (human) |
|---|---|---|
| Human randomized trials | 2 | 203 |
| Human observational studies | 0 | n/a |
| Animal studies | 0 | n/a |
| All indexed studies | 2 | 203 |
Human evidence
Astrup 2008 (Lancet): 203 obese adults (BMI 30 to 40) randomized to placebo or tesofensine 0.25, 0.5, or 1.0 mg daily with a hypocaloric diet for 24 weeks. Weight loss was 2.2 kg, 6.7 kg, 11.3 kg, and 12.8 kg respectively; the 0.5 mg dose achieved most of the benefit with fewer cardiovascular effects. Adverse events were dry mouth, nausea, constipation, hard stools, diarrhea, and insomnia; heart rate rose by 7.4 beats per minute at 1.0 mg and blood pressure increased at that dose. Earlier trials in Parkinson and Alzheimer disease found no meaningful benefit for those conditions but recorded weight loss as a side effect. Doggrell 2009 reviews the trial and the cardiovascular concerns that shaped later development.
Animal evidence
Rodent studies showed reduced food intake and body weight through monoamine reuptake inhibition, consistent with the human findings. Animal data are supportive rather than the primary evidence base.
Key studies
| Study | Design and population | Outcome | Grade |
|---|---|---|---|
| Effect of tesofensine on bodyweight loss, body composition, and quality of life in obese patients: a randomised, double-blind, placebo-controlled trial2008 PMID 18950853 | Randomized, double blind, placebo controlled phase 2 trial, 24 weeksn = 203 Obese adults (BMI 30 to 40) on a hypocaloric diet | Weight loss 6.7 kg (0.25 mg), 11.3 kg (0.5 mg), 12.8 kg (1.0 mg) versus 2.2 kg placebo; dose related heart rate and blood pressure increases | Evidence: Human RCT evidence |
| Tesofensine, a novel potent weight loss medicine. Evaluation of Astrup A et al. Lancet 20082009 PMID 19548858 | Expert evaluation of the phase 2 trialObese adults from the 2008 trial | Confirms roughly twice the weight loss of existing oral agents and highlights cardiovascular safety questions for phase 3 | Evidence: Human RCT evidence |
Conditions studied
| Condition | Grade | Note |
|---|---|---|
| Obesity and chronic weight management | Not graded | GLP-1 based peptides are the only peptides with large randomized trials for weight loss. Semaglutide 2.4 mg produced 14.9% mean weight loss over 68 weeks and tirzepatide 15 mg produced 20.9% over 72 weeks. Retatrutide, cagrilintide, and survodutide are in late stage trials. |
| Fat loss and body composition | Evidence: Human RCT evidence | Phase 2 weight loss of 6.7 to 12.8 kg versus 2.2 kg on placebo over 24 weeks, with dose related heart rate and blood pressure increases; a small molecule, not approved. |
Is Tesofensine legal in the United States?
FDA and compounding status
Not FDA approved and not on any FDA compounding list as of the pages current to April 2026. It is a synthetic small molecule with no US marketing authorization and no 503A nomination, so there is no lawful basis for a US compounding pharmacy to dispense it. Some products sold online as tesofensine are unverified imports or research chemicals.
WADA status
WADA status unclear. The current prohibited list does not name this compound explicitly and its class status is not settled. Athletes should ask their anti-doping organization before use.
Regulatory timeline
No regulatory events recorded.
What published studies of Tesofensine used
Ranges below are reported from published studies and labeling only. PeptideAgent does not recommend doses or protocols.
Phase 2 trial doses: 0.25 mg, 0.5 mg, or 1.0 mg orally once daily for 24 weeks (Astrup 2008). The 0.5 mg dose was identified as the best balance of efficacy and tolerability. These are trial doses for an unapproved drug, not a recommendation.
Routes reported
| # | Route |
|---|---|
| 1 | Oral tablet or capsule, once daily |
What are the side effects and interactions of Tesofensine?
Side effects
| # | Reported side effect |
|---|---|
| 1 | Dry mouth (most common) |
| 2 | Nausea, constipation, and hard stools |
| 3 | Insomnia and mood changes |
| 4 | Increased heart rate (about 7 beats per minute at 1.0 mg) |
| 5 | Increased blood pressure at the 1.0 mg dose |
| 6 | Dizziness and headache |
| 7 | Long term cardiovascular safety not established |
Interactions
| # | Interaction |
|---|---|
| 1 | Monoamine oxidase inhibitors and serotonergic antidepressants: theoretical risk of serotonin syndrome and hypertensive effects |
| 2 | Stimulants and sympathomimetics: additive heart rate and blood pressure effects |
| 3 | Antihypertensives: may need adjustment because of pressor effects |
| 4 | No formal human drug interaction studies published |
Contraindications
| # | Contraindication |
|---|---|
| 1 | Uncontrolled hypertension or cardiovascular disease |
| 2 | Concurrent MAO inhibitor use |
| 3 | Pregnancy and breastfeeding (no data) |
| 4 | History of psychiatric illness or substance use disorder (dopaminergic drug, limited data) |
How do people access Tesofensine legally?
Typical cost: Not available through licensed US channels. Products sold as research chemicals are not lawful for human use and are not verified for identity or purity.
Verified access options
Step 1
No lawful United States access path identified on the last verified date outside a registered clinical trial.
Step 2
Not available as an FDA approved product and not eligible for compounding under section 503A or 503B.
Step 3
Products labeled research use only are not lawful for human use and are not verified for identity or purity.
Access paths are verified against public regulatory records and prescriber licensing. We never list unlicensed vendors.
Compare Tesofensine
What's actually offered, and what that means for you
Licensed compounding pharmacies, clinics, and telehealth prescribers openly offer many unapproved peptides, and prescribers write prescriptions for them. That does not make tesofensine lawful. Tesofensine is not FDA approved and not on the 503A bulks list, so a pharmacy has no lawful basis to compound it. [3] [4]
Enforcement is uneven. FDA mostly acts through warning letters to compounders and online sellers, Category 2 safety listings, and import alerts that let it detain shipments, rather than stopping every pharmacy. State pharmacy boards oversee pharmacies day to day, and their rules differ. [4] [6] [7] [8] [9]
What changes for you
- No FDA review of the product: FDA does not check a compounded drug's safety, effectiveness, or quality before it is sold. [9]
- Identity, purity, sterility, and dose accuracy can vary from batch to batch. [4]
- Insurance rarely covers it, so you usually pay cash.
- For tested athletes, WADA status is unclear; ask your anti-doping organization before any use. [5]
What to check
These checks lower some risks, but they do not make an unlawfully compounded product lawful or safe. Check for:
- A 503A pharmacy licensed in your state (your state board of pharmacy publishes license lookups). [9]
- A real evaluation by a licensed prescriber, not just an online form.
- A certificate of analysis for the specific batch.
Frequently asked questions
Is tesofensine legal in the United States?
It is not FDA approved and is not on any FDA compounding list, so no US pharmacy can lawfully dispense it. Products sold online are unapproved drugs of unverified origin. PeptideAgent has not verified approval status in any other country. [3] [4]
Does tesofensine work for weight loss?
In the one published phase 2 randomized trial, yes: 203 obese adults lost a mean 11.3 kg on 0.5 mg and 12.8 kg on 1.0 mg over 24 weeks versus 2.2 kg on placebo, about 9 to 11% placebo adjusted. That is roughly double the effect of older oral anti-obesity drugs and in the range of semaglutide at 6 months, but it comes from a single 24 week study without a published phase 3 confirmation or long term safety data. [1] [2]
What are the side effects of tesofensine?
Dry mouth, nausea, constipation, insomnia, and dizziness were the common effects in the phase 2 trial. The important concern is cardiovascular: heart rate rose by about 7 beats per minute and blood pressure increased at the 1.0 mg dose, which is why the 0.5 mg dose was favored. Long term safety has not been established. [1]
How is tesofensine taken?
As a once daily oral tablet or capsule. The phase 2 trial tested 0.25, 0.5, and 1.0 mg daily for 24 weeks alongside a reduced calorie diet. These are trial doses for a drug that has not been approved in the US. [1]
How much does tesofensine cost?
There is no licensed US price. Products sold as research chemicals are not lawful for human use and are not verified for identity or purity. [4]
Is tesofensine banned by WADA?
It is not named on the WADA Prohibited List, but two sections could capture it: S6 (stimulants) prohibits substances with similar chemical structure or biological effects to listed stimulants in competition, and S0 prohibits any pharmacological substance with no current approval by a governmental health authority. PeptideAgent marks it unclear; tested athletes should treat it as prohibited until their anti-doping organization says otherwise. [5]
Is tesofensine a peptide?
No. It is a small organic molecule (a phenyltropane derivative) taken by mouth. It appears on peptide vendor sites and in peptide clinic menus because it is marketed to the same weight loss customers, not because of its chemistry. [1]
Tesofensine vs semaglutide: which is better for weight loss?
Semaglutide has far stronger evidence: about 15% average weight loss at 68 weeks in a 1,961 person trial, proven cardiovascular benefit, and FDA approval. Tesofensine's 9 to 11% placebo adjusted loss comes from one 24 week study of 203 people with unresolved cardiovascular questions and no US approval. The comparison is between a proven, available drug and an unproven, unavailable one. [1] [2]
Decisions about starting, stopping, or combining any treatment belong with a licensed clinician who knows your history.
From the blog
- Peptides for weight loss, ranked by human evidence
Tirzepatide, semaglutide, and liraglutide lead on human trials. Retatrutide is trial-only, and AOD-9604 and 5-amino-1MQ are animal-only. Ranking, legal status, and dated prices.
Sources
Numbered citations above point to these primary sources. PubMed entries link to the indexed abstract.
- [1]Astrup A et al. Effect of tesofensine on bodyweight loss, body composition, and quality of life in obese patients: a randomised, double-blind, placebo-controlled trial. Lancet 2008PubMed 18950853, 2008
- [2]Doggrell SA. Tesofensine, a novel potent weight loss medicine. Expert Opin Investig Drugs 2009PubMed 19548858, 2009
- [3]FDA: Bulk drug substances used in compounding under section 503A of the FD&C ActFDA, 2026
- [4]FDA: Certain bulk drug substances for use in compounding may present significant safety risks (Category 2 list, content current as of April 22, 2026)FDA, 2026
- [5]WADA Prohibited List (sections S0 non-approved substances and S6 stimulants)WADA, 2026
- [6]FDA: Compounding inspections, recalls, and other actions (warning letters to compounders)FDA
- [7]FDA warning letters database: July 30, 2019 letter to a 503A pharmacy that compounded BPC-157 acetate outside section 503AFDA, 2019
- [8]FDA Import Alert 66-41: Detention without physical examination of unapproved new drugs promoted in the U.S. (includes peptide entries)FDA
- [9]FDA: Compounding and the FDA, questions and answersFDA
Cite this page
Free to cite and quote with a link. Data is licensed CC BY 4.0 with attribution to PeptideAgent.
- APA style
PeptideAgent. (2026, September 22). Tesofensine: evidence, legality, and access. https://peptideagent.ai/peptides/tesofensine- HTML link
<a href="https://peptideagent.ai/peptides/tesofensine">Tesofensine: evidence, legality, and access</a>, PeptideAgent, updated September 22, 2026.