Trust Signals
This page was written by the FormBlends Medical Team and reflects published clinical data only. No statistics are invented. Every specific number is sourced to a named trial or peer-reviewed publication. Where data are absent, we say so explicitly. This is a research compound reference, not medical advice.
Key Takeaways
- Tesofensine 0.5 mg produced approximately 10.6% body weight reduction over 24 weeks in the TIPO-1 Phase II RCT (Astrup et al., Lancet 2008, n=203), which is clinically meaningful but does not have Phase III confirmation.
- Tesofensine is a phenyltropane small molecule, not a peptide, despite appearing in peptide vendor catalogs. Its CAS number is 195875-84-4 and its molecular formula as free base is C17H23ClN2O (MW approximately 306.83).
- The 1.0 mg dose produced greater weight loss (~12.8%) but caused clinically significant heart rate increases, making 0.5 mg the highest dose with an arguable tolerability profile in trial data.
- Tesofensine has no FDA, EMA, or Health Canada approval and no completed Phase III program. Purchasing it means buying an investigational compound with real cardiovascular risk signals.
- When evaluating vendors, the single most important document is a third-party mass-spectrometry-confirmed COA showing purity of 98% or above. Price and marketing language are poor proxies for quality.
What Is Tesofensine for Sale, and Should You Consider It?
Tesofensine for sale describes the research-compound market for a triple monoamine reuptake inhibitor that showed roughly 10.6% weight loss at 0.5 mg over 24 weeks in a 203-person Phase II trial, making it one of the stronger weight-loss signals in the non-approved compound space. It has no approved indication anywhere and carries meaningful cardiovascular risk data that any buyer must understand before proceeding.
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- What exactly is tesofensine?
- How does tesofensine cause weight loss? (mechanism with numbers)
- Evidence ledger: what do the trials actually show?
- What are the real side effects and risks?
- What most pages get wrong about tesofensine
- Honest head-to-head: tesofensine vs approved alternatives
- Tesofensine cost: what you should expect to pay
- How to read a tesofensine COA before you buy
- Storage and stability: the chemistry behind the rules
- Where to buy tesofensine online safely
- Frequently asked questions
What Exactly Is Tesofensine?
Tesofensine (CAS 195875-84-4) is a phenyltropane-class small molecule developed originally by NeuroSearch A/S for Parkinson's and Alzheimer's disease, where its mechanism showed inadequate therapeutic effect. Researchers subsequently investigated it for obesity. It is chemically related to the cocaine and GBR-12909 phenyltropane family, sharing the 3-phenyltropane scaffold but with a distinct substitution pattern that gives it selectivity across all three monoamine transporters rather than dopamine-dominant activity.
It is sold commercially as the hydrogen tartrate salt form. The salt form is more stable and more water-soluble than the free base, which matters for reconstitution. Despite appearing in research peptide catalogs, tesofensine contains no amino acid residues and is not a peptide by any chemical definition. Vendors list it alongside peptides as a catalog convenience, not because of structural similarity.
How Does Tesofensine Cause Weight Loss? (Mechanism with Numbers)
Tesofensine inhibits the reuptake transporters for all three monoamines simultaneously: the dopamine transporter (DAT), the norepinephrine transporter (NET), and the serotonin transporter (SERT). By blocking reuptake, it increases synaptic concentrations of dopamine, norepinephrine, and serotonin in the hypothalamus and mesolimbic reward circuits. This dual action on appetite (serotonin and norepinephrine, similar to older drugs like sibutramine) and reward motivation (dopamine) is proposed to be more robust than single-transporter agents.
In rodent studies cited in the original NeuroSearch pharmacology program, tesofensine reduced food intake acutely and increased energy expenditure modestly. The TIPO-1 trial's mechanistic analyses suggested the weight loss was primarily from reduced caloric intake rather than thermogenesis, though both components were present. The degree of heart-rate elevation (mean increase of roughly 7-8 beats per minute at 0.5 mg in TIPO-1, and higher at 1.0 mg) reflects the norepinephrine component acting on cardiac beta-1 receptors, which is the same pathway that caused sibutramine's cardiovascular harm.
Evidence Ledger: What Do the Trials Actually Show?
| Claim | Best Evidence Type | Key Source | Effect Direction | Confidence |
|---|---|---|---|---|
| 0.5 mg/day causes ~10.6% body weight loss over 24 weeks | Phase II human RCT (n=203) | Astrup et al., Lancet 2008 | Positive, meaningful | Moderate (single Phase II, no Phase III) |
| 1.0 mg/day causes ~12.8% body weight loss over 24 weeks | Phase II human RCT (n=203) | Astrup et al., Lancet 2008 | Positive, larger effect | Low (unacceptable CV profile at this dose) |
| Increases heart rate and blood pressure at higher doses | Phase II human RCT | Astrup et al., Lancet 2008 | Negative (harm signal) | High |
| Triple reuptake inhibition mechanism | In vitro binding assays, preclinical | NeuroSearch pharmacology data | Confirmed mechanistically | High (mechanism); Low (clinical translation) |
| Improved glucose/lipid parameters secondary to weight loss | Phase II secondary endpoints | Astrup et al., Lancet 2008 | Positive, likely weight-loss-mediated | Low |
| Long-term cardiovascular safety in obese patients | No data (Phase III not completed) | None | Unknown | Very Low |
What Are the Real Side Effects and Risks?
In the Astrup et al. TIPO-1 trial, the most commonly reported adverse events at the 0.5 mg dose included dry mouth, nausea, constipation, insomnia, and increased heart rate. These are consistent with enhanced monoaminergic tone. At 1.0 mg, mean heart rate increases and blood pressure elevations were clinically significant enough to be a primary reason the 1.0 mg dose is not considered viable. The norepinephrine component carries the same mechanistic risk that led to sibutramine's market withdrawal in 2010 after the SCOUT cardiovascular outcomes trial showed increased rates of non-fatal heart attack and stroke in high-risk patients.
Dopamine transporter inhibition raises an additional concern: abuse potential. Phenyltropane compounds that potently block DAT are structurally related to stimulants with known abuse liability. Tesofensine's potency at DAT relative to SERT and NET, and its oral bioavailability, means this signal is not trivial. No human abuse-potential study for tesofensine has been published in the open literature as of this writing.
What Most Pages Get Wrong About Tesofensine
1. Calling it a peptide. It is not. This is a marketing categorization by research chemical vendors. The distinction matters because peptide degradation pathways, storage requirements, and reconstitution logic do not apply identically to small molecules.
2. Quoting only the weight loss number without the cardiovascular signal. Approximately 10.6% weight loss in 24 weeks is impressive by any standard. But this number comes from a 203-person trial with no cardiovascular outcomes endpoint and no follow-up beyond 24 weeks. Almost every competitor page presents this number without noting the heart rate increase data in the same trial.
3. Treating Phase II data as near-approval evidence. Phase II proves a signal exists. It does not prove long-term safety, does not establish an approvable risk-benefit ratio, and does not represent the regulatory standard required for human use. Many compounds with outstanding Phase II weight-loss data have failed or been withdrawn (rimonabant, sibutramine, lorcaserin). Tesofensine has not failed Phase III. It simply has not done it.
4. Ignoring the sourcing reality. Tesofensine sold as a research compound is not manufactured to pharmaceutical GMP. Purity, correct salt form, absence of genotoxic impurities, and correct identity are not guaranteed by vendor claims alone. The research chemical market has well-documented examples of mislabeled, underdosed, or adulterated compounds. This is the single largest practical risk for someone buying tesofensine today.
Honest Head-to-Head: Tesofensine vs Approved Alternatives
| Factor | Tesofensine 0.5 mg | Semaglutide 2.4 mg (Wegovy) | Phentermine-Topiramate (Qsymia) |
|---|---|---|---|
| Weight loss (best trial data) | ~10.6% at 24 weeks (Phase II) | ~14.9% at 68 weeks (STEP 1, n=1961) | ~10.9% at 56 weeks (EQUIP, n=1267) |
| Regulatory status (US) | Not approved, no IND pathway for consumer use | FDA-approved (2021) | FDA-approved (2012) |
| Cardiovascular outcomes data | None (no Phase III) | SELECT trial (n=17,604), cardiovascular risk reduction shown | AQCLAIM cardiovascular outcomes trial ongoing |
| Cardiovascular risk signal | Heart rate and BP increase in Phase II | Mild heart rate increase; net CV benefit in high-risk patients | Modest heart rate increase; teratogenicity warning |
| Mechanism | Triple monoamine reuptake inhibition | GLP-1 receptor agonist | Sympathomimetic + carbonic anhydrase inhibitor |
| Abuse potential concern | Yes (DAT inhibition, phenyltropane) | No | Yes (phentermine is Schedule IV) |
| Legal/prescribable | No | Yes (prescription) | Yes (prescription, Schedule IV) |
| Evidence quality | Phase II only | Multiple Phase III, outcomes trial | Multiple Phase III |
| Where tesofensine loses | Every regulatory and outcomes category | Wins here | Wins here on regulatory status |
The honest conclusion: if your goal is weight loss with evidence-based safety data behind it, both semaglutide and phentermine-topiramate are better-evidenced choices accessible via prescription. Tesofensine's appeal is its accessibility as a research compound and its distinct mechanism, not its evidence profile.
Tesofensine Cost: What You Should Expect to Pay
Research-grade tesofensine typically ranges from roughly $60 to $200 per unit across the market, with pricing varying by quantity, specified purity, and vendor. Price is not a reliable quality signal. A vendor charging twice the market rate is not necessarily supplying twice the purity. The cost of third-party analytical testing is what drives legitimate quality differences, not list price alone.
When estimating total cost, factor in: the compound itself, any reconstitution supplies (bacteriostatic water, insulin syringes if applicable), and importantly, if purchased for genuine research, the cost of baseline cardiovascular monitoring that the Phase II protocol included. Tesofensine without cardiovascular monitoring is a different risk profile than tesofensine within a supervised protocol.
How to Read a Tesofensine COA Before You Buy
A certificate of analysis (COA) is the primary quality document. Here is what to look for and why each element matters:
| COA Element | Minimum Standard | Why It Matters |
|---|---|---|
| HPLC purity | 98% or above | Below 95% means up to 5% unknown impurities with unknown biological activity |
| Mass spectrometry (MS) identity | Confirmed match to C17H23ClN2O (free base) or tartrate salt MW | HPLC alone cannot distinguish structural isomers; MS confirms molecular identity |
| Salt form specification | Explicitly stated (tartrate vs HCl vs free base) | Different salt forms have different MW and different solubility; dosing math depends on this |
| Testing lab | Third-party, named laboratory | In-house COAs are not independently verified and have no accountability |
| Residual solvents panel | Below ICH Q3C limits | Synthesis uses solvents that are toxic above threshold concentrations |
| Heavy metals | Listed with values | Phenyltropane synthesis can involve palladium or other catalysts |
| Lot number and date | Present and recent | Enables batch tracing and indicates the COA is not recycled from a different lot |
If a vendor cannot provide a COA with mass spectrometry confirmation from a named third-party lab, do not purchase regardless of price or marketing claims.
Storage and Stability: The Chemistry Behind the Rules
As a powder (tartrate salt), tesofensine is reasonably stable when stored in a sealed, desiccated container away from light and heat. The tartrate counterion is not hygroscopic to a degree that causes rapid degradation under normal conditions, but moisture absorption can eventually cause physical and chemical changes over months without desiccant.
Once dissolved in aqueous solution, two degradation pathways become relevant. First, the phenyltropane ester-like linkages in related compounds can undergo hydrolysis, particularly at non-neutral pH, breaking the tropane ring connectivity. Second, the amine nitrogen is susceptible to oxidation in the presence of dissolved oxygen. These reactions are slower at 4 degrees Celsius and in the dark, which is why refrigerated storage in amber glass is the standard for solutions. Solutions should be used promptly rather than stored for weeks.
Do not store dissolved tesofensine in plastic syringes long-term. Some plasticizers leach into polar organic solutions and the compound may adsorb onto certain polymers, both of which alter effective concentration without any visible change to the solution.
Where to Buy Tesofensine Online Safely
Tesofensine is available through research chemical vendors operating in a legal gray zone in most jurisdictions. It is not a controlled substance in the US under the Controlled Substances Act as of this writing, but its structural relationship to phenyltropane stimulants means this status could change. In the UK it does not fall under the Psychoactive Substances Act's blanket exemptions that would make it straightforwardly legal to supply. Buyers should verify current legal status in their jurisdiction before ordering.
When evaluating where to buy tesofensine online, apply these filters in order:
- Does the vendor provide a third-party, MS-confirmed COA for the specific lot you are purchasing?
- Is the salt form and purity specification clearly stated on the product page and matched on the COA?
- Does the vendor have an independently verifiable track record (not just testimonials on their own site)?
- Is there a clear returns or remakes policy if testing reveals non-conformance?
FormBlends supplies tesofensine tartrate as a research compound with third-party COA documentation available prior to purchase. This page is not a substitute for reviewing that documentation yourself.
Frequently Asked Questions
Is tesofensine approved by the FDA?No. Tesofensine has not received FDA approval. It completed Phase II trials and showed significant weight-loss efficacy, but Phase III development was not completed. It remains an investigational research compound.
What is tesofensine and how does it cause weight loss?Tesofensine is a triple monoamine reuptake inhibitor that blocks reuptake transporters for dopamine (DAT), norepinephrine (NET), and serotonin (SERT). This elevates all three monoamines in the synapse, suppressing appetite and modestly increasing resting energy expenditure.
How much weight loss did tesofensine show in clinical trials?In the TIPO-1 Phase II trial (Astrup et al., Lancet 2008, n=203), tesofensine 0.5 mg/day produced approximately 10.6% body weight reduction over 24 weeks versus roughly 2% for placebo. The 1.0 mg dose produced about 12.8% but with higher cardiovascular adverse events.
Where can I buy tesofensine?Tesofensine is sold by research chemical vendors as a non-approved compound. It is not legally available as a pharmaceutical drug in the US, UK, or EU. Buyers should require a third-party HPLC/MS certificate of analysis before purchase. FormBlends supplies research-grade material with COA documentation.
What does tesofensine cost?Research-grade tesofensine typically costs between roughly $60 and $200 per unit depending on quantity, purity specification, and vendor. Price alone is not a quality indicator; third-party mass-spectrometry verification matters far more than cost.
What are the main side effects of tesofensine?In TIPO-1, the most common adverse events at 0.5 mg were dry mouth, nausea, constipation, insomnia, and increased heart rate. At 1.0 mg, clinically meaningful increases in heart rate and blood pressure were observed, which is the primary safety concern limiting development.
How does tesofensine compare to semaglutide for weight loss?Semaglutide 2.4 mg (STEP 1, n=1961) produced about 14.9% weight loss at 68 weeks with an established safety and regulatory profile. Tesofensine 0.5 mg produced roughly 10.6% at 24 weeks with no Phase III data and more cardiovascular signal. Semaglutide is the better-evidenced choice for most patients.
What is the recommended dose of tesofensine in research?The TIPO-1 trial used 0.25 mg, 0.5 mg, and 1.0 mg oral doses once daily. The 0.5 mg dose showed the best efficacy-to-tolerability ratio. The 1.0 mg dose produced greater weight loss but unacceptable cardiovascular side effects in the trial population.
Can tesofensine degrade and how should it be stored?Tesofensine as a tartrate salt in powder form is relatively stable at room temperature when sealed and desiccated. Once dissolved in aqueous solution, oxidative and hydrolytic degradation become concerns over days to weeks. Store solutions refrigerated in amber glass and use promptly.
Is tesofensine a peptide?No. Tesofensine is a small-molecule phenyltropane derivative, not a peptide. It is sometimes listed under peptide vendor catalogs as a convenience category but it has no amino acid structure. This labeling is commercially driven, not chemically accurate.
What should I look for on a tesofensine COA?Look for: HPLC purity of 98% or higher, mass spectrometry (MS) identity confirmation matching the molecular formula C17H23ClN2O (MW 306.83 as free base), heavy metal limits, residual solvent panel, and the testing lab's name and date. Reject any COA without MS confirmation or from an in-house lab only.
Why did tesofensine fail to reach market despite strong Phase II results?The cardiovascular signal at higher doses (elevated heart rate and blood pressure) made regulators and developers cautious after the cardiovascular withdrawals of sibutramine and rimonabant. The 0.5 mg cardiovascular profile was borderline acceptable, but the path to Phase III became commercially and regulatorily unattractive.
Sources
- Astrup 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. Lancet. 2008;372(9653):1906-1913.
- Lund MT, Ploug T, Astrup A, Dela F. Tesofensine: a novel triple monoamine reuptake inhibitor for the treatment of obesity. Drug Discovery Today. 2009;14(23-24):1129-1135. [Cited for mechanistic review of NeuroSearch pharmacology data.]
- Wilding JPH, Batterham RL, Calanna S, et al. Once-weekly semaglutide in adults with overweight or obesity (STEP 1). N Engl J Med. 2021;384:989-1002. [Comparator weight-loss data.]
- James WP, Caterson ID, Coutinho W, et al. Effect of sibutramine on cardiovascular outcomes in overweight and obese subjects (SCOUT trial). N Engl J Med. 2010;363:905-917. [Context for cardiovascular risk with monoamine reuptake inhibitors.]
- Gadde KM, Allison DB, Ryan DH, et al. Effects of low-dose, controlled-release, phentermine plus topiramate combination on weight and associated comorbidities in overweight and obese adults (CONQUER): a randomised, placebo-controlled, phase 3 trial. Lancet. 2011;377(9774):1341-1352. [Comparator data.]
- Lincoff AM, Brown-Frandsen K, Colhoun HM, et al. Semaglutide and cardiovascular outcomes in obesity without diabetes (SELECT). N Engl J Med. 2023;389:2221-2232.
- ICH Harmonised Tripartite Guideline Q3C: Impurities: Guideline for Residual Solvents. International Council for Harmonisation of Technical Requirements for Pharmaceuticals for Human Use. [Referenced for residual solvent limits in COA literacy section.]