Tesofensine common uses, half-life, side effects and more

Tesofensine is an oral drug candidate taken for weight loss. It acts like a stimulant and reduces appetite. It was first tested for Parkinson and Alzheimer disease and later moved to obesity research after people in those trials lost weight. Weight-loss trials showed reduced appetite and steady weight loss over several months. No regulator has approved it for any use. It remains a gray-market research chemical. The FDA named it as ineligible for pharmacy compounding in December 2025. That shut the main legal supply route for it. It is also banned in competition under anti-doping rules.

• Gray-market weight loss and appetite control
• Weight management in obesity during calorie restriction
• Adding to a GLP-1 drug to push past a weight-loss plateau
• Hypothalamic obesity (studied with a beta-blocker added)
• Prader-Willi syndrome hyperphagia (studied in the same combination)

Once daily

Obesity trials used 0.25 mg, 0.5 mg, or 1.0 mg by mouth once daily. The 0.5 mg dose became the standard because it kept most of the weight loss with fewer effects on blood pressure, sleep, and mood than 1.0 mg. Community use tracks the trials closely at 0.25 to 0.5 mg by mouth once daily, usually starting at 0.25 mg for a week or two before moving up. A hypothalamic obesity trial paired 0.5 mg tesofensine with 50 mg metoprolol by mouth once daily.

• Take the daily dose in the morning because the long half-life can disrupt sleep
• Start at 0.25 mg and move up only if resting heart rate stays near its baseline
• A beta-blocker such as metoprolol is paired with tesofensine in trials to blunt the rise in heart rate and blood pressure
• The popular on-and-off cycling schedules have no evidence behind them because the appetite effect held through six months of daily use in trials

The terminal half-life is about 234 hours (roughly 9 to 10 days) in humans. The active metabolite lasts even longer at about 374 hours. Blood levels rise for several weeks before they steady. A dose change then takes weeks to show its full effect.

• Dry mouth and insomnia are the most common effects and get stronger at higher doses
• Nausea, constipation, hard stools, and diarrhea are also common
• Resting heart rate rose by 7.4 beats per minute at the 0.5 mg dose
• Blood pressure stayed flat at 0.25 and 0.5 mg but rose at the 1.0 mg dose
• Anxiety, agitation, and restlessness can occur on the drug
• Depressed mood was reported in about 6 percent of people at the higher doses

Tesofensine blocks the presynaptic reuptake of norepinephrine, dopamine, and serotonin. More of each then stays active in the brain. Human PET scans confirm that oral dosing occupies the dopamine transporter in a dose-dependent way. Human studies show more satiety and a lower expected food intake. A short metabolic study also found a small rise in night-time energy use and more fat burning. Rodent studies point to feeding circuits in the lateral hypothalamus. There the drug quiets a subset of appetite-related neurons. That hypothalamic finding comes from one research group and has not been shown in people.

The obesity evidence is moderate but incomplete. The main published trial was TIPO-1. It randomized 203 adults for 24 weeks and found clear placebo-adjusted weight loss at 0.25, 0.5, and 1.0 mg once daily. A later phase 3 program in Mexico reported similar results at the lower doses but was never published in a peer-reviewed journal. The metoprolol combination trial for hypothalamic obesity randomized only 21 adults. Larger trials of that combination are paused for funding rather than safety. The original Parkinson and Alzheimer programs were stopped after the drug did not help those conditions. No regulator has approved it with a label. Early trial reporting was also questioned for undercounting some psychiatric side effects.

• People with heart disease, high blood pressure, or arrhythmia need medical supervision because the drug raises heart rate and can raise blood pressure
• Anyone with anxiety, bipolar disorder, or a history of psychosis should be cautious because the drug can worsen mood and has caused severe anxiety and paranoia in a susceptible patient
• The long half-life means side effects, drug interactions, and dose changes take weeks to settle
• Combining tesofensine with an MAOI, another stimulant, or a serotonergic drug can cause dangerous interactions
• Pregnancy and breastfeeding use should be avoided because safety has not been studied
• Gray-market capsules and powders can carry the wrong dose, identity, or purity