What is the difference between Reta and Mounjaro?
Mounjaro is the brand name of tirzepatide. It is an injectable medicine that activates two gut hormone receptors, GIP and GLP-1, and it is registered in Malaysia: the NPRA product register, searched for the article on buying Ozempic or Mounjaro online in Malaysia on 30 September 2026, listed it. It is a prescription medicine, and whether it suits a person is a doctor's decision.
"Reta" is the name used online for retatrutide. It is an experimental medicine that activates the same two receptors and a third, the glucagon receptor. That is why it is called a triple agonist. It is made by the same company that makes tirzepatide, is still in clinical trials, and has no registration in Malaysia. The two names sound alike, but one is a medicine with a registration and a leaflet, and the other is a trial drug.
What do the trials report for tirzepatide?
In SURMOUNT-1, 2539 adults with obesity, or overweight with a complication, and without diabetes were given tirzepatide or placebo once weekly for 72 weeks. Mean weight change at week 72 was -15.0%, -19.5% and -20.9% across the three trial doses, against -3.1% with placebo. The most common adverse events were gastrointestinal, mostly mild to moderate and mainly during dose escalation. Adverse events led 4.3% to 7.1% of people on tirzepatide to stop, against 2.6% on placebo.
A fuller account of how it works and who it suits is in the tirzepatide explainer, and how it sits next to semaglutide and liraglutide is in the comparison of GLP-1 medicines.
What do the trials report for retatrutide?
The phase 2 trial, published in the New England Journal of Medicine in 2023, enrolled 338 adults for 48 weeks. Mean weight change at 48 weeks was -24.2% in the 12 mg group, against -2.1% with placebo. Gastrointestinal events were the most common and rose with dose, and heart rate also rose with dose, peaking at 24 weeks.
Phase 3 results followed in 2026. TRIUMPH-1, published in the same journal on 29 September 2026, gave retatrutide or placebo to 2339 adults with obesity and without diabetes for 80 weeks. Mean weight change was -17.6%, -23.7% and -25.0% across the three trial doses, against -3.9% with placebo. TRIUMPH-2, in 1152 adults with obesity and type 2 diabetes, was published in The Lancet on 10 October 2026: -11.9%, -16.8% and -18.8% against -5.1%. In that trial, hypotension and dysesthesia, an abnormal skin sensation, were more frequent with retatrutide than with placebo (dysesthesia 7% in the highest-dose group against 1%), and permanent discontinuation because of adverse events or death was 12% in the 9 mg group and 8% in the 12 mg group, against 5% with placebo.
Both phase 3 trials were funded by the manufacturer. They are evidence about the trial product in trial conditions. They are not a registration.
Can the two be compared directly?
Not safely. The tirzepatide and retatrutide figures above come from different trials, with different lengths (72, 48 and 80 weeks), different doses and different groups of people. No trial read for this article compared the two medicines head to head, so the percentages cannot be lined up as a league table. What the papers do show is that both medicines are studied, that both cause gastrointestinal effects that rise with dose, and that the retatrutide evidence is newer.
A comparison of "Reta" with Mounjaro that quotes percentages is lining up numbers from separate papers. No paper says a pen from a chat group will behave like either.
Why is only one of them registered in Malaysia?
Registration is the regulator's decision, made on a manufacturer's submitted evidence about quality, safety and effect. As reported by Free Malaysia Today on 28 August 2026, the Ministry of Health (KKM) said that, as of 17 August 2026, no product containing retatrutide had been registered with the drug regulatory authority. It described the drug as experimental, in phase three trials, and said no regulator in the world had approved it. Those statements are dated. A later registration, if one comes, would be announced by the Ministry and would appear on the NPRA register.
The same report records that KKM urged the public not to buy or use weight-loss pens claimed to contain retatrutide. It reported 30 raids in the period it covered and 209 adverts removed from e-commerce platforms, and said that selling unregistered medicines is an offence under the Sale of Drugs Act 1952. How aesthetic and medical products are regulated in Malaysia sets out the wider picture.
Why does a pen sold as "Reta" have unknown contents?
Because nothing stands between the maker and the buyer. A registered medicine has been assessed for what is in it, how strong it is and how it is made, and it carries a registration number and a hologram. An unregistered pen has none of those checks. The label can say retatrutide and the pen can hold something else, a different strength, a different substance or nothing useful. Nobody outside the seller can tell, and the buyer cannot tell by looking.
Sterility is the other question. An injection goes under the skin, so how it was made, filled and stored matters. A pen that was not made under a regulated process has no one accountable for that. The trial product in the papers was made under trial conditions. A pen advertised as the same thing has no such link to it.
The trial effects reported above also include the ones that need a doctor's eye, such as the heart rate rise in the phase 2 trial. A person using an unknown product in an unknown dose has no doctor watching for them.
How do I check whether a product is registered?
Find out what the product is, then search it. A medicine has a MAL number, searched on the NPRA product search, and KKM advises checking the FarmaTag hologram on the MyUbat app. The steps are in how to check if a product is KKM approved. A search that finds nothing is an answer, and it is the one the Ministry gave on retatrutide.
The register shows only that a product exists and is listed. It cannot show that the box in your hand is genuine, which is where the hologram check and a pharmacist help.
Where does a doctor come in?
A registered medicine for weight is still a prescription medicine. Whether tirzepatide or any other medicine suits a person depends on their health, other medicines and goals, and that is for a doctor to decide after an assessment. The clinic's page on medical weight management describes the clinic's service. This article is general information, not advice about any medicine.
