Tirzepatide vs Mounjaro: what's the difference?

The short answer

Tirzepatide is the name of a molecule: a synthetic peptide that activates the GIP and GLP-1 receptors. Mounjaro is a brand name. It is Eli Lilly and Company's prescription medicine whose active ingredient is tirzepatide. Lilly also markets tirzepatide under a second brand, Zepbound, in some countries.

So every Mounjaro pen contains tirzepatide, but tirzepatide on its own is not Mounjaro. The difference is not the molecule's name; it is everything regulators require around a medicine before it can be prescribed.

Friday does not sell Mounjaro, or any other prescription medicine. Friday sells tirzepatide only as lyophilised research material, for laboratory research, education and analytical testing. Friday is not affiliated with Eli Lilly and Company.

Same molecule, different product

Generic names identify a substance. Brand names identify one company's finished, licensed product. Paracetamol and a branded paracetamol tablet are a familiar example of the same split. With tirzepatide the gap between the two is larger, because a peptide medicine involves much more than the active molecule:

• Formulation: a licensed medicine is a finished solution with specified excipients, pH and concentration, delivered in a defined device.
• Manufacturing: it is made under Good Manufacturing Practice (GMP) at inspected sites, with validated processes and release testing on every lot.
• Evidence: its approval rests on the clinical trial programme for that specific product, such as the SURPASS and SURMOUNT trials.
• Labelling and oversight: it carries an approved label, patient information and pharmacovigilance (ongoing safety reporting) required by each national regulator.

Research-use tirzepatide shares the molecule, but none of that regulatory package. It is a raw material for lab work, supplied as a freeze-dried powder and labelled for research use.

Side by side

Why the regulatory status matters

An approved medicine has been evaluated for a specific use in specific people, at a specific strength, from a specific manufacturing process. Research material has not. That is why research peptides are sold with research-use labelling and why reputable suppliers refuse to give medical or personal-use advice.

The status also changes what you should check. For a medicine, the regulator and the pharmacy carry most of the quality burden. For research material, the burden is on the buyer, so the batch's certificate of analysis matters most. Look for an independent lab name, a batch number that matches the vial, identity by mass spectrometry, and purity and content by HPLC. Our guide to buying peptides in Thailand covers what else to look for.

If you are considering any medicine for yourself, that is a conversation for a licensed doctor or pharmacist, not a research supplier.

What about Ozempic, Wegovy and semaglutide?

These names are often searched alongside Mounjaro, but they refer to a different molecule. Semaglutide is a GLP-1 receptor agonist (it does not act on the GIP receptor) developed by Novo Nordisk, which markets it as Ozempic and Wegovy, among other brands. In the SURPASS-2 trial, tirzepatide was compared directly with semaglutide in adults with type 2 diabetes.

Friday does not sell semaglutide, Ozempic or Wegovy. For research compounds in the incretin area that Friday does stock, see tirzepatide, retatrutide and the full shop.

What Friday sells

Friday stocks research-use tirzepatide in 10mg (฿1,890) and 20mg (฿3,460) vials, as lyophilised powder in sealed, labelled vials. It is sold to adults aged 20 and over who accept our research-use terms, with prices in Thai baht. Orders are packed in Bangkok and leave with tracking the next working day, to any address in Thailand. Delivery is a flat ฿60, prices are in Thai baht, and payment is by bank transfer with a slip that our team confirms before dispatch.

For the science behind the molecule and the published trials, read tirzepatide in Thailand.