How to tell if your tirzepatide is real

How do I know if my tirzepatide is real?

You know by testing the vial, not by inspecting it. Tirzepatide is a white powder, and so are most other peptides, fillers and salts. Nothing about colour, cake shape, cap colour or label print tells you which molecule is inside or how much of it there is.

A useful answer comes from three measurements made on a sample from your batch: an identity test that confirms the molecule is tirzepatide, a purity test that shows how much of the material is that one molecule, and an amount test that compares the milligrams in the vial with the number on the label. Each answers a different question, and none of them can stand in for the others.

Why can't I tell by looking at the vial?

Because the problems that matter are invisible. The US Food and Drug Administration warns that counterfeit GLP-1 products "could contain the wrong ingredients, contain too little, too much or no active ingredient at all" (FDA, unapproved GLP-1 drugs). The same page notes products "falsely labeled 'for research purposes' or 'not for human consumption'". A wrong molecule, a short fill and a correct fill all look the same in a sealed vial.

Packaging is also easy to copy. A neat label, a hologram sticker, a batch code and a printed purity figure cost very little to produce. They tell you how much effort went into the packaging, not what went into the vial.

What does "real" mean for a vial of tirzepatide?

Most buyers mean several things at once. It helps to separate them, because each one needs its own test.

• It is the right molecule. Tirzepatide is a 39 amino acid synthetic peptide with an average molecular weight of about 4813.5 g/mol. The main risk is a different GLP-1 class peptide sold under the tirzepatide label.
• It is mostly that molecule. Synthetic peptides carry related impurities, such as chains missing one amino acid. Purity testing measures how much of the material is the main peptide.
• The amount matches the label. A genuine but underfilled vial is still a problem. Only an amount test against a reference standard tells you how many milligrams are present.
• It is not contaminated with endotoxin. Endotoxin comes from bacteria and is measured by a separate test. It says nothing about identity or amount.

Is the seller's certificate of analysis enough?

A certificate is a starting point, not proof. Published research shows how often supplier paperwork and independent results disagree. In one study of 98 synthetic research peptides that all came with certificates claiming at least 95% purity, only 43 met that figure when the researchers ran their own analysis (Verbeke et al., Journal of Pharmaceutical Analysis, 2015).

A 2024 study bought three semaglutide vials from online sellers that claimed 99% purity. Semaglutide made up only 7.7% to 14.37% of the powder weight in those vials, even though each held more semaglutide than its label stated (Ashraf et al., Journal of Medical Internet Research, 2024). That study looked at semaglutide, not tirzepatide, but the lesson carries over: a printed purity figure says nothing about what else is in the powder, and it is a claim until someone tests the vial.

If you do have a certificate, check it properly. Does it name the same batch printed on your vial? Does it name the laboratory and the date? Can you verify it with the issuing laboratory? Our guide to reading a peptide certificate of analysis goes through each line, and the COA checker walks you through the same questions for a document you already have.

What should I check before I send a vial for testing?

1. Photograph the sealed vial and its label, including any batch or lot code.
2. Write down where and when you bought it, and the label amount in milligrams.
3. Keep the seller's certificate, if one came with the order, and note whether its batch matches your vial.
4. Run the seller through the legit checklist so you know which questions the test needs to answer.
5. Keep the vial sealed. An opened vial is harder to interpret, because handling after opening can change what is measured.

Which test do I need for tirzepatide?

If you can only afford one question answered, make it identity. A vial of the wrong peptide can still show a clean, high HPLC purity, because purity only says the material is mostly one molecule. Mass spectrometry says which molecule. Tirzepatide's mass is distinct from the other common GLP-1 class peptides, so a correct identity result rules out a straight swap. The identity lesson explains how the mass is read.

If you want to know whether you are getting what you paid for, add the amount test. A vial labelled 30 mg that contains far less is a real loss even when the molecule is right. Purity then tells you about the quality of what is there. You can see the full panel and what each part reports on the tirzepatide test page.

How does testing through Tested.ph work?

Tested.ph is not a laboratory. It takes your order, gives the sealed vial a sample code so the analyst never sees the seller's name, and sends it to a partner laboratory. The partner laboratory runs identity by mass spectrometry, purity by HPLC and amount against a reference standard, with endotoxin as an optional extra. The partner laboratory will be named on the site before testing opens.

Each report is signed by the partner laboratory's registered chemist. In the Philippines, the Chemistry Profession Act covers both performing and certifying a chemical analysis, and a document from the practice of chemistry is not considered official unless it is signed by a registered chemist with their registration number (RA 10657, Sections 4 and 40).

Each published record gets a task number and a key, for example 1042-K7QX9M. Anyone holding both can check the record at tested.ph/verify, so a screenshot cannot be passed off as a result. The full process is on how it works, and costs are on pricing. If several people bought from the same batch, a group test lets them share one result.

What can a test not tell me?

A result describes the sample that was analysed. It is strong evidence about that vial and reasonable evidence about the batch it came from, but it does not guarantee every vial a seller ships. Batches change, and a seller with one good result can still ship a poor batch later. That is why the Tested Index scores sellers only on vials bought anonymously, across several batches.

A test also says nothing about whether a product is registered, legal to sell, or appropriate for anyone to use. It is a chemical description of a sample. For a plain list of these limits, read what a peptide test can and cannot tell you.