Tirzepatide API: What a US Buyer Must Verify First

Tirzepatide API is the active pharmaceutical ingredient (API): the bulk, synthetic peptide that makes a tirzepatide drug work, supplied as powder. It is not a sterile, dosed injection. Tirzepatide is a dual agonist of the GLP-1 and glucose-dependent insulinotropic polypeptide (GIP) receptors. The Zepbound prescribing information gives its molecular weight as 4813.53 daltons and its formula as C225H348N48O68.

The finished single-dose product is a 0.5 mL solution containing 2.5 to 15 mg of tirzepatide plus sodium chloride, sodium phosphate dibasic heptahydrate and water for injection. Turning powder into that product requires formulation, sterile manufacture and release testing. Purity alone supplies none of it.

No. A drug master file (DMF) is a confidential submission of manufacturing and quality information. FDA states that DMFs are neither approved nor disapproved. It reviews their contents only in connection with an application that references them.

We filtered the Subject column of FDA's quarterly DMF list for "tirzepatide". The list is the second-quarter 2026 edition, covering DMFs received by June 30, 2026. Counted in October 2026:

• 40 DMFs name tirzepatide. All are Type II (drug substance and intermediates) and Active.
• 35 are for the drug substance and 5 are for side-chain or fragment intermediates.
• The 35 drug-substance filings come from 34 holders, because one company filed twice.
• By submission year, the 35 drug-substance filings are 1 in 2023, 14 in 2024, 14 in 2025 and 6 in the first half of 2026.
• Four holders are Indian: Biocon, Alembic, MSN Life Sciences and Dr. Reddy's. By company name, 28 of the 34 are Chinese. The list has no country column, so that split is our reading of the names.
• For comparison, the subject lines of 95 DMFs name semaglutide and 28 name liraglutide.

Filing is common, and our inference is that a DMF number alone separates few suppliers. What matters is whether the DMF holder is the company making your lot, and whether the holder has given you a letter of authorization (LOA). That letter lets FDA consult the file for your application.

FDA Import Alert 66-80 lets staff detain foreign GLP-1 API without physical examination (DWPE, detention without physical examination), unless the producing site and product appear on its Green List. A DMF and a site registration do not exempt a shipment. A Green List entry does.

In the version published September 21, 2026, Import Alert 66-80 reports that FDA evaluated 48 GLP-1 API sites, across all GLP-1 products and not tirzepatide alone. It found 21% noncompliant with current good manufacturing practice (CGMP) or unresponsive to records requests, which is about 10 sites by our arithmetic. Some sites registered, offered material for import, ignored records requests and deregistered within a short period. Registration, then, is not the test.

We counted the Green List on that page. It has 21 firm entries: 12 under China, 3 under India, and 1 each under Belgium, Canada, Denmark, Ireland, Portugal and Italy. Nine lines name tirzepatide, eight under China and one under Canada. India's three entries cover liraglutide (two) and exenatide (one). No tirzepatide line sits under India, although four Indian companies hold tirzepatide DMFs.

To be added, a firm must submit evidence including certificates of analysis for its last ten GLP-1 API lots (or all, if fewer), release specifications with their justification, stability data, process validation, master and recent batch records, an equipment list, out-of-specification results and a five-year summary of complaints and recalls.

The list changes, so read the current alert before every purchase. Our recommendation: ask the supplier to point to its own tirzepatide entry. If it cannot, plan for detention risk before you pay.

No. A certificate of analysis (COA) is the supplier's test report for one lot, and it is only as reliable as the lot it describes, the laboratory behind it and the tests it includes. A COA for a different lot proves nothing about the powder you receive.

Check four things:

• Lot match: the COA lot number equals the label and shipment lot, and a named laboratory issued it.
• Identity and content: mass spectrometry confirms the molecular weight, and the COA reports net peptide content (the share of the powder that is peptide). High-performance liquid chromatography (HPLC) purity, a peak-area percentage, is not the same measure; see peptide HPLC purity versus content.
• Salt form: FDA has stated, in the context of compounding, that semaglutide sodium and semaglutide acetate are different active ingredients from those in the approved drugs. Our inference is that the same question applies to tirzepatide, so the counterion should be on the COA and match your reference drug.
• History: ask for several lots, not one. FDA's own Green List request asks for ten.

FDA also expects bulk substances to come with valid COAs from registered facilities, as its guidance for compounders states. For a drug program, our recommendation is to run your own release testing on the received lot.

A gram of tirzepatide API covers about 67 weekly doses at the labeled maximum of 15 mg, if the powder were 100% peptide. Real lots contain less, so the net peptide content on the COA sets the true number.

This is our model, not an official figure: doses = quantity in mg × net peptide content ÷ 15 mg, with the 15 mg maximum from the Zepbound label.

Replace 100% with the assay value on your COA. Our prices depend on chemical rates and market conditions, so we quote per request once you give the API name and CAS number (Chemical Abstracts Service registry number).

A tirzepatide API supplier screen should have 12 checks, each with a pass or fail you can run from documents. Any fail in checks 1 to 4 should stop the purchase. This is our recommendation, built from FDA's DMF and import-alert requirements; for the wider qualification process, see peptide API supply chain qualification.

Check 12 matters because FDA has warned about sellers of tirzepatide that is falsely labeled "for research purposes" or "not for human consumption".

We are a pharmaceutical API sourcing, supply and export partner for qualified business-to-business (B2B) buyers, and tirzepatide sits in our peptide portfolio as bulk API or raw powder, not finished vials. Apply the 12-check screen to us as you would to anyone.

As of October 2026, Aarise Pharmaceuticals does not appear among the tirzepatide DMF holders counted above, and we do not claim a Green List entry. We supply tirzepatide as bulk powder for evaluation and B2B review. Our peptide product page currently lists both tirzepatide grades (98% and 99% purity) as sold out, so availability is confirmed at quotation.

Send the product name or CAS number, quantity, destination, grade or purity, required documents, payment terms and Incoterms (international shipping terms). We review availability and documentation against your destination market, and share the certificate of analysis, specifications and safety data sheet where applicable. Sample quantity, price, minimum order and lead time are confirmed per product in the quotation.

International commercial orders are generally 100% advance by bank transfer unless agreed in writing. We do not present research-only material as human pharmaceutical API. Buyers remain responsible for confirming local registration, import authorization and permitted end use.

Contact our team (choose Product Information), by WhatsApp on +91 9899783330, or at sunil@aarisepharma.com.