Where are peptides made? How research peptides are produced, and why so many come from China

Where are peptides made: the answer in brief

Peptides sold in vials are made in factories. A peptide is a short chain of amino acids, typically 2 to 50, linked by peptide bonds (NHGRI). Cells in the body make peptides too, but research peptides are built by chemistry or grown in engineered cells.

Many of the research peptides sold online start at manufacturers in China. Public test databases point that way, and FDA records show a large role for China in peptide drug ingredients. We found no published, sourced figure for the share, so this guide gives none.

Where a peptide was made does not tell you what is in one vial. Only a test of the vial does.

How peptides are made

There are three chemical routes and one biological route in large-scale use.

Route	How it works	Example from a regulator or study
Solid-phase synthesis (SPPS)	The chain is built on resin beads, one protected amino acid at a time, then cut off, purified and freeze-dried	A generic liraglutide authorised in the EU is made by SPPS (EMA assessment report)
Liquid-phase synthesis (LPPS)	The chain is built in solution	Named with SPPS and hybrids as the main routes in a study of process data from 14 drug companies (J Org Chem, 2024)
Hybrid SPPS/LPPS	Short fragments made by SPPS are joined in solution	Tirzepatide is a recent production-scale example, per the same study
Recombinant expression	Engineered cells make the chain, which is then purified	The semaglutide in the licensed medicine is produced in yeast cells by recombinant DNA technology (EMA product information)

Bruce Merrifield received the 1984 Nobel Prize in Chemistry for developing chemical synthesis on a solid matrix, the basis of SPPS. The 2024 study describes SPPS as the predominant platform for peptide synthesis.

The route does not change the molecule. In its report on the generic liraglutide, the EMA states that the structure is the same for synthetic and biologic liraglutide. The original products use recombinant liraglutide; the generic uses SPPS.

The route does leave traces. SPPS relies on trifluoroacetic acid (TFA) to cut the chain from the resin and as an ion-pairing reagent in purification, so synthetic peptides are often obtained as TFA salts (Pharmaceuticals, 2025). Solvents from synthesis can also remain. A counter-ion test and a residual solvents test measure these traces. They describe the process; they cannot name the country. Our guides on TFA in peptides and residual solvents explain each test.

Are most peptides made in China?

No public dataset counts research peptides by country. Each record below shows one part of the picture, and each has a limit.

Record	What it shows	Its limit
FDA Import Alert 66-80, published 21 September 2026	GLP-1 ingredients used for compounding in the US during the shortages came from makers around the world, including China, India and Europe. 12 of the 21 firms on its green list are in China	GLP-1 ingredients imported into the US only
FDA testimony to Congress, October 2019	In August 2019, 13% of facilities making drug ingredients for the US market were in China, 18% in India, 26% in the EU and 28% in the US	All drug ingredients; it counts facilities, and volumes may differ
Finnrick public leaderboards, early October 2026	On 8 of 30 product leaderboards, the seller ranked first has a place in China in its name, such as Shanghai, Shandong or Yiwu	Only sellers whose products were tested; a name is not an address
Public results page of Janoshik, a lab in the Czech Republic, September 2026	Many reports on the front page were made public by peptide factories in China, which use them to show buyers their batches	Only reports that clients chose to publish
Our lab survey, September 2026	Among the labs we found testing peptides for this market, none was an independent lab in mainland China marketing to Western buyers. Factories rely on in-house QC; Western sellers send samples to labs in the US and Europe	Covers labs only

Are all peptides made in China? No. The FDA’s green list also names GLP-1 ingredient makers in Belgium, Canada, Denmark, India, Ireland, Italy and Portugal. Are most research peptides made there? The records point to a large share, but none of them measures it.

What peptides come from China

The records name specific products. Firms in China on the FDA green list are listed for semaglutide, tirzepatide and liraglutide, and one firm’s entry names retatrutide. Sellers with a place in China in their names rank first on Finnrick’s boards for GHK-Cu, tesamorelin, TB-500, cagrilintide and four other products. We found no source that maps peptide plants by city or province. For what tests of these products show, see what lab results show about peptides from China.

Why are peptides made in China?

We found no study on why research peptides in particular come from China. The closest primary source covers drug ingredients in general. In October 2019, the director of the FDA’s drug centre told the US Congress that the factors often cited include:

• Labour. Citing a 2009 World Bank paper, a Western ingredient maker’s wage index of 100 compares with 8 for a Chinese company and 10 for an Indian one.
• Utilities. China has lower electricity, coal and water costs.
• Suppliers. Chinese firms sit in a network of raw material and intermediate suppliers, which lowers shipping and transaction costs.
• Environmental rules. They face fewer environmental regulations on buying, handling and disposing of toxic chemicals.
• Growth. The number of registered ingredient facilities in China more than doubled between 2010 and 2019.

These inputs weigh heavily in peptide synthesis. In the 2024 study, SPPS used on average about 13,000 kg of materials per kg of peptide, against medians of 168 to 308 kg for small-molecule drugs, and solvents are the largest part of that mass. In the EMA report, SPPS starts from chemical building blocks: protected amino acids and dipeptides. In 2020, chemists at a European peptide drug maker noted that the classic SPPS solvents DMF, NMP and dichloromethane were heading for restriction or authorisation under EU chemicals law. Linking these facts to research peptides is our reading; no source we found measures it.

A second fact explains why buyers meet these manufacturers directly. Many factories in China sell straight to buyers abroad and post outside lab reports to show their batches, as the Finnrick and Janoshik records above show. Many buyers then deal with the factory, with no reseller in between.

Peptides made in the USA, and “not made in China” claims

The US Federal Trade Commission sets the standard for origin claims. An unqualified “Made in USA” claim means the final processing, all significant processing and all or virtually all ingredients are from the US. The product should have no, or negligible, foreign content. In a vial of peptide, the peptide is the main ingredient.

A US address on a seller’s site or a vial shows where the seller is based or ships from. Filling, labelling and packing can happen in a different place from synthesis. No lab test can settle the question either. If origin matters to you, ask the seller to name the manufacturer and to supply the batch COA, then check that COA.

Buying through a B2B marketplace

Searches such as “made in china website peptides” most likely refer to Made-in-China.com, a general B2B marketplace where suppliers list their own products. Its “Audited Supplier” mark means an audit report produced by SGS that covers business licences, certifications, production and quality control systems. The page describes no testing of individual batches.

So an audit tells you about the company. A COA in a listing is the supplier’s document, to be checked like any other. To judge a supplier before a first order, use our checklist for vetting a manufacturer.

What origin tells you, and what a test tells you

A country label is too coarse to judge a batch. The FDA’s green list, the GLP-1 ingredient makers that met its criteria for exclusion from detention, includes 12 firms in China. The same alert reports that 21% of the 48 GLP-1 ingredient sites the FDA evaluated were noncompliant, without a breakdown by country. Neither fact tells you which plant made your batch, or how it was stored since.

A test answers the questions that matter for one vial. Start with identity by LC-MS, which compares the measured mass with the expected mass, and content per vial, which gives mg of peptide against a reference standard. Purity by HPLC comes next. For where to send samples, see peptide testing for products from China.

What HK Analytical does

Our lab is in Hong Kong. Samples from mainland China reach it by cross-border courier. Declare the contents accurately and follow the courier’s rules; we send the sample form on request. One order can include identity (LC-MS), purity (HPLC), content per vial, blind GLP-1 identification, endotoxin (LAL), Sterility (USP <71>, 14 days), residual solvents, counter-ion, water content and vial-to-vial consistency, in any mix per sample. Results within days of receipt. Sterility (USP <71>, 14 days) is the one test that takes 14 days, because the method incubates for 14 days.

Every number in the report comes with its raw data, in a signed record you can check on hkanalytical.com/verify. The report also states how the client is related to HK Analytical. How it works shows each step, and you can request a quote.