Synthetic Peptides HS Code: How to Classify Peptide Imports

There is no single HS code for synthetic peptides. At the six-digit international level, most synthetic peptides are classified under heading 2937 — hormones and polypeptide hormones, including chain modified polypeptides used primarily as hormones — with 2937.19 and 2937.90 as the most common subheadings. In the United States that becomes a 10-digit HTSUS number, and peptides put up as finished drugs or cosmetics move to Chapters 30 or 33 instead.

Because the answer depends on the molecule, the dosage form, and the packaging, no vendor can hand you one code that fits every product.

What HS heading applies to synthetic peptides?

Chapter 29 of the Harmonized System covers organic chemicals. Heading 2937 covers hormones, prostaglandins, thromboxanes, leukotrienes, and their derivatives and structural analogues — a description the HS explicitly extends to chain modified polypeptides used primarily as hormones.

• 2937.11 — insulin and its salts
• 2937.12 — pituitary, hypothalamic, and similar hormones and their derivatives
• 2937.19 — other polypeptide hormones, a frequent landing spot for synthetic peptide hormones such as GHRH analogues and GLP-1-type compounds
• 2937.50 — prostaglandins, thromboxanes, and leukotrienes
• 2937.90 — other, including structural analogues that do not fit the hormone subheadings

Peptides that are not used primarily as hormones do not automatically land in 2937. Depending on structure, they can be classified in 2934.99 (other heterocyclic compounds) or another Chapter 29 heading.

That is why the phrase peptides hs code rarely has one clean answer: two vials with similar labels can sit in different headings.

How US HTS codes differ from the 6-digit HS code

The HS is a six-digit system maintained by the World Customs Organization and used by more than 180 countries. The United States extends each subheading to ten digits in the Harmonized Tariff Schedule of the United States, and only the 10-digit number drives the actual duty rate at the border.

So "2937.19" tells you where a peptide sits internationally, while the full 10-digit line is what an importer files on an entry summary. Always file at the 10-digit level and keep the reasoning on file.

Classification by product form

The table below shows how the same peptide can fall under different headings depending on how it is imported. Treat the HTS examples as illustrations, not as a substitute for checking the current tariff schedule or a CBP ruling.

Product as imported	Likely HS heading	Commonly cited US HTS line	Why
Bulk synthetic peptide hormone or analogue	2937	2937.19.0000 / 2937.90.90	Separate chemically defined compound used primarily as a hormone
Synthetic peptide that is not hormonal	2934 or other Chapter 29 heading	2934.99.90	Chapter 29 classification follows chemical structure
Peptide put up in measured doses for therapy	3004	Varies by subheading	Chapter 30 covers medicaments put up for therapeutic use
Peptide in a finished cosmetic or skincare product	3304	3304.99.50	Chapter 33 covers beauty and skin care preparations
Peptide supplied as a diagnostic or lab reagent kit	3822	3822.00.5090	Only when the product actually functions as a reagent

Cosmetic peptides, research peptides, and drugs are classified differently

A raw peptide sold as a bulk ingredient is still an organic chemical, so it usually stays in Chapter 29. The cosmetic peptide hs code only shifts to Chapter 33 once the peptide is blended into a finished lotion, serum, or cream marketed as a cosmetic.

Research peptides labeled "not for human consumption" are a gray area. Customs classifies the article in front of it, not the disclaimer on the label. If the same vial is put up in measured doses for a therapeutic use, Chapter 30 becomes the stronger fit.

One more point worth clearing up: are all peptides synthetic? No. Many peptides are natural, some are semi-synthetic, and heading 2937 covers hormones whether they are natural or reproduced by synthesis, so "natural" does not automatically mean a different code.

Duties, tariffs, and de minimis

Base duty rates on Chapter 29 chemicals are often low or free in the United States, but the base rate is not the whole bill. Section 301 tariffs have applied to many Chinese-origin chemical and pharmaceutical inputs since 2018, and additional tariff actions since 2025 have changed the math repeatedly.

• Check the current USTR Section 301 lists and any newer tariff action before you price a shipment.
• The $800 de minimis exemption has been narrowed or eliminated for many shipments since 2025, so small peptide orders that once cleared informally may now require a formal entry.
• Antidumping, countervailing duty, and FDA admissibility questions are separate from the HS code and can stop a shipment even when the code is right.

Common classification mistakes

Misclassification is the fastest way to turn a routine entry into a penalty case. US importers are legally required to exercise "reasonable care" when classifying goods, and CBP can assess penalties, liquidated damages, or seizure when a code appears to have been chosen to lower the duty.

1. Picking a code for the rate. Selecting a line that carries less duty than the product warrants is classic misclassification.
2. Assuming every peptide is 2937. Non-hormonal peptides often belong elsewhere in Chapter 29.
3. Ignoring the dosage form. Medicaments and cosmetics are classified in Chapters 30 and 33.
4. Treating a correct code as legal clearance. A correct HS code does not make an unapproved drug legal, which is the real issue behind searches like is hs peptides legit.
5. Trusting marketing instead of documents. A discount such as a modern research peptides coupon code says nothing about classification, purity, or admissibility.

How to confirm your HS code

The reliable path is a written answer from the people who decide, backed by a complete technical file.

• Request a binding ruling from US CBP through the eRulings system; it is legally binding for the merchandise described.
• Give your customs broker the full package: chemical name, CAS number, sequence, purity, and the exact form as imported.
• Confirm the FDA pathway separately — bulk drug substance, compounded preparation, cosmetic ingredient, or research chemical.
• Review the entry after it liquidates and keep the classification rationale on file for future shipments.

Talk to a licensed customs broker and, where human use is involved, a healthcare professional or regulatory consultant before relying on any single number.

COMMON QUESTIONS

Frequently Asked Questions

What is the HS code for synthetic peptides?

Most synthetic peptides fall under HS heading 2937, with 2937.19 covering polypeptide hormones and 2937.90 covering other analogues and derivatives. Peptides not used primarily as hormones can be classified in other Chapter 29 headings, and peptide products put up as medicaments or cosmetics move to Chapters 30 or 33.

Is there a duty-free HS code for peptides in the United States?

Many Chapter 29 chemical lines carry a general duty rate of zero in the HTSUS, but Chinese-origin goods can face Section 301 tariffs on top of that base rate. Because tariff actions have changed repeatedly since 2018, verify the current 10-digit line and any applicable USTR lists before you price a shipment.

Do cosmetic peptides use the same HS code as injectable peptides?

A bulk cosmetic peptide ingredient is usually classified as an organic chemical in Chapter 29, often under heading 2937. Once the peptide is part of a finished cosmetic preparation, the product shifts to Chapter 33, most commonly 3304. Injectable or otherwise therapeutic peptide products put up in measured doses are classified in Chapter 30.