Retatrutide Vial Sizes, Price per mg and Identity (LY3437943)

Retatrutide comes in five vial sizes at Pepta Labs: 10 mg, 15 mg, 20 mg, 30 mg and 60 mg, each a sealed glass vial of lyophilized (freeze-dried) powder with its own product page. Every size carries the same identity: research code LY3437943, CAS 2381089-83-2, molecular formula C221H342N46O68 and a listed molecular weight of 4731.36 Da. This page sets out the sizes, the price-per-milligram arithmetic for each one and how the listing's identifiers compare with the FDA and PubChem registry records, checked on September 24, 2026.

What vial sizes does retatrutide come in?

Retatrutide is listed in five vial sizes: 10 mg, 15 mg, 20 mg, 30 mg and 60 mg. Each size is a separate listing with its own product page, price and stock status, and the largest label quantity is six times the smallest. Every vial contains one compound as a dry lyophilized solid.

Every retatrutide size with a live listing, ordered by size:

Prices are read from the catalog when this page loads; price per mg divides the single-unit price by the supplier-stated quantity. Multi-unit pack prices are shown on each product page.

Each product page shows the current price and stock. If a size is out of stock, the rows above and below it are the nearest sizes, or you can ask about restock timing through the contact page. All five sizes are also listed together on the category page.

How much is in a vial of retatrutide?

A retatrutide vial is labelled 10, 15, 20, 30 or 60 mg, and that label figure is the supplier-stated nominal quantity of lyophilized solid, not a measured content; vial fill-quantity testing is not claimed. A lyophilized peptide solid normally includes a counter-ion and some residual water alongside the peptide itself, so net peptide content is a separate figure from the label quantity. Net peptide content is not reported per listing and is not part of the HPLC and mass-spectrometry reporting. Our TFA vs acetate guide explains how the salt form changes that figure.

Vial labels identify the compound, quantity and research-use designation. They do not carry lot or batch numbers.

How is the price per mg worked out for each retatrutide size?

Price per milligram is the listed price divided by the total nominal milligrams in the listing. For a single vial, divide by the label quantity: the 10 mg price by 10 and the 60 mg price by 60. For a multi-vial listing, multiply the number of vials by the milligrams per vial first; a five-vial listing of 20 mg vials totals 100 mg nominal, so its listed price is divided by 100.

A multi-vial listing is one catalog option that contains several sealed vials of the same size, each labelled separately. Where a size offers one, it is chosen on the product page in place of the single vial and carries its own listed price; not every size has multi-vial listings. Prices are set per listing and can change, so run the arithmetic on each listing's current price rather than on a figure copied from elsewhere. A promo code entered at checkout applies to the order total, not to one listing's price per mg.

The catalog-wide price per mg table covers the other listings and does not include retatrutide, whose sizes are set out on this page. Other listings in the same category have their own size pages: tirzepatide vial sizes and cagrilintide 10 mg.

What is retatrutide, by identifier?

Retatrutide is the International Nonproprietary Name (INN) of a synthetic peptide amide registered under CAS 2381089-83-2 and the research code LY3437943. The FDA Global Substance Registration System (GSRS) records the same name as an INN and as the United States Adopted Name (USAN), lists the codes LY3437943 and LY-3437943, and carries the CAS number 2381089-83-2. The CAS number, formula and molecular weight also appear in the specification table on each retatrutide product page.

CAS numbers and molecular weights for the rest of the catalog are collected in the CAS number and molecular weight table, and the guide to research peptides explains how listings, identifiers and reports fit together.

Where is the code LY3437943 recorded?

LY3437943 is the research code recorded for retatrutide in the FDA GSRS record, which lists it both as LY3437943 and hyphenated as LY-3437943. It names the same substance as CAS 2381089-83-2, so a listing, analytical report or registry entry showing any one of the three identifiers (retatrutide, LY3437943 or 2381089-83-2) refers to one compound. Pepta Labs lists retatrutide under the full name "Retatrutide (LY3437943)" on every size.

Do the registry records agree with the listing?

The CAS number agrees everywhere: the listing, the FDA GSRS record and the PubChem depositor records all carry 2381089-83-2. The formula agrees with PubChem: the two PubChem depositor records we checked, which between them list the name, the CAS number and LY3437943, map to one computed compound record with the formula C221H342N46O68, the listing formula, and a molecular weight that rounds to 4731.

The FDA GSRS figures differ. The GSRS record marks its molecular formula and molecular weight as estimated, and both are lower than the listing values; the estimate matches the formula of the plain one-letter amino-acid chain as a free acid. That chain leaves out the methyl groups of the non-coded residues, the C-terminal amide and the lysine side chain that the GSRS systematic name spells out. We rebuilt the formula from the systematic name on September 24, 2026, and it comes to C221H342N46O68, the listing value. For identity checks, the listing formula and weight describe the full structure; the GSRS estimate describes the unmodified chain only.

Which salt form is retatrutide listed as?

The retatrutide listings do not state a salt form, and the listed formula C221H342N46O68 contains no counter-ion, so 4731.36 Da is the molecular weight of the peptide without any salt. FDA GSRS keeps a separate record, retatrutide sodium, for a sodium salt; no Pepta Labs listing states that form. Counter-ion content is not reported per listing. The TFA vs acetate guide explains why a counter-ion changes the weighed mass of a vial's solid but not the peptide's own formula.

What masses should a mass spectrum of retatrutide show?

Calculated from the listed formula, retatrutide has a monoisotopic mass of 4728.47 Da and an average mass of 4731.35 Da; the listing's 4731.36 Da agrees within the rounding of atomic weights. Electrospray spectra of a peptide this size normally show a series of multiply protonated ions rather than a single [M+H]+ peak, so the table gives the calculated m/z for four charge states.

Values are calculated, not measured: monoisotopic masses use C 12.000000, H 1.0078250319, N 14.0030740052 and O 15.9949146221, average masses use C 12.0107, H 1.00794, N 14.0067 and O 15.9994, and each ion adds one proton (1.00727646688) per charge. At about 4.7 kDa the monoisotopic peak is a small member of the isotope cluster, so the tallest peak in each charge state sits above the monoisotopic m/z; at low resolution the average-mass column is the closer guide. The expected mass table shows the same calculation for other listed compounds, and HPLC vs mass spectrometry explains what each test answers.

Is the chemical identity the same for every vial size?

Yes. Vial size changes only the label quantity, not the compound, so the CAS number, molecular formula and molecular weight are the same for the 10 mg vial as for the 60 mg vial. On September 24, 2026, all five retatrutide product pages showed CAS 2381089-83-2, C221H342N46O68 and 4731.36 Da. The mass-spectrometry result on the analytical report is the direct identity check.

How is a retatrutide order paid?

Retatrutide is not paid through the online card checkout. The order is reserved, and the payment options are listed on the next page and in the confirmation email. A cart that contains retatrutide is completed this way as a whole. Processing begins once payment is received.

Orders are placed from a free account with a confirmed email, so every order traces back to a real customer. Buyers must be 21 or older, and Pepta Labs ships to United States addresses only.

Is there an HPLC and mass spectrometry report for retatrutide?

Yes. Each retatrutide listing shows its reported RP-HPLC purity, and the analytical report behind that figure is sent by email on request, before you order if you want to see it first.

Independent third-party HPLC purity analysis and mass-spectrometry identity confirmation, commissioned through the purchasing group on a sampled production run from the source. Pepta Labs does not test in-house. Sterility, endotoxin or LAL, potency, pharmaceutical-grade, cGMP, contaminant-panel and vial fill-quantity testing are not claimed. Because vials carry no lot or batch number, the report is a production-run report, not a lot-specific certificate for the vial you receive.

To request it, use the report request form or email support@peptalabs.com with the size you are looking at. The COA verification guide walks through each line of a report, and the quality page explains how testing is commissioned.

How is retatrutide shipped and stored?

Retatrutide ships to US addresses as a dry lyophilized powder in a sealed vial at ambient temperature, and shipping is free. Most orders ship the next business day. Processing and delivery times are estimates, not guarantees. Temperatures and handling for sealed vials are in the peptide storage guide, and return conditions are in the returns terms.

Frequently asked questions

What sizes does retatrutide come in?

Pepta Labs lists retatrutide in five vial sizes, 10 mg, 15 mg, 20 mg, 30 mg and 60 mg, each a sealed vial of lyophilized powder on its own product page. The largest label quantity is six times the smallest, and stock is shown on each product page.

Where is the price for each retatrutide vial size?

Each size's current price is on its own product page, together with any multi-vial listings for that size, and the size table on this page links every size with a live listing. Price per milligram is the listed price divided by the milligrams in the listing, for example the 30 mg single-vial price divided by 30.

What is LY3437943?

LY3437943 is the research code for retatrutide, recorded in the FDA GSRS record both as LY3437943 and as LY-3437943. It identifies the same substance as CAS 2381089-83-2.

What is the CAS number of retatrutide?

The CAS number of retatrutide is 2381089-83-2. The same number appears on every Pepta Labs retatrutide listing, in the FDA GSRS record and in PubChem depositor records.

What is the molecular formula and weight of retatrutide?

Retatrutide is listed with the molecular formula C221H342N46O68 and a molecular weight of 4731.36 Da; the monoisotopic mass calculated from that formula is 4728.47 Da. The FDA GSRS record shows a lower estimated formula and weight that matches the unmodified amino-acid chain only.

All products are supplied for laboratory research use only and are not for human or animal use.