Research peptides run $25–$150 per vial, about $3–$15 per mg. See what drives price, where custom synthesis hits $2,000–$8,000, and when not to buy.
Research-grade peptide reference materials generally run $25 to $150 per vial at the common 5 mg and 10 mg fill sizes, which works out to roughly $3 to $15 per milligram. Short, well-established sequences sit at the bottom of that band; long or difficult sequences, and anything sold with a ≥99% purity spec plus third-party analytical documentation, sit at the top. Custom synthesis is a different market entirely — expect $2,000 to $8,000 for a first-time 100 mg custom order, driven by a per-residue cost of roughly $80 to $250 at small scale. Below is what those numbers are actually buying, where the money leaks, and the situations where the correct decision is not to buy at all.
Vial price is a bad comparison unit. Fill size varies, and a $45 vial and a $60 vial are frequently the same material at different weights.
The spread between the cheapest and most expensive vial of a nominally identical sequence is routinely 3x to 5x. That gap is not arbitrary. It tracks purity spec, whether the certificate of analysis is lot-specific or generic, whether identity was confirmed by mass spectrometry or only inferred, and how much of the manufacturer's yield was sacrificed to preparative purification.
Peptide cost is dominated by synthesis chemistry, not by branding. Four variables move it more than anything else:
Sequence length. Solid-phase synthesis couples one residue at a time, and each coupling step carries a small failure rate. At 99.5% efficiency per step, a 10-mer finishes at about 95% crude yield; a 40-mer finishes near 82%. Longer sequences require more purification passes to hit the same final spec, and each pass throws away material. A 33-residue sequence can cost 4x to 6x more per milligram than an 11-residue one at equal purity.
Difficult residues. Cysteine-containing sequences requiring disulfide bridge formation, sequences with multiple arginines, and anything requiring N-terminal modification or C-terminal amidation add 20% to 60% to synthesis cost.
Purity spec. Moving a lot from a 95% spec to a 99% spec typically means one or two additional preparative HPLC passes, with 20% to 40% yield loss each time. That is why the price delta between a 95% and a 99% listing is often 30% to 70%, not a few dollars.
Analytical documentation. A lot-specific COA with an HPLC chromatogram, an MS spectrum showing the expected molecular ion, and water content by Karl Fischer costs the supplier real money to produce — a single outsourced HPLC-MS characterization runs $75 to $250 per sample. Amortized across a 500-vial lot that is well under a dollar per vial. Amortized across a 40-vial lot it is $2 to $6 per vial. Small-lot suppliers who publish full documentation are carrying a genuine cost, and it shows in their pricing. More detail on what a defensible certificate contains is on the quality page.
A cheap vial with no lot-specific certificate is not cheaper material. It is unverified material with the verification cost transferred to the buyer, at roughly $75–$250 per sample to close the gap.
Landed cost per usable milligram is the number worth tracking, and it includes several line items the product page never shows.
Add these up and a $6.00/mg vial frequently lands at $9 to $13 per usable milligram.
Volume discounts are real but they plateau faster than most buyers expect. Typical structure:
Beyond roughly 100 units the remaining cost is raw amino acid derivatives, resin, solvent, and labor — none of which compress much further. A buyer chasing another 5% past that point is usually trading it for longer lead times, since large orders often move from stock to made-to-order with a 3 to 6 week turnaround instead of same-week shipping. Tiering and minimums are documented on the wholesale page.
Lyophilized peptide powder held at −20 °C in a sealed vial commonly carries a 24 to 36 month shelf life, and at −80 °C often longer. That matters for bulk math: a 24-unit order that will be consumed over 30 months is a legitimate use of a volume discount. A 100-unit order against a 6-month program is not a discount, it is prepaid waste.
Several situations where the honest answer is that this purchase should not happen:
The application requires a pharmacopeial or certified reference standard. USP and EP reference standards cost $300 to $1,400 per unit and carry metrological traceability that research-grade material does not. If a method validation, a regulatory filing, or an accredited-lab SOP calls for a certified standard, RUO material is not a lower-cost substitute — it is the wrong material, and the finding will surface during audit. Buying it wastes both the vial cost and the analyst time.
The application is clinical, human, veterinary, or food-related. These materials are supplied for laboratory research use only, with no other authorized application. That constraint is not a formality that pricing can work around; see research use only and the disclaimer.
No −20 °C storage is available. A $60 vial held at ambient temperature is a depreciating asset with an unknown depreciation rate. Buying material that cannot be stored to spec converts a hard cost into an unquantifiable one, and any downstream analytical result inherits that uncertainty.
A single vial is needed once. When shipping and handling are 50%+ of the order, the effective cost per milligram roughly doubles. Consolidating with a colleague's order, or waiting until two or three items are needed, is straightforwardly better economics.
Price is the only selection criterion. The cheapest listings in this market frequently ship with a generic COA — one document reused across every lot, with no batch number tying it to the vial received. That document has no analytical value. A buyer who cannot verify lot traceability and has no budget for independent confirmation is not saving 40%; they are buying an untested white powder at a discount. Comparative notes on supplier documentation practices are collected in the high purity peptides review.
The quantity needed is under a few milligrams and the sequence is unusual. Custom synthesis minimums make small unusual orders brutally inefficient — a 5 mg custom order can still carry a $1,500 to $2,500 setup floor, landing above $300/mg. Sourcing an existing catalog analog, or redesigning the experiment around available material, is often the cheaper path.
Normalize before comparing. Three questions settle most quote comparisons:
1. Price per milligram at the stated purity, not price per vial — and confirm the purity method (HPLC area percent at a stated wavelength, typically 220 nm, is the norm; a bare "98%" with no method is not a spec).
2. Is the COA lot-specific? Check that the batch number on the certificate matches the vial label, that a chromatogram is attached, and that an MS spectrum confirms the expected molecular weight within a stated tolerance.
3. What is the total landed cost, including shipping mode, cold packs, and any handling surcharge, divided by the milligrams actually received?
A supplier quoting $8.50/mg with a lot-matched COA and MS confirmation is frequently cheaper in practice than one quoting $5.00/mg with a generic certificate, once a $150 verification test and a 2-week schedule risk are priced in.
For a lab standing up a modest reference-material inventory, realistic first-year numbers:
Consolidating those three orders into one saves $70 to $150 in shipping. Moving from 12 vials to 24 with a 20% volume discount saves another $145 to $260 — but only if consumption over the next 24 to 36 months actually justifies the second twelve.
Questions about lot documentation, batch availability, or quote normalization for a specific sequence can go through contact.
Supplied strictly for in-vitro laboratory research by qualified researchers and institutions. Not a drug, food, cosmetic or dietary supplement. Not for human or veterinary consumption. Not evaluated by the FDA.
Purity, identity and lot number, documented for the exact vial you receive.