How prices are compared

Every price figure on this site is arithmetic on the prices we publish. This page says which listings enter the arithmetic, how a market median is computed, how a store's price position is computed, and how the price history is built. Nothing is weighted, adjusted or overridden by hand.

Which listings are compared

A listing enters the per-milligram comparison when all of the following are true:

• It is a single vial, not a multi-vial pack or kit.
• It is one compound. On a blend's own page, premixed vials of that blend count too, priced by the total peptide in the vial.
• Its size is stated in milligrams.
• Its size and its price were read from the listing itself, not from a "from" price, a starting price or a range.
• The price is visible without logging in.
• It is in stock.

Everything else still appears on the page, in its own labeled section, and stays out of every figure on this page. Capsules, sprays, solutions, strips and topicals are listed separately because their units do not convert to a vial's milligrams. Prices behind a login are recorded as walled rather than guessed.

One number per store

A store that lists the same size six times counts once. Its value is its lowest comparable price per milligram at that size. Without this rule a store with a long catalog would outweigh the rest of the market by listing more, not by charging less.

The market median

The market median is computed per compound and per vial size. Take every store's number for that size, sort them, and take the middle one. With an even count, average the two middle values. A median is published only when at least three stores have a comparable listing at that size.

An illustration with made-up numbers. Five stores sell a 10 mg vial at $4.00, $5.00, $5.50, $6.20 and $9.00 per milligram. The median is $5.50. A sixth store joins at $7.00, so the two middle values are now $5.50 and $6.20, and the median is $5.85. The $9.00 store moved nothing, which is the point of a median.

Why size matters

Price per milligram falls as vial size rises. A 30 mg vial will almost always look cheaper per milligram than a 5 mg vial of the same compound, from the same store, on the same day. So comparisons are made within a size, never across sizes. Where a compound page shows one market figure for the whole compound, it uses the compound's most-listed vial size and says which size that is.

A store's price position

A store's price position compares its prices with the rest of the market, one product at a time:

1. Take each compound and size where the store has a comparable listing and at least three other stores do too.
2. Compare the store's lowest price per milligram at that size with the median of the other stores' lowest prices at that size. The result is a percentage above or below.
3. The store's price position is the median of those percentages.

A position is shown only when the store has at least five such comparisons. Below that, the profile reads "Not enough comparable listings." The store's own prices are never part of the median they are measured against.

Another illustration. A store is 12% below the market on one product, 8% below on a second, 3% below on a third, 4% above on a fourth and 15% above on a fifth. Sorted, the middle value is 3% below, so the store's position is 3% below market. The one product where it charges 15% more does not drag the figure, and the one where it charges 12% less does not flatter it.

Price over time

Prices are captured on the dates shown on each row. Each capture records, for every compound and size with at least three comparable stores, the market median, the lowest store price and the store count. The series runs from the first capture we hold, August 26, 2026, and grows by one point each time prices are updated.

Every point in the series is computed under the rule on this page, including captures that predate it. The rule was unified on October 24, 2026. Before that date, different pages computed the middle value in different ways, so a figure a page showed in September can differ slightly from the point now plotted for that date. The plotted point is the one computed consistently.

What the figures do not say

A low price per milligram says nothing about what is in the vial. Testing evidence is a separate record, kept on the vendor page and never mixed into any price figure. A store's price position is a description of its prices, not a judgment of the store.

Corrections

If a figure on a page does not follow the rules above, write to corrections@peptidedecoding.com with the page and the figure. The arithmetic is tested on every build, so a reproducible mismatch is a bug and gets fixed.

Changes to this page

October 25, 2026. First version.