tesamorelin
Tesamorelin Listing Terminology Explained
A plain-language guide to the terms used in tesamorelin listings, covering vial mass, purity notation, lot numbers, and how to read pricing per unit.
Medically reviewed by Catherine Dumont, MD, physician and clinical researcher — Last reviewed
Catherine Dumont, MD is a physician with clinical and research training in endocrinology and growth hormone therapeutics, with post-graduate research in GHRH analog applications and growth hormone axis disorders.
Tesamorelin listing terminology explained means understanding the specific words and numbers a supplier uses to describe a vial before comparing it to another. Two listings can look similar at a glance and still describe very different products once the terminology is unpacked. Knowing what each field represents is the first step toward reading a listing accurately rather than skimming it.
Vial Mass and What It Actually Represents
The most prominent number on a tesamorelin listing is usually the vial mass, typically written in milligrams (mg). This figure states how much lyophilized (freeze-dried) material is sealed in the vial before any liquid is added. It says nothing about concentration on its own — concentration only exists after a vial is reconstituted with a diluent such as bacteriostatic water. A listing that says “5 mg” is describing dry mass, not a ready-to-use solution.
Some listings also express mass in micrograms (mcg) in smaller print, particularly when comparing across vial sizes. Since 1 mg equals 1000 mcg, a 5 mg vial and a 5000 mcg vial describe the identical quantity of material, just in different units. Confusing the two units is one of the most common misreadings of a listing.
Purity Notation
Purity is often listed as a percentage, such as “>99%” or “98%+,” and refers to the proportion of the labeled compound relative to other substances present in the lyophilized powder, as determined by the testing method a supplier references (commonly HPLC). This notation describes the material itself, not the reconstituted solution, and it is a separate figure from vial mass. A listing that omits a purity figure or a testing method reference is providing less verifiable information than one that cites both.
Lot Numbers and Certificates of Analysis
A lot number (sometimes called a batch number) identifies which production run a vial came from. Reputable listings pair a lot number with a certificate of analysis (COA), a document from a testing lab that reports purity and identity results for that specific lot. When a listing references a lot number without a corresponding COA, or when the COA on the page does not match the lot printed on the vial, the terminology is present but the documentation behind it is incomplete.
Reconstitution Terms and the Concentration Field
Reconstitution volume refers to the amount of diluent added to the lyophilized powder, typically measured in milliliters (mL) of bacteriostatic water. Concentration is the mass of compound divided by the volume of diluent used, expressed as mg/mL. This is where a listing’s terminology connects directly to arithmetic a reader can check.
For example, a 5 mg vial reconstituted with 2 mL of bacteriostatic water yields a concentration of 5 mg ÷ 2 mL = 2.5 mg/mL. On a U-100 insulin syringe, where 1 mL equals 100 units, that concentration means each unit drawn on the syringe corresponds to 2.5 mg ÷ 100 = 0.025 mg, or 25 mcg, per unit. Recomputing this from the two source numbers — vial mass and reconstitution volume — is how a reader verifies that a listing’s concentration claim is internally consistent rather than accepting it at face value.
The table below summarizes how these terms relate to one another.
| Term | What it measures | Typical unit |
|---|---|---|
| Vial mass | Dry compound sealed in the vial | mg or mcg |
| Purity | Proportion of labeled compound in the powder | % |
| Reconstitution volume | Diluent added to the vial | mL |
| Concentration | Vial mass ÷ reconstitution volume | mg/mL |
| Per-unit amount | Concentration ÷ 100 (on a U-100 syringe) | mg or mcg per unit |
Pricing Terminology
Listings price a vial as a whole, but comparing two listings by sticker price alone ignores mass. The more useful figure is price per mg, calculated by dividing the listed price by the vial’s mg content. A $150 vial listed at 5 mg works out to $30 per mg, while a $250 vial listed at 10 mg works out to $25 per mg — a lower per-mg figure despite the higher sticker price. Some listings display price per mg directly; when they don’t, dividing the two published numbers takes only a moment and prevents a sticker-price comparison from being misleading.
Shipping terms, such as whether a listing ships on ice or with a cold pack, and storage terminology, like “store lyophilized powder refrigerated” versus “reconstituted solution refrigerated,” are also worth reading carefully, since they describe handling requirements rather than the product’s identity.
Reading a Listing End to End
Putting these terms together, a complete listing should let a reader identify: how much compound is in the vial (mass), how pure it claims to be (purity, ideally with a COA), what lot it came from, and what the price works out to per mg. A listing missing several of these fields is not necessarily wrong, but it gives a reader less to verify. For sourcing that documents these fields consistently, some readers cross-reference a listing against a supplier’s own tesamorelin product page to see how the same terminology is presented there. For reconstitution math specifically, a calculator such as peptcalc.com can double-check concentration and per-unit figures independently of a listing’s own claims.
Summary
Tesamorelin listing terminology breaks down into a small set of recurring fields: vial mass, purity, lot number and COA, reconstitution volume, resulting concentration, and price per mg. Reading a listing well means checking that these fields are present, internally consistent, and expressed in units that can be cross-checked with simple arithmetic, rather than taking a single headline number at face value.