tesamorelin
How Tesamorelin Listings Disclose Expiration Dating
A guide to how research tesamorelin listings present expiration dating, lot numbers, and storage terms, and what a COA should confirm about stability.
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 listings disclose expiration dating in a handful of predictable places: the product page, the certificate of analysis (COA), and sometimes a separate lot lookup tool. How a listing presents this information, and whether the dates line up across all three, says a lot about how carefully a supplier tracks its own inventory.
What “expiration dating” actually means on a peptide listing
Expiration dating on a research peptide listing usually refers to one of two things: a manufacturer-assigned shelf-life date tied to a specific lot, or a general “use within X months of reconstitution” guideline. These are not the same claim. A lot-specific expiration date is tied to stability data or manufacturer specification for that batch. A general reconstitution guideline is a storage recommendation, not a lab finding. Listings that blur the two together, presenting a generic shelf-life estimate as though it were lot-tested data, are giving less information than they appear to.
A listing that discloses expiration dating clearly will separate these ideas: a printed or stated expiration date for the lyophilized (freeze-dried) vial as received, and separate guidance about handling after reconstitution with bacteriostatic water.
Where the date should appear
For a listing to count as disclosing expiration dating in a verifiable way, the date needs to show up in more than one place and those places need to agree.
- Product page: some listings state a shelf-life range (“24 months from manufacture”) rather than a fixed date, since the date depends on which lot ships.
- Certificate of analysis: this is where a specific date tied to a specific lot number should appear, alongside the test date and the analytical methods used.
- Physical vial label: the lot number and, ideally, an expiration or manufacture date printed on the vial itself.
When these three sources agree, a listing is disclosing expiration dating in a way that can actually be checked against what arrives. When a site only states a vague shelf-life range with no lot-specific COA date, there is no way to confirm the claim against the product in hand.
Reading the COA date fields
A COA for tesamorelin typically includes a test or issue date and, less consistently, a stated expiration or retest date for the batch. The test date tells you when the sample was analyzed, not how long the compound is expected to remain stable afterward. A COA dated recently is not the same as a COA that states an expiration window.
| COA field | What it tells you | What it does not tell you |
|---|---|---|
| Lot number | Which manufacturing batch the vial belongs to | Whether that lot matches what shipped to you |
| Test/issue date | When the sample was analyzed | How long the compound remains within spec afterward |
| Expiration/retest date (if present) | The manufacturer’s stated stability window for that lot | Stability under reconstitution or specific storage conditions |
| Storage conditions listed | Temperature/light handling assumed for the stated dating | Whether the seller’s own storage matched those conditions |
If a COA has no expiration or retest date field at all, the listing is relying on the product page’s general shelf-life claim, which is weaker evidence than a per-lot figure.
Lyophilized shelf life versus reconstituted stability
These two clocks run separately, and a listing that only discloses one is leaving out half the picture.
The lyophilized (powder) form, kept sealed and refrigerated or frozen as specified, is what the manufacturer’s expiration date typically applies to. Once bacteriostatic water is added, the compound is in solution, and stability data on lyophilized powder does not automatically transfer to the reconstituted state. A listing that discloses expiration dating well will note both: a date or window for the sealed vial, and separate storage guidance for the period after reconstitution.
Some listings describe reconstituted stability in terms of a maximum handling window under refrigeration rather than a fixed date, since the actual figure depends on storage conditions the seller cannot fully control after the vial ships. Describing that relationship qualitatively — cold, dark storage extending usable handling time relative to room-temperature storage — is more honest than printing a specific number with no batch-level testing behind it.
A worked example of tracking dating against concentration
Expiration dating interacts with reconstitution math because a vial nearing the end of its stated window is one where getting the concentration calculation right matters more, not less.
Take a 5 mg tesamorelin vial reconstituted with 2 mL of bacteriostatic water:
Concentration = 5 mg ÷ 2 mL = 2.5 mg/mL
Converting to mcg per mL: 2.5 mg/mL × 1000 = 2,500 mcg/mL
On a U-100 insulin syringe, where 1 mL equals 100 units, that works out to 25 mcg per unit (2,500 mcg ÷ 100 units). None of this arithmetic changes because a vial is near its expiration date — but a listing that discloses dating clearly, alongside accurate vial mg content, is what lets a researcher run this calculation with confidence in the inputs. A listing with vague or missing dating information undermines the reliability of every downstream figure, even if the arithmetic itself is simple. Readers working through reconstitution figures for the first time may find a general calculator, such as the one at peptcalc.com, useful for cross-checking concentration math independent of any single listing’s claims.
What a well-documented listing looks like versus a poorly documented one
A well-documented listing states the lot number, links or attaches a matching COA, and gives dating information for both the lyophilized and reconstituted states without conflating the two. A poorly documented listing states only a generic shelf-life range on the product page, provides a COA with no batch-specific expiration field, or displays a COA that cannot be matched to the lot number on the vial that ships.
The distinction matters because expiration dating is one of the few pieces of information on a listing that is checkable after the fact — the lot number on the vial either matches the COA or it does not, and the date either sits within the stated window or it does not. Suppliers that make this easy to verify, such as a this tesamorelin listing, are giving researchers a way to confirm the claim rather than simply asserting it. For a broader comparison of how tesamorelin pricing and cost breakdowns are presented across sellers, peer tesamorelin listing catalogs cover the cost side of the same sourcing questions.
Summary
Expiration dating on a tesamorelin listing is only useful when it is specific, lot-matched, and separated into lyophilized shelf life versus post-reconstitution handling guidance. A vague shelf-life range on a product page is not the same as a dated, lot-specific COA field, and listings that keep these distinct — and that let a buyer match the vial’s lot number to the COA in hand — are disclosing expiration dating in a way that can actually be verified rather than simply taken on faith.