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How long do lyophilized peptides last? Four makers' figures
Shelf-life figures for lyophilized peptides as sb-PEPTIDE, GenScript, peptide.com and JPT state them, by temperature, and why none is an expiry date.
How long lyophilized peptides last depends on the temperature and on whose figure is quoted. Manufacturers’ pages give several days to months at room temperature and, on GenScript’s figure, several years at -20 °C for most peptides. None of these is an expiry date: GenScript says stability depends on sequence, and sb-PEPTIDE says it does not define stability for custom peptides.
This is an evergreen explainer with no news peg. This desk read the handling pages of sb-PEPTIDE, GenScript, peptide.com and JPT on 16 October 2026. In the text this desk read, none of the four carries a date. The conditions themselves are covered in the site’s storage comparison; this post covers the durations stated for them.
How long do lyophilized peptides last at each temperature?
Each cell is the manufacturer’s own wording, as read. “No figure” means the text this desk read gives none for that condition, not that the manufacturer has never stated one.
| Source | Room temperature, powder | About 4 °C | -20 °C, powder | -80 °C | In solution |
|---|---|---|---|---|---|
| sb-PEPTIDE | “Several days to weeks” in initial packaging | An option, no figure | Below -20 °C or -80 °C past 4 weeks; no figure | As -20 °C | “Globally accepted”: 1-2 weeks at +4 °C, 3-4 months at -20 °C, 1 year at -80 °C |
| GenScript | No figure | No figure | Most stable “for several years”, away from bright light | No figure | “Very limited”, much shorter than lyophilized |
| peptide.com | “Weeks to months”, away from heat, light, moisture | No figure | Longer-term storage; no figure | No figure | Not “more than a few days”; freeze |
| JPT | Not recommended for long periods; no figure | “A few weeks to several months” | Preferred; no figure (powder generally “several months to years” if stored correctly, no temperature given) | Preferred; no figure | No figure |
The ranges are kept in the manufacturers’ words. “Several years” is not converted into a number here, because no page read supplies one.
What kind of statement is each figure?
General guidance, in every case. sb-PEPTIDE’s solution figures are not its own data: it introduces them as what is “globally accepted” for peptides in solution. Its own statement about its products is narrower. The stability of custom peptides, it says, is not defined by sb-PEPTIDE and can be assessed on request, and it offers stability studies.
GenScript’s “several years” comes with its own qualifier, that the stability of each peptide is unique and depends on its sequence. JPT ties its fridge range to structure and storage conditions. peptide.com notes that degradation in solution is sequence dependent and names the reactions: oxidation of Cys, Met and Trp, and deamidation of Gln and Asn. sb-PEPTIDE lists Asn, Gln, Cys, Met, Trp and Tyr as residues that tend to be less stable in solution.
Why is a shelf-life figure not an expiry date?
Because an expiry date, in the regulated sense, comes from testing. For drug products, 21 CFR 211.137 requires an expiration date determined by appropriate stability testing, related to the storage conditions stated on the labeling. That section is cited here only as a definition. It says nothing about research-use peptides or these four vendors.
None of the four pages read offers a lot expiry. In the text this desk read, the only lot-specific route is sb-PEPTIDE’s stability study on request. What a certificate of analysis does record, and what each line ties to, is set out in the site’s guide to reading a COA. Water matters to shelf life too, and the Karl Fischer line reports it as measured at the time of testing.
Frequently asked questions
How long do lyophilized peptides last at room temperature?
Two of the four manufacturer pages this desk read give a range. sb-PEPTIDE says lyophilized peptides can be kept in their initial packaging for several days to weeks. peptide.com says weeks to months, away from heat, light and moisture. JPT says room temperature is not recommended for long periods and gives no duration. GenScript’s text read gives no room-temperature figure.
How long do peptides last in the freezer?
GenScript says most lyophilized peptides are stable for several years at -20 °C, away from bright light, and adds that stability depends on sequence. sb-PEPTIDE recommends -20 °C or colder and peptide.com recommends -20 °C for longer storage, neither giving a duration for powder. JPT prefers -20 °C or -80 °C and, in the text read, attaches no number to either.
How long are peptides good for after reconstitution?
Much shorter than as powder, on the pages that address it. sb-PEPTIDE cites a figure it calls globally accepted: 1-2 weeks at +4 °C, 3-4 months at -20 °C and 1 year at -80 °C. peptide.com says peptides should not be stored in solution more than a few days. GenScript calls the shelf-life of peptides in solution very limited. This is lab-handling guidance only.
Do lyophilized peptides need to be refrigerated?
Not for short holding, according to sb-PEPTIDE and peptide.com, which both allow room temperature for a limited time. For anything longer, the pages that recommend a condition name the freezer rather than the fridge, apart from JPT’s fridge range. sb-PEPTIDE sets the line at 4 weeks. JPT gives the fridge a few weeks to several months and suggests a freezer beyond a few months.
Every figure above is a manufacturer’s general statement about research material, not a result for any sequence or lot. Research peptides are supplied for laboratory research use only; nothing here is a protocol for use, and no compound discussed is intended for human consumption. A stated range is a claim until a stability study puts a number to it.