Peptide Handling
Traveling With Peptides: Keeping Vials Stable in Transit
Travel is a temperature problem. Dry powder tolerates it; a solution may not, and the coolant meant to protect a vial is one of the commonest ways to freeze it. This page sets out what published labels say about time out of the refrigerator, what public-health cold-chain guidance says about packing refrigerated products for transport, and what a car does to the temperature inside it. Research-material handling education only.
The short answer
- Dry powder is the travel-friendly form. NIBSC states that dry peptides are stable at room temperature for days to weeks; keep them sealed, dry and out of light.
- A solution follows its label, if it has one. Labels for peptide products run from refrigeration at all times to room temperature with the refrigerator forbidden. Unlabeled research solutions have no tested allowance.
- Freezing is the common failure. Frozen gel packs can freeze a vial even when they look like they are thawing. Use conditioned coolant and an insulating barrier.
- Never leave it in a parked car. A car’s interior rises by about 22 °C within an hour on a sunny day, most of it in the first 30 minutes.
- Record the temperature. A minimum/maximum thermometer turns “it was probably fine” into a fact.
Dry powder or solution: which one is travelling?
The answer changes everything else on this page. A lyophilized (freeze-dried) peptide has had its water removed, and NIBSC’s handling guidance describes dry peptides as stable at room temperature for days to weeks, and warns that moisture contamination greatly decreases long-term stability — which is why a sealed vial should stay sealed until it is back in storage. A reconstituted peptide is a solution, and solutions degrade faster; the storage reference guidance cited on our peptide storage page does not recommend keeping peptides in solution at all where it can be avoided.
How long can a peptide solution be out of the refrigerator?
There is no general figure, and the published labels show why. Four peptide products, four different rules — one of them forbids the refrigerator outright. Where they address freezing, they agree: a frozen product is not used.
| Product | Labeled temperature | What else the label says |
|---|---|---|
| Teriparatide (FORTEO) pen | 2–8 °C “at all times except when administering” | “Do not freeze. Do not use FORTEO if it has been frozen.” Recap the pen to protect it from physical damage and light. |
| Tirzepatide (MOUNJARO) single-dose pen or vial | Refrigerated; “if needed” unrefrigerated at up to 30 °C for a total of 21 days | “Do not freeze … Do not use if frozen.” Protect from heat and light; keep in the original carton. |
| Tesamorelin (EGRIFTA WR), mixed with Bacteriostatic Water | 20–25 °C — “Do not freeze or refrigerate” | Discard 7 days after mixing. |
| Insulin vials and pens (FDA emergency guidance) | Unrefrigerated at 15–30 °C (59–86 °F) for up to 28 days | Do not use insulin that has been frozen; keep it away from direct heat and out of direct sunlight. |
Sources: FDA labeling for FORTEO and MOUNJARO (openFDA, effective August 2026); EGRIFTA WR labeling (DailyMed); FDA, Information Regarding Insulin Storage (content current as of 28 September 2026). All read or re-read 14 October 2026.
Each allowance belongs to that specific formulation. None of them transfers to a different product, and none of them describes an unlabeled research solution — for that, no tested allowance exists, so the honest plan is to hold it at its storage condition throughout and keep a record.
Packing for the trip: what cold-chain guidance asks for
The most detailed public guidance on moving refrigerated injectables is CDC’s Vaccine Storage and Handling Toolkit (July 2026), written for clinics transporting vaccines. Its principles apply to any refrigerated vial; CDC states that improper packing for transport is as risky as a failed storage unit.
| Element | What the guidance says |
|---|---|
| Container | An insulated container built for temperature-sensitive products. CDC tells clinics not to use commercially available soft-sided food or beverage coolers, which are mostly poorly insulated. |
| Coolant | Phase-change packs conditioned to 4–5 °C, or conditioned frozen water bottles. CDC warns that frozen gel packs “can still freeze” refrigerated products “even if they are conditioned or appear to be ‘sweating.’” |
| Barrier | A layer of bubble wrap or corrugated cardboard between the coolant and the vials — CDC asks for enough to form two layers. Its rule for diluents is absolute: never freeze them, not even in transit. |
| Thermometer | A continuous temperature monitor that records minimum and maximum, ideally a data logger accurate to ±0.5 °C, with its probe beside the vials. Note the time and temperature when packing. |
| Placement | In a vehicle, the passenger cabin, not the trunk or a truck bed, which CDC says “may be too hot or too cold”; out of direct sunlight; never left in a parked car. |
| Handling | Vials in their original packaging, protected from drops, shocks and vibration, and kept out of light. |
Source: CDC, Vaccine Storage and Handling Toolkit, July 2026, Section Six (Non-Emergency Vaccine Transport), pages 29–32.
Why a parked car is the riskiest part of the trip
A Stanford study measured the inside of a dark sedan on 16 clear days with outside temperatures from 72 to 96 °F (about 22–36 °C). Whatever the starting temperature, the interior rose by about 40 °F (about 22 °C) over the hour, 80% of that rise came in the first 30 minutes, and even on the coolest day the car reached 117 °F (47 °C). Leaving the windows open 1.5 inches did not slow it (McLaren, Null & Quinn, Pediatrics 2005, PMID 15995010).
That is well above the 30 °C ceiling in the most permissive label in the table above, and it happens on a mild day. An insulated container slows the climb; it does not stop it. The vial goes where you go.
After an excursion: frozen or overheated
Freezing has the clearest answer. FORTEO and MOUNJARO labeling both say not to use the product if it has been frozen, and FDA says the same of insulin. A solution that froze in transit is the case those labels exclude. Heat is judged against a label’s stated room-temperature allowance where one exists. Unlabeled research material has nothing to judge against, which is the practical reason to carry a minimum/maximum thermometer: it is the only way to know whether an excursion happened at all. The checks for a vial’s contents are on our vial coring and inspection page.
What this page does not cover
Whether a given material may be carried through airport security, on a particular airline, or across a border is set by the screening authority, the airline and the destination’s customs authority. Those rules differ by country and by product and change over time; this page makes no statement about them. Check with those authorities directly before travelling.
What about the bacteriostatic water?
Bacteriostatic Water for Injection is labeled for controlled room temperature and does not need a refrigerator — the detail is on does bacteriostatic water need to be refrigerated. If it shares an insulated container with refrigerated items, CDC’s advice for room-temperature diluents applies: chill it beforehand so it does not warm the container, and keep it from freezing. Medibact supplies USP-grade bacteriostatic water produced in an FDA-registered U.S. facility, in the 30 mL multiple-dose format, for research use only.
Where this sits in the rest of the reference
FAQ
How do you travel with peptides?
As a temperature problem first. Dry (lyophilized) powder tolerates a trip far better than a solution: NIBSC states that dry peptides are stable at room temperature for days to weeks. A reconstituted solution has no general rule — FDA labels for peptide products range from refrigeration at all times to room temperature with a refrigerator forbidden — so a labeled product follows its label, and unlabeled research material should be treated as having no tested allowance. Pack with an insulated container, conditioned coolant behind a barrier so nothing freezes, and a thermometer that records the minimum and maximum.
Can you fly with peptides?
What may be carried through security, on a particular airline or into a particular country is decided by the screening authority, the airline and the destination’s customs authority, and this page does not answer that; check with them before travelling. What it covers is keeping a vial stable on the way: insulation, coolant that cannot freeze it, a temperature record, and keeping it in your own hands rather than in a vehicle or a place you cannot see.
Do reconstituted peptides need to stay cold while travelling?
It depends entirely on the product. The FORTEO label requires 2–8 °C at all times except during use; the MOUNJARO label allows a single-dose pen or vial up to a total of 21 days at no more than 30 °C; the EGRIFTA WR label requires the mixed solution to be kept at room temperature and never refrigerated. An unlabeled research solution has no label to state an allowance, so the only defensible plan is to keep it at its storage condition and record the temperature.
Can I use ice packs for peptides?
Not frozen packs against the vials. CDC’s transport guidance for refrigerated products says frozen gel packs can freeze them even when the packs are conditioned or look like they are “sweating,” and recommends phase-change materials conditioned to 4–5 °C or conditioned frozen water bottles, with an insulating barrier such as bubble wrap between coolant and product. The FORTEO and MOUNJARO labels both say not to use a product that has been frozen.
Can peptides be left in a hot car?
A parked car is the worst place in the trip. In a Stanford study of a dark sedan on sunny days with outside temperatures of 72–96 °F (about 22–36 °C), the inside rose by about 40 °F (about 22 °C) within an hour, 80% of it in the first 30 minutes, and reached 117 °F (47 °C) even on the coolest day. Cracking the windows made no measurable difference.
What should I do if a vial froze or got hot on the way?
For a labeled product, the label decides, and freezing is the clearest case: FORTEO, MOUNJARO and FDA’s insulin guidance all say not to use a product that has been frozen. A heat excursion is judged against the label’s stated room-temperature allowance, if there is one. For unlabeled research material there is no tested allowance to compare against, so a recorded excursion is a reason to treat the material as compromised rather than to guess.
Does bacteriostatic water need to be kept cold when travelling?
No. Bacteriostatic Water for Injection is labeled for storage at controlled room temperature. If it travels in the same insulated container as refrigerated items, CDC’s advice for room-temperature diluents applies: chill it in advance so it does not warm the container, and keep it from freezing.
Is this medical or legal advice?
No. This page is research-material handling education drawn from published U.S. labeling and public-health cold-chain guidance. It contains no dosing, route or timing instruction and makes no statement about what screening, airline or customs rules permit. Medibact is not affiliated with Eli Lilly, Theratechnologies or any manufacturer named here.
Educational use only — not medical advice. This guide summarizes information reported in published research and community practice for educational purposes. It is not medical advice and not a recommendation to use any compound. Any doses, schedules, or combinations shown are examples of what has been reported, not instructions for you. Many peptides described here are research compounds that are not FDA-approved for the uses discussed and may be investigational or restricted. Effects, risks, and legal status vary; individual needs and results vary. Consult a qualified, licensed healthcare professional before making any decision. Do not use this content to diagnose, treat, or dose yourself.