How long does reconstituted Tesamorelin last?

What the 28 days is counting

The window in the table starts on the day you add water. It does not start on the day you first draw from the vial. A vial mixed, refrigerated, and then ignored for three weeks has spent three weeks of its 28 days regardless of whether the stopper was ever pierced.

This matters because people naturally think of a vial as "fresh" until they open it. That intuition comes from food. It does not apply here. The clock is tied to the moment the powder stopped being dry.

The practical consequence is that the mixing date belongs on the vial in ink, on the day you mix it. Nothing else in the process records that date for you. A vial with no date on it has an unknown position in its window, and there is no way to recover the information later by looking at the liquid.

Why room temperature costs so much

The refrigerated figure and the room temperature figure in the table are not close. One is 28 days and the other is 2 days. That gap is the single most useful thing on this page.

What changes is preservative effectiveness. Bacteriostatic water contains a preservative intended to suppress microbial growth in a container that will be entered more than once. That suppression is far weaker warm than cold. The 28 day figure assumes the vial spends its life in a refrigerator, not that it merely started there.

This site cannot tell you how to treat a vial that sat out, how much of the window a warm afternoon consumes, or whether a partially warmed vial is still usable. Those are clinical judgment calls and there is no medical review behind this page. What the numbers show is only the size of the difference between the two storage conditions.

Dry powder is the stable form

The third row of the table is the reason vials ship as powder. Unmixed and refrigerated, the powder holds for months to years, which is a different order of magnitude from anything the mixed vial offers.

That suggests a simple ordering principle: delay mixing. A 2 mg, 5 mg, or 10 mg vial sitting sealed in the fridge is not spending its window. The moment water goes in, it is.

For multi-vial purchases this is the whole storage strategy. Mix one, leave the rest dry. The vendor's own date on the unmixed powder is the limit on the dry side, and that date is the vendor's claim, not something this site can verify or extend.

What these numbers do not tell you

The windows here describe the container. They say nothing about what happens after an injection. We hold no reliable human pharmacokinetic data for Tesamorelin, so this site makes no claim about its half life, how quickly it clears, or whether it accumulates with repeated use. Anyone quoting such figures for this compound is not getting them from us.

The arithmetic this site does is concentration and volume. A 10 mg vial reconstituted in 2 mL and a 5 mg vial reconstituted in 1 mL are different concentrations, and the syringe reading for a given dose amount differs between them. That is a division problem with a verifiable answer. Duration in the body is not.

Keep the two separate. Storage window is a property of the vial on your shelf. Dosing interval is a clinical question, and this page does not answer clinical questions.

Handling that supports the window

The 28 day figure assumes ordinary careful handling. It is not a guarantee attached to the liquid regardless of what happens to it. A vial returned to the fridge promptly after each draw is the case the number describes.

Write two things on the vial: the mixing date and the water volume used. The date positions you in the window. The volume is what makes the concentration recoverable later, because 1 mL, 2 mL, and 3 mL in the same vial size give three different syringe readings for the same dose amount, and you will not be able to tell which one you used by looking.

If a vial's date is unknown, its water volume is unknown, or its storage history is unknown, this page cannot resolve that. There is no test you can run by eye. The information either was recorded at mixing or it was lost.

What we do not know

We hold no reliable human pharmacokinetic data for Tesamorelin, so this site makes no claims about its half life, how long it takes to clear, or how it accumulates. The arithmetic below concerns concentration and volume only.

This page answers arithmetic and handling questions. It does not tell you what dose to take, what to expect, or whether anything is appropriate for you, and there is no medical review behind it.

Common questions

Does the 28 days start when I first use the vial?

No. It starts on the day bacteriostatic water was added to the powder. First puncture of the stopper is not the trigger. A vial mixed and then left untouched in the fridge is still consuming its window.

What if my mixed vial sat out overnight?

The table shows a 2 day window at room temperature against 28 days refrigerated, which tells you the two conditions are not interchangeable. It does not tell you what to do with a specific vial that warmed up. That is a judgment call and this site has no medical review behind it.

Can I mix Tesamorelin with something other than bacteriostatic water?

The windows on this page are computed for bacteriostatic water specifically, because the preservative in it is what supports a multi-day multi-dose window. Diluents without a preservative are a different handling case and are not covered by these figures.

How long does Tesamorelin stay in your system?

We do not answer that. There is no reliable human pharmacokinetic data for Tesamorelin available to this site, so we make no claim about half life, clearance, or accumulation. The numbers here describe the vial, not the body.

Does using more water make the vial last longer?

No. The window is set by storage condition and diluent type, not by the water volume. A 10 mg vial in 3 mL and the same vial in 1 mL carry the same refrigerated window. Water volume changes concentration and syringe readings, nothing else here.

How long can I keep unmixed vials?

Dry powder held refrigerated is the stable form, listed as months to years. The practical limit is the date the vendor puts on it. Leaving spare vials unmixed is the only way to keep them out of the 28 day clock.