Short answer: A vial lasts until whichever comes first: it runs out, or it reaches its discard date after mixing or first use. Work out doses per vial (amount in the vial ÷ amount per dose), then check how many of those doses fit before the discard date. Count syringes, alcohol swabs and diluent too, since running out of supplies stops you just as surely. Then set an order-by date: the day you will run out, minus the time a refill takes to arrive, minus a few days of buffer. Discard dates come from the product label; FDA-approved examples range from 7 days (Egrifta WR) to 30 days (Novarel hCG) after mixing.
Running out mid-protocol is one of the most common, and most avoidable, problems people describe with peptides and hormone injections. It usually happens for one of three reasons: the vial gave fewer doses than expected, a vial had to be thrown out before it was empty, or something other than the drug ran out. This guide walks through the math and the habits that prevent all three. It does not give doses; the numbers below are examples.
The basic number is:
Doses per vial = amount in the vial ÷ amount per dose
Example: a 10 mg vial used at 0.5 mg per dose gives 10 ÷ 0.5 = 20 doses. The amount of water you add changes the concentration and the units you draw, but not the number of doses. For the units side, see how to read an insulin syringe.
In practice you usually get a little less than the math says. Some liquid stays in the vial where the needle cannot reach, and every air bubble you push out costs a bit of solution. Plan as if the last dose might not be there.
Once a powder is mixed, or a multi-dose vial is first punctured, a clock starts. For FDA-approved products, the label sets it. Some examples we checked:
| Product | Label limit after mixing or opening |
|---|---|
| Egrifta WR (tesamorelin) | Discard 7 days after mixing |
| Forzinity (elamipretide) | Discard vials 8 days after first opening |
| Novarel (hCG) | Refrigerate and use within 30 days of reconstitution |
| Bacteriostatic water supplied with Egrifta WR | Throw away what is left 28 days after first use |
Our storage guide lists more labels. For research peptides there is no tested figure at all, which is a reason to plan conservatively, not a reason to stretch.
Now combine the two numbers:
Usable doses = the smaller of (doses per vial) and (doses you will take before the discard date)
Example: 20 doses per vial, one dose a day, 30-day limit → all 20 doses fit; the vial lasts 20 days. Same vial, same limit, but one dose every three days → only about 10 doses fit in 30 days, and the rest is thrown away. If you see a lot of waste, the fix is a conversation with your prescriber or pharmacist about vial size, not keeping the vial past its date.
Days per vial = usable doses × days between doses
Then add up every vial you have, mixed and unmixed. Unmixed vials have their own expiry date, and mixing starts the shorter after-mixing clock, so keep them separate in your count and only mix a new vial when you need it.
The drug is only one part of what you need. For each injection you typically use:
And for each vial you mix, a measured amount of diluent (often bacteriostatic water) plus a mixing syringe. A 30 mL bottle of bacteriostatic water does not last for 30 mL of mixing if its label says to discard it 28 days after first use, as the Egrifta WR bottle does. Supplies often run out before the drug because nobody counts them. See bacteriostatic vs sterile water.
This is the step most people skip.
Order-by date = run-out date − refill lead time − buffer
Example: 18 days of supply left, refills take 7 days, 4 days of buffer → order within 7 days. Put that date on a calendar.
Dose Track tracks each vial's remaining volume and expiration date. When you log a reconstitution it sets an expiry warning (28 days by default, with a per-compound override you should set to your product's label), subtracts each logged dose from what is left, and notifies you when a vial is running low or close to expiring. The inventory screen also tracks supplies such as syringes and water, and shows an "order by" date based on how long your refills take to arrive, so the reminder comes before the run-out instead of after.
Questions about the app? See the help center or join the Dose Track community.
Every number in this article comes from one of these sources, checked on October 22, 2026. This article is for education. It is not medical or legal advice, and nothing here is a dose recommendation.