How Long Does a Peptide Vial Last? Doses and Days

The duration a peptide vial lasts is determined by two factors, and whichever limit is reached first wins. The first factor is the number of doses it contains, which is calculated by dividing the vial's mg by your specific dose. The second factor is the duration for which the vial remains usable once mixed, as guided by the peptide's storage instructions.

A 10 mg vial offers 40 doses at 250 mcg. If administered daily, this equates to 40 days of doses. However, if the mixed vial's usability extends only 4 weeks, this time frame is the limiting factor.

doses = vial mg × 1,000 ÷ dose mcg

To calculate doses, convert the vial's mg to mcg by multiplying by 1,000, then divide by your dose in mcg. A 10 mg vial contains 10,000 mcg. With a dose of 500 mcg per administration, it holds 20 doses. When the dose is provided in mg, it must also be converted: 2.5 mg becomes 2,500 mcg, yielding 4 doses from the same vial. For vials labeled in IU, simply divide IU by IU without conversion.

The volume of water used is not part of this calculation. Increasing BAC water volume reduces concentration and alters the volume drawn, but the total peptide content remains constant. The peptide calculator provides doses per vial alongside the draw for any vial size, water volume, and dose entered.

The table calculates for a 10 mg vial at varying doses and schedules. A 10 mg vial is one of the calculator's preset sizes, which makes it a fair test. "5 per week" means five dosing days followed by two non-dosing days. Many of the extended calculations exceed the second limit, which is the usable window once the vial is mixed.

Worked examples, not dose recommendations.

Once BAC water is introduced, a distinct time frame starts. Each peptide's storage and stability section specifies its own duration of usability, and these durations vary.

For instance, the storage section on the BPC-157 page advises refrigeration at 2-8°C and usage within 3-4 weeks. The tirzepatide page recommends use within 4 weeks, while the semaglutide page advises within 6 weeks. The HCG page specifies a 60-day window, per the Pregnyl label.

There is a general standard as well. USP <797> is the US pharmacy standard for sterile compounding. It states that a manufactured multiple-dose vial should not be used beyond 28 days after its first puncture unless the manufacturer's label indicates otherwise. The CDC injection safety guidance echoes this 28-day rule. This label exception allows for HCG's 60-day window, derived from the Pregnyl label, to extend further.

Most research peptides that are self-mixed lack a manufacturer label for the mixed solution. Thus, the window varies by peptide, and no single duration is applicable to all vials. The peptide storage guide outlines handling guidelines, including refrigeration, light exposure, and signs of spoilage.

When doses are small and infrequent, the storage limit is reached well before the number of doses is depleted. At 250 mcg once weekly, a 10 mg vial contains 40 weeks of doses. If the peptide's storage section advises use within 4 weeks, only about 4 of those 40 doses fall within the viable period.

The remaining 36 doses, equating to 9 mg of peptide, remain in the vial when the viable period ends. The quantity remains unchanged, and the window does not expand. This surplus is the consequence of mixing a full vial for an infrequent, small dose.

Larger or daily doses alter the scenario. At 500 mcg daily, the vial is consumed in 20 days, comfortably within a 4-week window. Here, the dose count is the determining factor, with the window irrelevant.

A 10 mL measurement represents volume, not peptide quantity, so it cannot independently determine duration. The mg content is required. If concentration is provided on the label, multiply: 10 mL at 1 mg/mL is 10 mg, which holds 40 doses at 250 mcg or 20 at 500 mcg.

If the 10 mL vial contains BAC water, it contains no peptide. At 2 mL per mix, it supports five mixes. Each opened BAC water vial has its own post-opening window, so check its label for specifics.

Two dates are essential for every vial: the day it is mixed and the expiration of its usability window. Record both on the label when water is added.

The inventory tracker tracks remaining doses based on logged administrations, estimates when the vial will be depleted, and includes a use-by note you enter. Doses logged in the protocol planner decrement the count. A free account is required for this feature. The calculators do not need one.

Prior to mixing, consult how much BAC water to add and perform calculations using the BPC-157 calculator or tirzepatide calculator.