Doses, days and vials

Vial Supply Calculator

Enter the vial size, dose and how often you dose. See how long one vial lasts and how many vials a plan of a given length needs.

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Vial supply calculator

Example values are loaded. Replace them with the numbers on your own vial.

mg
per week
weeks
days

28 days is the common limit for multi-dose vials after first puncture. Your pharmacy label wins.

U-100 syringe: 100 units = 1 mLHow this is tested

The math

Doses per vial = vial (mg) ÷ dose (mg), rounded down
Days per vial = doses per vial ÷ doses per week × 7
Vials needed = total doses ÷ doses per vial, rounded up

Doses per vial is rounded down because a partial dose left in a vial is not a full dose. Vials needed is rounded up for the same reason: this calculator assumes you do not combine leftovers from two vials.

The 28-day question

A vial that has been punctured has a limited time it can be used, called the beyond-use date. For multi-dose vials, the common default in US pharmacy standards is 28 days after first puncture unless the manufacturer says otherwise. Your pharmacy label or product insert is the authority. The calculator lets you set the window and warns you if one vial lasts longer than it.

Frequently asked questions

How many doses are in a 10 mg vial?

Divide 10 by your dose in mg and round down. At 2.5 mg per dose that is 4 doses; at 0.25 mg (250 mcg) it is 40 doses.

How long is a mixed peptide vial good for?

It depends on the product, the diluent and storage. Many multi-dose vials carry a 28-day use limit after first puncture. Follow your pharmacy label or product insert.

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