Running out of peptide mid-protocol is one of the most common and most preventable problems in peptide research. A gap of even a few days can break the consistency that makes multi-week protocols effective. The solution is straightforward supply planning — knowing exactly how long each vial lasts at your dose and having your next supply ordered before the current one runs out.
How to Calculate How Long a Vial Lasts
Every vial has a fixed total amount of peptide. How long it lasts depends on two variables: your dose per injection and how many times per day you inject.
The formula is simple:
Example: BPC-157
- Vial size: 5mg (5,000 mcg)
- Dose: 250 mcg per injection
- Frequency: 2x daily (500 mcg/day)
- Days per vial: 5,000 ÷ 500 = 10 days
Example: Semaglutide
- Vial size: 5mg
- Dose: 0.5mg per week (titration phase)
- Frequency: 1x weekly
- Weeks per vial: 5 ÷ 0.5 = 10 weeks
Use the dosage calculator to confirm your per-dose amount and the reconstitution calculator to verify your concentration before planning supply.
Vial Duration for Common Peptides
This table shows how long a single vial lasts at typical dosing protocols:
BPC-157 (5mg vial)
| Protocol | Daily Use | Days per Vial | Vials for 4 Weeks | Vials for 8 Weeks |
|---|---|---|---|---|
| 250 mcg 1x/day | 250 mcg | 20 days | 2 | 3 |
| 250 mcg 2x/day | 500 mcg | 10 days | 3 | 6 |
| 500 mcg 1x/day | 500 mcg | 10 days | 3 | 6 |
| 500 mcg 2x/day | 1,000 mcg | 5 days | 6 | 12 |
Semaglutide (5mg vial)
| Titration Phase | Weekly Dose | Weeks per Vial | Notes |
|---|---|---|---|
| 0.25 mg/week | 0.25 mg | 20 weeks | One vial covers the entire 0.25 phase plus more |
| 0.5 mg/week | 0.5 mg | 10 weeks | One vial covers this phase |
| 1.0 mg/week | 1.0 mg | 5 weeks | One vial covers this phase |
| 2.4 mg/week | 2.4 mg | ~2 weeks | Higher consumption — plan ahead |
Ipamorelin (5mg vial)
| Protocol | Daily Use | Days per Vial | Vials for 8 Weeks | Vials for 12 Weeks |
|---|---|---|---|---|
| 200 mcg 1x/day | 200 mcg | 25 days | 3 | 4 |
| 200 mcg 2x/day | 400 mcg | 12.5 days | 5 | 7 |
| 300 mcg 2x/day | 600 mcg | ~8 days | 7 | 11 |
Shelf Life: Reconstituted vs. Lyophilized
Supply planning is not just about quantity — timing matters too, because peptide shelf life depends on whether the vial has been reconstituted:
| State | Storage | Shelf Life | Notes |
|---|---|---|---|
| Lyophilized (powder) | Freezer (-20°C) | 2+ years | Best for bulk supply storage |
| Lyophilized (powder) | Refrigerator (2-8°C) | 6-12 months | Good for near-term supply |
| Reconstituted (bac water) | Refrigerator (2-8°C) | 3-4 weeks | Use within this window |
| Reconstituted (sterile water) | Refrigerator (2-8°C) | 24-48 hours | Single-session use only |
The key takeaway: buy your full supply up front as lyophilized powder (it stores for months), but only reconstitute one vial at a time. A vial that lasts 25 days at your dose is fine — it fits well within the 3-4 week reconstituted window. A vial that lasts 40 days at your dose may expire before you finish it, so consider adding less water to increase concentration and reduce the number of days per vial, or split the powder across two reconstitutions if your supplier offers smaller sizes.
Signs You Need to Reorder
Do not wait until you draw the last dose to think about your next vial. Here are the signals to start your reorder process:
- Less than 1 week of doses remaining. If your vial has 5 or fewer doses left and you inject daily, it is time to reconstitute a new vial or order more supply
- Approaching the 3-week mark on a reconstituted vial. Even if doses remain, a vial reconstituted more than 3 weeks ago is nearing the end of its reliable potency window
- Moving to a higher dose in a titration. Semaglutide users often forget that increasing the dose means the vial depletes faster. Recalculate your supply timeline each time you titrate up
- Entering the last vial of a multi-vial protocol. If your 8-week protocol requires 6 vials and you are opening vial #6, confirm that you have either enough to finish or more on order
How the Daily Tracker Handles Reorder Alerts
The DosageTools Daily Dose Tracker calculates your remaining supply based on your logged doses and vial information. Here is how it works:
- You enter your vial details — peptide amount, water volume, and reconstitution date. The reconstitution calculator can help you set these values
- Each logged dose subtracts from the vial total. The tracker knows exactly how much peptide remains
- Estimated depletion date is calculated based on your dosing frequency. If you inject 250 mcg twice daily and have 2,500 mcg left, the tracker knows you have 5 days of supply
- You see a clear alert when supply drops below your reorder threshold, giving you time to act before a gap occurs
This is especially valuable when running multiple compounds simultaneously. Tracking which vial runs out first across two or three peptides is difficult to do mentally — the tracker handles it automatically.
Planning for Multi-Week Protocols
Before starting any protocol, calculate your total supply needs for the full duration. This prevents the most stressful scenario: running out mid-cycle with no backup.
- Determine your total daily usage — dose per injection multiplied by injections per day
- Multiply by the total number of days in your protocol (e.g., 4 weeks = 28 days, 8 weeks = 56 days)
- Divide by your vial size to get the number of vials needed, then round up
- Add one extra vial as a buffer for waste, spills, or reconstitution errors
Pair the tracker with the dosage calculator to verify your per-dose syringe units and the reconstitution calculator to plan your water volumes. Together, these tools give you full visibility into your protocol supply from day one through the last injection.