Peptide Inventory Math Nobody Does
Until they run out mid-cycle
6 min readYou ordered enough for “a few months.” Except one compound ran out in 10 days. Another expires before you finish it. And the third is backordered with a 2-week wait. Your protocol now has unplanned gaps because you didn't do the math upfront.
The Three Inventory Problems
1. Depletion Rates Diverge
Each compound in your stack runs out at a different rate. A typical 3-compound stack:
| Compound | Vial | Dose | Freq | Days/Vial | Reorder |
|---|---|---|---|---|---|
| BPC-157 | 5mg | 250mcg | 2x/day | 10 | Every 10 days |
| CJC-1295 | 2mg | 100mcg | 1x/day (5/2) | 28 | Monthly |
| Semaglutide | 5mg | 0.5mg | 1x/week | 70 | Every 10 weeks |
Three different reorder cycles that never synchronize. You can't just “order everything together monthly.”
Titer does this math automatically.
Tracks doses remaining, forecasts depletion, alerts before you run out.
2. Expiration Overlaps with Depletion
Reconstituted BPC-157 is stable for ~28 days. At 250mcg 2x/day, one vial lasts 10 days. That works. But what about CJC-1295?
Active days per week: 5
Doses per vial: 20
Days to deplete: 20 active days = 28 calendar days
Stability window: ~14 days reconstituted
Problem: Vial expires on day 14 but lasts 28 days of use.
You'll use half a CJC vial before it degrades. Either reconstitute smaller amounts (if available in smaller vials) or accept 50% waste.
3. Shipping Lead Times Create Gaps
Most peptide vendors ship in 3-7 business days. Some require 2+ weeks for international. If you order when a vial runs out, you have a gap. The reorder trigger should be:
BPC-157: 7 days lead x 0.5mg/day = 3.5mg buffer needed
Translation: Order new BPC when current vial has 7 days (3.5mg) remaining
The Full Inventory Calculation
For each compound in your stack, you need:
- Consumption rate - Dose x frequency = mg consumed per day
- Vial duration - Vial size / daily consumption = days per vial
- Expiration constraint - min(vial duration, stability window) = usable days per vial
- Effective yield - Usable days x daily consumption = mg actually used per vial
- Waste rate - (Vial size - effective yield) / vial size = % wasted
- Reorder trigger - Shipping days x daily consumption = mg remaining when you should order
- Cycle requirements - Protocol length / usable days per vial = vials needed for full cycle
Real Example: 8-Week BPC + CJC + Sema Stack
| Metric | BPC-157 | CJC-1295 | Semaglutide |
|---|---|---|---|
| Daily consumption | 0.5mg | 0.071mg (5/2) | 0.071mg |
| Vial size | 5mg | 2mg | 5mg |
| Days per vial | 10 | 28 | 70 |
| Stability limit | 28 days | 14 days | 56 days |
| Usable days | 10 (depletion) | 14 (expiration) | 56 (expiration) |
| Waste per vial | 0% | 50% | 20% |
| Vials for 8 weeks | 6 | 4 | 1 |
| Reorder trigger | 3.5mg remaining | Day 7 of vial | Week 7 |
Total upfront order: 6 BPC + 4 CJC + 1 Semaglutide vials. But you can't reconstitute them all at once (expiration). You need to sequence reconstitution: BPC every 10 days, CJC every 14 days, Semaglutide once at the start.
Why Nobody Does This
- It's tedious - Running these calculations for each compound, then tracking the dynamic state as you inject, is spreadsheet work that nobody maintains
- It changes with titration - Move from 0.25mg to 0.5mg semaglutide and every vial-duration calculation needs updating
- The consequences seem minor - A 3-day gap feels recoverable. But gaps compound across protocols, especially synergistic stacks.
Related
Titer does this math automatically.
Tracks doses remaining, forecasts depletion, alerts before you run out. Per compound.
See Plans & PricingDisclaimer: Educational content, not medical advice. Consult a healthcare provider for protocol guidance.