Category comparison
Spreadsheet versus app
Last reviewed · Written by the PepCycle team
A spreadsheet has two genuine advantages no app can match: complete data ownership and zero vendor risk. It has three genuine weaknesses: no reminders, arithmetic you can mistype, and no structured site data. Which matters more depends entirely on how many compounds you run and how disciplined you are.
The honest comparison
| Spreadsheet | Tracking app | |
|---|---|---|
| Data ownership | Complete — it is your file | Depends entirely on export quality |
| Vendor risk | None | The app can be discontinued or change |
| Reminders | None | Yes, scheduled and repeating |
| Arithmetic | Manual, or formulas you maintain | Automatic, and consistent |
| Site tracking | Free text at best | Structured, often visual |
| Vial countdown | You maintain it | Automatic |
| Speed of an entry | Slow on a phone | A few taps |
| Cost | Free | Usually a subscription |
| Survives 5 years? | Yes, if you keep the file | Only if export works |
Where the spreadsheet genuinely wins
- You own the file outright. No subscription, no account, no company that can pivot away from your use case.
- Total flexibility. Any protocol shape, any column you invent, no data model fighting you.
- It will open in twenty years. CSV is about as future-proof as a format gets.
- Analysis is trivial. Pivot tables and charts on your own data, with no export step.
These are not small advantages, and anyone dismissing spreadsheets outright is not being straight with you. If you are running one compound on a simple schedule and you are naturally organised, a spreadsheet is a completely reasonable choice.
Where the spreadsheet genuinely loses
- Reminders. A spreadsheet cannot notify you, and a separate calendar reminder decoupled from the log drifts out of sync within weeks.
- Arithmetic. The reconstitution conversion is easy to get right once and easy to mistype at 7am. A formula helps until someone overwrites a cell.
- Structured sites. Free-text site entry means rotation can never be summarised or mapped — see injection site rotation.
- Entry friction on a phone. Every second of friction reduces the chance the entry happens at all, and an incomplete log is worse than none.
- Vial countdown. Manually maintaining remaining contents across backdated entries is exactly the kind of bookkeeping people stop doing in month two.
If you choose the spreadsheet, build it like this
Two sheets, not one. A vials sheet and an entries sheet, joined by a vial ID — the same structure any decent app uses internally.
Sheet 1 — Vials
vial_id·compound·form(lyophilised / pen / solution)mass_mg·diluent_ml·concentration_mcg_per_ml(a formula, not typed)lot·supplier·received_date·reconstituted_date·discard_date
Sheet 2 — Entries
datetime(actual, not scheduled) ·vial_id·amount_mcg·volume_ml·unitsroute·site(from a fixed dropdown, never free text)status(taken / skipped / late) ·notes
Use data validation for site and status, and derive volume_ml and units with formulas from the vial's concentration rather than typing them. That single discipline is the difference between a log and a pile of numbers.
You can do both
The strongest position is not either/or. Use an app for daily entry, reminders and arithmetic, and export to CSV periodically so you hold the file yourself. You get the friction-free entry and the ownership.
That only works if the export is complete. An export missing vial concentrations recreates the exact spreadsheet failure described above. See exporting your log for what a real export contains — and PepCycle's exports include vials, concentrations and blend components, not just entries.
Frequently asked questions
Is a spreadsheet good enough for tracking peptides?
For a single compound on a simple schedule, and someone naturally organised, genuinely yes. It offers complete data ownership and no vendor risk. What it cannot do is remind you, calculate reliably, or record sites in a way that can be summarised.
What is the most common mistake in a spreadsheet peptide log?
Omitting the vial concentration. Rows of dates and syringe-unit readings without the concentration they came from cannot be converted into amounts by anyone, which makes the whole sheet uninterpretable after the fact.
Can I use both a spreadsheet and an app?
Yes, and it is arguably the strongest setup: use the app for entry, reminders and arithmetic, then export to CSV periodically so you hold your own file. This only works if the export includes vial concentrations rather than just entries.
How should I structure a spreadsheet log?
Two sheets joined by a vial ID: one for vials (mass, diluent volume, derived concentration, dates, lot) and one for entries (actual datetime, vial ID, amount, route, site, status). Use dropdowns for site and status, and formulas rather than typed values for anything derived.
Related pages
Run the tests on us too
Download PepCycle and try the awkward cases yourself: a 200 mg vial, a three-peptide blend, an every-3-day schedule, and an entry backdated eleven days. That is a better evaluation than any comparison page, including this one.
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