Peppy vs LynkDose: two private iPhone peptide trackers
LynkDose is a local-first iPhone peptide tracker that correlates doses with Apple Health sleep, HRV and glucose and adds an AI assistant on a 7-day trial then subscription, so pick it for biometrics and AI insights. Peppy is also iPhone-only and private, covers 123 compounds including 21 GLP-1s, has a body map, and its free tier never expires.
| Feature | Peppy | LynkDose |
|---|---|---|
| Platform | iPhone only (iOS 18+) | iPhone only (iOS 26+); also Mac and Vision |
| Compounds covered | 123 built in: 21 GLP-1s plus research peptides, custom allowed | BPC-157, TB-500, ipamorelin, CJC-1295, GHK-Cu, PT-141, epitalon, Selank, Semax and 25+ more, plus custom |
| Reconstitution calculator | Yes, free. Inline and standalone | Yes, to mL and syringe units; also free on the web |
| Medication level / half-life chart | Yes (Pro). 'Active in your system' curve for about 62 compounds | Not listed |
| Injection site rotation | Yes, free. 13-site body map, suggests the next site; heat-map (Pro) | Yes, full-body heatmap with auto-rotation |
| Reminders | Yes (Pro) | Yes, daily to custom frequencies |
| Vial / pen inventory | Yes (Pro). Doses left, runs-out date, running-low alert | Yes: unreconstituted, reconstituted and pre-mixed, with expiration alerts |
| Titration and cycles | Yes (Pro). Dose ladder auto-advances; on/off cycles | Yes, auto-titration and cycle tracking |
| Apple Health | Yes, free. Weight in and out | Reads weight, sleep, HRV, resting heart rate, glucose, steps, body fat, VO2 max; 30-day correlation |
| AI features | None | AI protocol assistant and chat grounded in your data |
| Price | Free tier; Pro $29.99/yr or $5.99/wk, 7-day trial | Free download with 7-day trial; App Store lists $2.99/wk, $4.99 and $6.99/mo, $24.99 and $39.99/yr |
| Account required | No. On-device plus your iCloud | Not stated; 'local-first' |
Compared against LynkDose's public website and App Store listing on 2026-08-30. If something changed, tell us and we will fix it.
Who each app is for
Peppy vs LynkDose is the rare comparison where both apps agree on the basics: iPhone only, local-first, built around the peptide workflow rather than bolted onto a habit tracker. LynkDose pitches itself to "serious biohackers" who want every dose linked to their biometrics. It reads sleep, HRV, resting heart rate, blood glucose, steps, body fat and VO2 max from Apple Health, charts 30-day trends against your doses, sends a weekly summary, and includes an AI protocol assistant and chat grounded in your own data. Its compound list leans research: BPC-157, TB-500, ipamorelin, CJC-1295, GHK-Cu, PT-141, epitalon, Selank, Semax and 25+ more.
Peppy is for the person who wants the shot handled and the weight trend visible without an AI in the loop. It covers the same research compounds plus 21 GLP-1 entries, so a Zepbound pen and a BPC-157 vial live in the same Today list, and its free tier does not expire.
Feature by feature
The table reflects each app's own site or App Store page as of 2026-08-30.
Apple Health depth. LynkDose wins. Peppy reads weight history and writes every weigh-in, and plots weight with goal and step-up markers (Pro). LynkDose pulls seven more metrics and correlates them. If you want to know whether a compound changed your sleep, that is LynkDose's whole thesis.
Site rotation. Both use a body heatmap. LynkDose tracks every site and auto-rotates to prevent overuse. Peppy's 13-site front and back map is free, marks the suggested site, shows "last used 6 days ago" and rotates across every protocol; the heat-map view is Pro. See injection site rotation.
Calculator, inventory, cycles, titration. Close to even. Both calculate units from vial, water and dose (Peppy's is free and inline in the editor). Both track inventory with expiration or running-low alerts, both auto-titrate, both handle cycles. In Peppy those three are Pro. Always verify with your prescriber.
Levels chart. Peppy only. Its "Active in your system" curve (Pro) is a half-life estimate for about 62 compounds. LynkDose does not list one. See how long semaglutide stays in your system.
GLP-1s. Peppy's catalog has 21 GLP-1 entries with pen and vial forms, and its check-in defaults to nausea, constipation, heartburn, sulfur burps and food noise. LynkDose publishes GLP-1 tracking guides and accepts custom compounds, but its listing does not name GLP-1s in the pre-loaded list.
AI. LynkDose only. Peppy has no AI features and no plans for a coach in 2.x.
Export. LynkDose exports progress photos and generates share cards on-device. Peppy's export (Pro) is a multipage PDF report or a CSV of doses and check-ins, built for handing to a prescriber rather than posting. See export your dose log for your doctor.
Pricing
LynkDose is free to download with a 7-day trial. Its site does not publish prices; the App Store listing shows $2.99 weekly, $4.99 and $6.99 monthly, $24.99 quarterly and $24.99 or $39.99 yearly options.
Peppy's free tier is one active protocol with logging, calendar, calculator, check-ins, site rotation, Apple Health and iCloud, with no time limit. Pro is $29.99 a year or $5.99 a week with a 7-day trial and adds reminders, insights charts, unlimited protocols, cycles and titration, inventory, photos, export and widgets.
Privacy and data
LynkDose says it is "privacy-first and local-first" and generates share cards on-device. Its App Store privacy label lists purchases and usage data as linked to you, and location and identifiers used for tracking across apps. Whether an account is required is not stated.
Peppy has no account, no server and no tracking of that kind. Data lives on your iPhone and in your own iCloud. Export (Pro) is a PDF or CSV you control. See private peptide tracker.
How to do this in Peppy
- Protocols tab, tap +, search your compound. Set dose, schedule, color and a cycle if you run one (cycles are Pro).
- Open the Calculator in the editor: vial mg, water mL, dose. Peppy shows "Draw up N units".
- Calendar: tap the days you already dosed and choose Add dose to carry your history across.
- Settings: turn on "Sync weight with Apple Health" to import your weight history.
- Log the next shot from Today: tap the site on the body map, adjust time or dose if needed, save.
Track it in Peppy
123 compounds built in, the units math done for you, body-map site rotation and reminders — private on your iPhone.
Free · iPhone · no accountFrequently asked
Is LynkDose free?
LynkDose is free to download with a 7-day free trial. Its App Store listing shows subscriptions from $2.99 a week to $39.99 a year. Peppy's free tier (one protocol, calculator, body map, calendar, check-ins, Apple Health) has no time limit; Pro is $29.99 a year.
Does LynkDose track GLP-1s like semaglutide?
LynkDose's site has guides for tracking semaglutide and tirzepatide and supports custom compounds, but its App Store listing highlights research peptides. Peppy ships 21 GLP-1 entries, from Ozempic and Zepbound to compounded and oral forms, with pen and vial handling built in.
Which app has a half-life chart?
Peppy. Its Progress tab shows an "Active in your system" curve estimated from each compound's half-life (Pro). LynkDose's site and listing do not mention one.
Does Peppy correlate doses with sleep or HRV like LynkDose?
No. Peppy reads and writes weight with Apple Health and charts it against dose step-ups. LynkDose reads sleep, HRV, resting heart rate, glucose and more. If biometrics matter, LynkDose is the better fit.
Is LynkDose private?
LynkDose describes itself as "privacy-first and local-first". Its App Store label lists purchases and usage data as linked to you and location and identifiers used for tracking. Peppy has no account and no server.
Not medical advice. Peppy is a tracking tool, not medical advice. Dose calculations are mathematical conversions only. Always follow your prescriber's instructions and verify every draw-up yourself.