Peptide LibraryApp comparison • 2026
Peptide Library vs Peptide Tracker: Free Tracker or Research Platform?
A side-by-side look at tracking, inventory, research tools, vendor pricing and platforms, so you can pick the app that matches how you work.
Last verified · Published by Peptide Library, which has a commercial interest in this comparison. How we compare
Peptide Library
By Superfime LLC
A peptide research platform: cited research profiles, vendor and price comparison, tracking and inventory on iPhone, Android and the web.
Peptide Tracker
By Flat Six Labs (peptidetracker.ai)
A free peptide and GLP-1 tracker with vial inventory, estimated level curves, progress photos and a community Q&A, on iPhone, Android and the web.
Quick verdict
Peptide Library or Peptide Tracker?
Peptide Tracker, from Flat Six Labs, is a capable tracker that is free throughout: apps for iPhone and Android, a web app, inventory, progress photos and a community Q&A, with no subscription. Peptide Library tracks too, but it is built around research and buying decisions, with cited peptide profiles, publication and trial data, and vendor price comparison in the same account. If a free log is all you need, Peptide Tracker is hard to argue with. If you also research compounds and compare vendors, Peptide Library keeps that work next to your tracker.
Peptide Library
Choose Peptide Library if…
- You want 200+ cited research profiles, with PubMed and ClinicalTrials.gov references, next to your tracker.
- You compare vendors before buying: listings, price per mg within the same product form, coupon codes and vendor reviews.
- You want publication and clinical-trial statistics from the Research Intelligence Center.
- You want inventory that plans ahead, with run-out and reorder-by dates and low-stock, reorder and expiry alerts.
Peptide Tracker
Choose Peptide Tracker if…
- You want every tracking feature free, with no subscription at all.
- You want estimated level curves drawn from your logged doses.
- You want an active Q&A community and an AI assistant in the app.
At a glance
Feature comparison: Peptide Library vs Peptide Tracker
Every cell comes from a cited source; numbers link to the source list at the end of the page. "Not advertised" means no source we checked mentions the feature, not that the app lacks it.
- Verified
- Verified, with limits
- Verified absent or removed
- Not advertised by the developer
- Not verified (sources disagree or unclear)
Research4 features
| Feature |  Peptide Library |  Peptide Tracker |
|---|---|---|
| Compound library | 200+ profiles7 | |
| Cited research references | Yes7 PubMed, ClinicalTrials.gov, DailyMed and EMA references on profiles. | Not advertised |
| Publication and trial data | Yes8 Research Intelligence Center: publication and trial statistics. | Not advertised |
| Community research trends | Not advertised |
Vendor discovery4 features
| Feature | Peptide Library | Peptide Tracker |
|---|---|---|
| Vendor directory | Yes10 | Not advertised |
| Vendor price comparison | Yes11 | Not advertised |
| Price per mg | Not advertised | |
| Vendor reviews | Yes10 | Not advertised |
Availability4 features
| Feature | Peptide Library | Peptide Tracker |
|---|---|---|
| iPhone app | Yes3 | Yes14 |
| Android app | Yes4 | |
| Web app | Yes, installable5 Library, calculators and vendor prices need no account; tracking needs a free account. | Yes15 The web app signs in to the same account as the phone apps. |
| Free plan | Yes (inventory: 1 peptide)1 |
Inventory4 features
| Feature | Peptide Library | Peptide Tracker |
|---|---|---|
| Vial inventory | Yes (free: 1 peptide)1 | Yes14 Mixed and unmixed vials, blends, BAC water and supplies. |
| Low-stock or run-out alerts | Yes4 Run-out and reorder dates with stock alerts. | Not advertised |
| Expiry dates | Yes4 | Not advertised |
| Stock deducted on logging | Yes4 |
Tracking2 features
| Feature | Peptide Library | Peptide Tracker |
|---|---|---|
| Dose logging | Yes14 | |
| History and calendar | Yes4 | Yes14 |
Scheduling3 features
| Feature | Peptide Library | Peptide Tracker |
|---|---|---|
| Recurring schedules | Yes1 | Yes14 |
| Reminders | Yes14 | |
| Cycles and titration | Yes4 On/off cycles, every-N-days, several times a day and titration. | Yes15 Interval, on/off and titration schedules. |
Calculations2 features, 1 not verified
| Feature | Peptide Library | Peptide Tracker |
|---|---|---|
| Reconstitution calculator | ||
| Estimated level charts | No1 Profiles list half-lives; there is no modelled level chart. | Yes14 Estimated plasma-level curves from logged doses and half-life. |
Metrics and progress4 features
| Feature | Peptide Library | Peptide Tracker |
|---|---|---|
| Weight and body metrics | Yes1 | Yes14 |
| Progress photos | Yes (free: up to 2)1 | Yes14 Alignment guides and side-by-side compare. |
| Journal or symptom check-ins | Yes1 Journal check-ins with mood, energy, sleep and symptoms. | |
| Injection-site rotation | In the apps, not on the web4 | Yes14 |
Nutrition and wellness1 feature
| Feature | Peptide Library | Peptide Tracker |
|---|---|---|
| Nutrition tracking | No1 | Manual entries15 |
Community1 feature
| Feature | Peptide Library | Peptide Tracker |
|---|---|---|
| Community | Yes14 Connect: questions and structured answers under usernames. |
Integrations4 features
| Feature | Peptide Library | Peptide Tracker |
|---|---|---|
| Apple Health | Yes6 Reads weight and body fat; never writes. | Yes15 |
| Health Connect (Android) | Yes6 Reads weight and body fat; never writes. | Yes15 |
| Wearables | No1 No Oura, WHOOP or Apple Watch app. | Not advertised |
| Home Screen widgets | iPhone only4 Home Screen and Lock Screen widgets ship in the iPhone app; Android has none yet. | Not advertised |
AI1 feature
| Feature | Peptide Library | Peptide Tracker |
|---|---|---|
| AI assistant | No1 No AI in the app. A public, read-only MCP server lets AI assistants look up library profiles. |
Data, sync and privacy3 features
| Feature | Peptide Library | Peptide Tracker |
|---|---|---|
| Multi-device sync | Pro (free Android accounts sync most data)1 | Yes15 One account across iPhone, Android and the web. |
| On-device storage | Not advertised Data is tied to the account; the site does not say where it is stored. | |
| Data export | Pro1 | On request14 |
Want research, vendor prices and tracking in one place? Peptide Library has a free plan.
The difference
What makes Peptide Library different?
Research depth, not only a compound list
Peptide Tracker has a library of common compounds and lets you add your own; the developer does not publish a count. Peptide Library profiles state mechanism, half-life and regulatory status and cite their sources, and the Research Intelligence Center adds publication and trial counts per peptide.
Vendor and price research
Peptide Tracker's listing and website don't mention vendors or prices. Peptide Library's Shop compares vendor listings and price per mg, shows coupon codes, and lists vendors that ship to your country first.
Inventory that looks ahead
Both apps take stock off a vial when you log. Peptide Library also estimates doses left, run-out and reorder-by dates, and alerts on low stock and expiry across vials, capsules and nasal sprays.
Two different ideas of free
Peptide Tracker is free throughout and funded by optional Founding Member purchases. Peptide Library's free plan covers the library, vendor prices, logging, schedules, journal and metrics; more than one peptide in inventory, sync on iPhone, export and the Community Q&A need Pro.
These pieces work together: read a profile, compare vendors on price per mg, add what you bought to inventory, and every logged dose updates your stock, calendar and journal.
Research
Research library: a reference platform or a tracking companion?
A tracking-first app answers "what did I take, and when?". A research platform also answers "what is this compound, how strong is the evidence, and who is studying it?". Peptide Tracker leans toward the first: its compound entries cover basics such as half-life, routes, side effects and storage, and it adds free courses and a Peptide Assistant for general questions.
Peptide Library's 200+ research profiles cite PubMed, ClinicalTrials.gov, DailyMed and EMA sources and label studies by evidence type. The Research Intelligence Center publishes publication and clinical-trial statistics with its methodology, and Peptide Trends shows which peptides the community is researching, as percentages only.
Browse the 200+ research profiles · See the Research Intelligence Center
Tracking
Tracking, scheduling and inventory workflows
Both apps follow the same loop: add a compound, build a schedule, get a reminder, log the dose and review your history on a calendar. Peptide Tracker supports interval, on/off and titration schedules, a weekly checklist and taken, skipped and missed status. Peptide Library supports every day, chosen weekdays, every N days, on/off cycles, several times a day and titration, and its calendar shows taken, missed and skipped doses by month or week.
Inventory is where the workflows part. Peptide Tracker tracks mixed and unmixed vials, blends and bacteriostatic water, and updates stock when you correct a dose or change its vial. Peptide Library also deducts stock when you log, then forecasts doses left, run-out and reorder-by dates, and keeps price, dates, vendor and COA for each container.
Peptide Tracker draws an estimated plasma-level curve from your logs and each compound's half-life. Peptide Library lists half-lives on its profiles but does not model levels.
Vendors
Vendor and pricing research
Peptide Tracker concentrates on your own records and does not advertise vendor listings or price comparison. If you already know where you buy, that may be all you need. If you compare sources, Peptide Library's Shop groups offers by compound and product form, shows price per mg after any coupon code, and links to vendor profiles with reviews and the shipping details a source supports.
Compare listings
Offers grouped by compound and product form, never mixed across forms.
Price per mg
Unit prices after any vendor coupon code, from what the listing shows.
Vendor profiles
Reviews, coupons and the shipping details a source supports.
About vendor listings. Vendor listings, prices, reviews, coupon codes and commercial partnerships are not independent proof of a product's purity, safety, legitimacy or suitability for human use, and a listing is not an endorsement. Peptide Library does not sell peptides. Some vendor links are affiliate links; affiliate status never changes the order vendors appear in.
Screens
Inside Peptide Library
Screens from Peptide Library on the web and in the app. We don't show Peptide Tracker's screens; see its store listing for those.
Body metrics with trends, next to your logs. 
A calendar of what was logged and what is next. 
Inventory with uses left, run-out dates and reorder alerts. 
Schedules, reminders and a daily log with streaks.
Pricing
Pricing: Peptide Library vs Peptide Tracker
Peptide Tracker's listing and website both say there is no subscription and no paywall; Founding Member purchases on the App Store are optional support. Peptide Library has a free plan and a Pro plan at $4.99 a month, $39.99 a year or $89.99 once. The main free-plan limits are one peptide in inventory and two progress photos.
| Plan | Peptide Library | Peptide Tracker |
|---|---|---|
| Free access | Free1 Library, vendor prices, logging, schedules, journal and metrics are free. Inventory is limited to 1 peptide. | Free1415 The listing and site say there is no subscription and no paywall. |
| Monthly | $4.9921 | Not listed |
| Annual | $39.9921 | Optional $20–$801415 Founding Member purchases support development; the site says tracking does not require one. |
| Lifetime | $89.9921 | Not listed |
| Model | Free plan; Pro subscription or lifetime purchase | Free, with no subscription; optional Founding Member purchases and tips |
- US prices, checked October 25, 2026. Store prices vary by country and change; the price shown in each app before purchase is the one that applies. Check official pricing before you subscribe.
- Peptide Library: US prices. App Store and Google Play prices are set per country and shown in the app before purchase.
Fair is fair
Where Peptide Tracker wins
Everything is free
The developer states there is no subscription or paywall. Logging, schedules, inventory and photos are all included without paying.
Estimated level curves
A modelled curve per compound from your logged doses and its half-life. Peptide Library does not offer this.
A community built around answers
Its Connect Q&A uses structured answers, quotes and mentions under usernames. Peptide Library's discussions are public, but its Q&A is part of Pro.
An AI assistant
Peptide Assistant answers general questions in the app. Peptide Library has no in-app AI.
Who it suits
Who should use which app?
You want a free tracker and nothing more
Peptide Tracker
No subscription, and logging, schedules, inventory and photos are included.
You read the research before you start
Peptide Library
Cited profiles, evidence labels and research statistics sit next to the tracker.
You compare vendors and prices
Peptide Library
Price per mg by product form, coupon codes and vendor reviews.
You want level curves and a Q&A community
Peptide Tracker
Both are built in and free.
You move between phone and browser
Either
Both offer a web app that signs in to the same account as the phone apps.
Final verdict
The verdict on Peptide Library vs Peptide Tracker
Peptide Tracker is a generous, well-rounded free tracker, and for many people it will be enough. Peptide Library is the better fit when tracking is one part of a process that also includes reading the evidence and comparing vendors before you buy.
You don't have to decide blind: Peptide Library's library, research pages and vendor prices are free to browse on the web without an account.
Get the Peptide Library app, or start on the web without an account.
FAQ
Peptide Tracker vs Peptide Library: common questions
Is Peptide Tracker really free?
Its App Store listing and website say there is no subscription and no paywall. Optional Founding Member purchases ($20 to $80 on the App Store) and tips support development. Checked October 2026.
Does Peptide Tracker compare vendor prices?
Its listing and website don't mention vendors or prices. Peptide Library's Shop compares vendor listings and price per mg within each product form, with coupon codes and vendor reviews.
Which app has the bigger research library?
Peptide Tracker doesn't publish a count, so we can't compare sizes directly. Peptide Library has 200+ research profiles, each citing PubMed, ClinicalTrials.gov, DailyMed or EMA sources.
Do both apps work on Android and in a browser?
Yes. Peptide Tracker and Peptide Library both have Android apps and web apps that use the same account as the phone apps. Peptide Library's web app can also be installed from the browser.
Does Peptide Library show estimated level curves?
No. Peptide Library's profiles list half-lives, but it doesn't model levels from your logs the way Peptide Tracker does.
Can I move my records from Peptide Tracker to Peptide Library?
There's no direct import between the two apps. Peptide Tracker exports data on request; in Peptide Library you would add your current schedules and inventory, then log from there.
Explore More Than Peptide Tracking
Research peptides, organize your tracking, manage inventory, and compare vendors in one place.
Free plan available. Pro adds unlimited inventory, sync on every device, export and more; see Free vs Pro.
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See all peptide tracker comparisonsHow the Peptide Library tracking app works
Peptide Library
By Superfime LLC
Peptide Tracker
By Flat Six Labs (peptidetracker.ai)
Peptide Tracker Log & Reminder is developed by Flat Six Labs LLC (peptidetracker.ai).
Sources
Store listings and developer websites as read on the date shown. Competitor details can change after that date.
- 1.Peptide Library Free vs Pro (Peptide Library, read )
- 2.Peptide Library pricing (Peptide Library, read )
- 3.Peptide Library and Tracker on the App Store (Apple App Store, read )
- 4.Peptide Library and Tracker on Google Play (Google Play, read )
- 5.Install the Peptide Library web app (Peptide Library, read )
- 6.Peptide Library privacy policy (Peptide Library, read )
- 7.Peptide Library research profiles (Peptide Library, read )
- 8.Research Intelligence Center (Peptide Library, read )
- 9.Peptide Trends (Peptide Library, read )
- 10.Peptide vendor directory (Peptide Library, read )
- 11.Compare peptide prices and vendors (Peptide Library, read )
- 12.Peptide calculator (Peptide Library, read )
- 13.Peptide Library community discussions (Peptide Library, read )
- 14.Peptide Tracker Log & Reminder on the App Store (Apple App Store, read )
- 15.peptidetracker.ai (Flat Six Labs, read )
- 16.Peptide Tracker on Google Play (Google Play, read )
Disclosure and method
Peptide Library publishes this comparison and has a commercial interest in helping you evaluate its platform. Competitor features and pricing are reviewed using publicly available information: App Store and Google Play listings and each developer's own website, read on . We identify situations where another app may be a better fit.
We did not install or test competitor apps for these pages, and we don't score or rank them. A feature no source mentions is shown as "Not advertised", never as missing. App names and icons are trademarks of their respective owners, used only to identify the apps; Peptide Library is not affiliated with or endorsed by them.
Spotted something out of date? Tell us and we'll check it against the developer's sources. Corrections follow our editorial policy.
Research and educational use only. Not medical advice. Peptide Library does not sell peptides.