--- title: "Peptide Library vs Peptide Tracker: Free Tracker or Research Platform?" canonical_url: https://peptidelibrary.app/compare/peptide-library-vs-peptide-tracker description: "Peptide Tracker is free with no subscription. See how it compares with Peptide Library on research, vendor prices, inventory, devices and pricing." updated: 2026-10-25 publisher: Peptide Library notice: "Research and educational use only. Not medical advice." --- # 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. ## Quick verdict 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. ### 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. ### 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. ## Key differences ### 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. ## Research 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. ## Tracking 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 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. ## Pricing 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. ## Where Peptide Tracker is stronger ### 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. ## Features | Feature | Peptide Library | Peptide Tracker | |---|---|---| | iPhone app | Yes | Yes | | Android app | Yes | Yes | | Web app | Yes, installable | Yes | | Free plan | Yes (inventory: 1 peptide) | Free, no subscription | | Dose logging | Yes | Yes | | History and calendar | Yes | Yes | | Recurring schedules | Yes | Yes | | Reminders | Yes | Yes | | Cycles and titration | Yes | Yes | | Vial inventory | Yes (free: 1 peptide) | Yes | | Low-stock or run-out alerts | Yes | Not advertised | | Expiry dates | Yes | Not advertised | | Stock deducted on logging | Yes | Yes | | Compound library | 200+ profiles | Yes (no count published) | | Cited research references | Yes | Not advertised | | Publication and trial data | Yes | Not advertised | | Community research trends | Yes (full view with Pro) | Not advertised | | Vendor directory | Yes | Not advertised | | Vendor price comparison | Yes | Not advertised | | Price per mg | Yes | Not advertised | | Vendor reviews | Yes | Not advertised | | Reconstitution calculator | Android and web | Free on the web; iPhone app unclear | | Estimated level charts | No | Yes | | Weight and body metrics | Yes | Yes | | Progress photos | Yes (free: up to 2) | Yes | | Journal or symptom check-ins | Yes | Yes | | Injection-site rotation | In the apps, not on the web | Yes | | Nutrition tracking | No | Manual entries | | Community | Discussions free; Q&A with Pro | Yes | | Apple Health | Yes | Yes | | Health Connect (Android) | Yes | Yes | | Wearables | No | Not advertised | | Home Screen widgets | iPhone only | Not advertised | | AI assistant | No | Yes | | Multi-device sync | Pro (free Android accounts sync most data) | Yes | | On-device storage | Yes | Not advertised | | Data export | Pro | On request | ## Final verdict 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. ## Frequently asked 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. Comparisons use public listings and websites. "Not advertised" means no source we checked mentions the feature, not that it is missing.