--- title: "Peptide Library vs Pep AI: GLP-1 Wellness Tracking or Peptide Research?" canonical_url: https://peptidelibrary.app/compare/peptide-library-vs-pep-ai description: "Pep AI focuses on GLP-1 nutrition, symptoms and AI. Compare it with Peptide Library for peptide research, tracking, inventory and pricing." updated: 2026-10-25 publisher: Peptide Library notice: "Research and educational use only. Not medical advice." --- # Peptide Library vs Pep AI: GLP-1 Wellness Tracking or Peptide Research? Nutrition, symptoms and AI on one side; research, vendor pricing and inventory on the other. Here is how they line up. ## Quick verdict Pep AI is built around a GLP-1 routine: shots, food and protein, side effects, sleep and mood, with an AI companion called Arlo, an Apple Watch app and PDF reports. If that's your day-to-day, it's likely the better fit. Peptide Library is built for peptide research, with cited profiles, publication data and vendor price comparison, plus tracking and inventory, and its free plan includes tracking. ### Choose Peptide Library if - You want to track without a subscription: Pep AI's listing says tracking needs a paid plan. - You research several peptides and want cited profiles and research statistics. - You buy research compounds and want vendor listings with price per mg. - You want a web app, or inventory with run-out and reorder-by dates. ### Choose Pep AI if - You're on a GLP-1 medication and care most about food, protein, water and side effects. - You want photo meal scans and nutrition trends. - You want an Apple Watch app and an AI companion. - You want PDF reports to review with a healthcare provider. ## Key differences ### Wellness routine or research workflow Pep AI ties shots to nutrition, hydration, symptoms, sleep and mood. Peptide Library ties your log to cited research, inventory planning and vendor prices. ### Tracking on a free plan Pep AI's listing says a paid subscription is required for its tracking features. Peptide Library's free plan includes logging, schedules, reminders, the journal and body metrics. ### AI in the app Arlo answers general educational questions inside Pep AI. Peptide Library has no in-app AI; its public research profiles can be read by AI assistants through a read-only MCP server. ### Calculators Pep AI's 4.0.4 release notes say its dose calculator was removed to keep the app on the App Store. Peptide Library's calculator is on Android and on the website. ## Research Pep AI's current US description doesn't describe a compound library; its research help comes from Arlo, which answers general educational questions about peptides and GLP-1s, and from in-app help articles. Peptide Library's 200+ profiles cite PubMed, ClinicalTrials.gov, DailyMed and EMA sources and label studies by evidence type. The Research Intelligence Center adds publication and trial statistics, and you can compare peptides side by side. ## Tracking Both apps log shots and doses, give each item its own schedule and reminder times, and rotate injection sites on a body map. Pep AI adds a daily timeline, links symptoms to your dose history and estimates medication levels. Peptide Library adds on/off cycles and titration in its schedules, and an inventory that deducts stock as you log and forecasts run-out and reorder-by dates. Pep AI organises vials with photos, but its listing does not describe stock forecasting. Both track weight and progress photos. Peptide Library's journal covers mood, energy, sleep and symptoms; Pep AI covers those and adds nutrition and hydration. ## Vendors Pep AI doesn't advertise vendor listings or price comparison. If you buy research compounds and want to compare sources, Peptide Library's Shop lists vendor offers by compound and form, with price per mg after coupon codes and vendor profiles with reviews. ## Pricing Pep AI is free to download, but its listing says tracking requires a paid subscription; the App Store lists $9.99 a month and yearly plans from $29.99 to $59.99. Peptide Library's free plan includes tracking, and Pro is $4.99 a month, $39.99 a year or $89.99 once. ## Where Pep AI is stronger ### Nutrition with photo meal scans Calories, protein, carbs, fat, fiber and water, with quick log, saved meals and estimated macros from a photo. Peptide Library does not track nutrition. ### Symptoms linked to doses Log nausea, fatigue and appetite changes with severity and timing, and see them against your dose history. ### Apple Watch and an AI companion A redesigned Watch app, Live Activities and Arlo for general questions. ### Reports for your provider PDF reports that pull nutrition, sleep, side effects and progress together. ## Features | Feature | Peptide Library | Pep AI | |---|---|---| | iPhone app | Yes | Yes | | Android app | Yes | Yes | | Web app | Yes, installable | Not advertised | | Free plan | Yes (inventory: 1 peptide) | Tracking needs a subscription | | Dose logging | Yes | Yes | | History and calendar | Yes | Yes | | Recurring schedules | Yes | Yes | | Reminders | Yes | Yes | | Cycles and titration | Yes | Not advertised | | 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 | Not advertised | | Compound library | 200+ profiles | Not advertised | | 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 | Removed in 4.0.4 | | 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 | Yes | | Community | Discussions free; Q&A with Pro | Yes | | Apple Health | Yes | Yes | | Health Connect (Android) | Yes | Not advertised | | Wearables | No | Yes | | Home Screen widgets | iPhone only | Yes | | AI assistant | No | Yes | | Multi-device sync | Pro (free Android accounts sync most data) | Yes | | On-device storage | Yes | Not advertised | | Data export | Pro | PDF reports | ## Final verdict Pep AI is the better fit for a GLP-1 routine centred on food, hydration and how you feel. Peptide Library is the better fit when you research peptides, manage stock and compare vendors, and want to start without a subscription. The two don't compete for every user. Peptide Library's research pages and vendor prices are free on the web without an account, so you can use them next to any tracker. ## Frequently asked questions ### Is Pep AI free? It's free to download, but its App Store listing says a paid subscription is required for the tracking features. Plans are listed at $9.99 a month and $29.99 to $59.99 a year (US, checked October 2026). ### Does Pep AI still have a dose calculator? No. The 4.0.4 release notes say the calculator was removed to keep Pep AI on the App Store. Peptide Library's calculator is on Android and the website. ### Which app is better for GLP-1 nutrition tracking? Pep AI. It tracks calories, macros, fiber and water, with photo meal scans. Peptide Library doesn't track nutrition. ### Does Peptide Library have an AI assistant like Arlo? No, there is no AI in the app. AI assistants that support MCP can look up Peptide Library's public research profiles through its read-only MCP server. ### Is Pep AI available on Android? Yes. Pep AI: GLP-1 Peptide Tracker is on Google Play from Zode Development. Neither listing mentions a web app; Peptide Library also works in a browser. ### Can I use Pep AI and Peptide Library together? Yes. Peptide Library's library, research pages and vendor prices are free on the web without an account, so they work alongside any tracker. Comparisons use public listings and websites. "Not advertised" means no source we checked mentions the feature, not that it is missing.