A peptide tracker app for complete protocols.
Halflife - Peptide & GLP-1 Log tracks injection schedules, syringe calculations, vial inventory, sites, symptoms, and estimated remaining-level curves on iPhone. The current App Store listing says 45 substances; the public website database currently documents 44.
estimated pharmacokinetic curves for each compound in your protocol.
Halflife displays the active medication level for each compound based on published pharmacokinetic half-life data. Users running multiple compounds simultaneously — such as tirzepatide, BPC-157, and testosterone — can view overlapping estimated concentration curves from a single dashboard. The app calculates remaining active percentage at any point in time using first-order elimination kinetics.
For compounds where plasma half-life and biological effect duration differ significantly (such as BPC-157 and TB-500), a second curve displays the estimated biological signalling window separately from plasma clearance.
Injection logging and site rotation
Log each injection dose, compound, and injection site in three taps. A body map tracks the last injection location per compound and suggests the next rotation point. Halflife stores a complete injection history with timestamps, dose amounts, and site locations for each compound in the protocol.
Reconstitution and syringe calculator
Enter the vial size (in mg) and diluent volume (in mL). The calculator returns draw-volume arithmetic in both mL and insulin-syringe units from the values entered. Verify the product, inputs, units, and instructions independently.
Vial inventory and supply tracking
Track remaining volume per vial for each compound. The app calculates a days-of-supply countdown based on the current dosing schedule and alerts before stock runs out mid-protocol. Each vial entry records reconstitution date, remaining volume, and projected depletion date.
Weight logging and progress charts
Log weight entries and set a target goal. The app displays goal percentage, total change, and a sparkline trend chart on the Today screen. Weight data is correlated alongside injection events and compound timelines for longitudinal tracking.
Side effect and symptom logging
Record side effects and symptoms alongside injection events. Each entry is timestamped and linked to the active compound stack, making it possible to identify patterns between dose changes, compound additions, and reported symptoms over time.
Injection schedule reminders
Set configurable push notification reminders for each compound based on its dosing frequency. Reminders are scheduled per-compound, not globally — a weekly tirzepatide reminder operates independently from a daily BPC-157 reminder.
Apple Health integration
Connect Apple Health to import HRV, resting heart rate, deep sleep percentage, and step count data. Health metrics are displayed alongside the compound stack timeline, allowing users to observe correlations between protocol changes and biometric trends.
Protocol adherence streak
Halflife tracks a daily adherence streak tied to the actual protocol schedule — not a fixed calendar. If no injection is due on a given day, the streak is maintained by participating in the daily community poll on the Discover screen.
PDF export for healthcare providers
Generate a one-tap PDF export of the full protocol history — compounds, doses, injection dates, adherence rate, and weight trajectory — formatted for use during a clinical appointment. The export includes a timeline view of all logged injections and dose changes.
Daily community polls
A new question is published to the Discover screen every day. Users vote and see how other active protocol trackers answered as a continuously updated estimate. Results are only visible after the user has voted.
44 compounds with verified half-life data across 8 categories.
Every half-life value in the Halflife compound database is sourced from FDA prescribing labels, published clinical trial data, or peer-reviewed pharmacokinetic studies. The database includes GLP-1 receptor agonists, peptides, testosterone and TRT compounds, GH secretagogues, and longevity-related compounds.
Brand names supported: Ozempic, Wegovy (semaglutide) · Mounjaro, Zepbound (tirzepatide)
Weight, inventory, and community — in one place.
Core protocol records are stored locally; optional features transmit limited data.
Halflife stores all dose logs, weight entries, injection sites, side effects, and protocol details exclusively in local device storage. No account creation is required. No login is required. Core protocol records are not transmitted unless the user enables optional research contribution. Poll votes, subscription-management data, and opted-in research fields may be transmitted as described in the Privacy Policy. Users may opt in to contribute anonymized protocol data to Halflife Labs research — this is strictly optional and disabled by default.
Read the full Privacy Policy →Halflife is a tracking tool, not a medical device.
Halflife is designed for personal protocol logging and reference purposes only. The app does not provide medical advice, diagnose conditions, or recommend dosages. Estimated concentration curves are mathematical estimates based on published pharmacokinetic half-life data — they do not represent measured blood levels. All dosing, compound selection, and protocol decisions should be made in consultation with a licensed healthcare provider. Halflife Labs is not responsible for health outcomes resulting from self-administered protocols.