Methodology and Limitations
Important. This page is included because charts and estimates in health-related apps can be misunderstood. Any estimate shown by the service is non-clinical, informational, and subject to important limitations.
1. Purpose of this page
This page explains, at a high level, how user-facing trend charts, summaries, reminder logic, and any optional estimates are generated within GLPzy. It also sets out what those outputs are not designed to do.
2. Inputs used by the service
Depending on the features enabled, visualisations and summaries may be based on:
- medication name selected by the user;
- dose amount entered by the user;
- date and time records entered by the user;
- historical logs maintained by the user;
- generalised assumptions used to generate user-facing informational views.
3. Estimated Exposure Trend methodology
Estimated Exposure Trend is a relative personal-tracking estimate derived from the dose timing the user logs, the selected medicine context, and a parameterised absorption-and-elimination model. It is intended to help users review timing patterns in their own records, not to provide clinical measurement.
estimated level(t) = Σ doseMg × ka / (ka − ke) × (e^(−ke×t) − e^(−ka×t))
ke = ln(2) / half-life and ka is solved numerically so the model reaches the assumed time-to-peak for the selected medication context.
- Historical views are built from logged taken-dose events plus medication-specific half-life and time-to-peak assumptions.
- Projected views reuse the same model parameters, then extend the future timeline with synthetic doses based on the scenario selected in the app.
- The chart uses a solid line for historical output and a dashed line for projection so the boundary at today stays explicit.
- The projected chart colour-codes history and projection by dose level so dose-step changes remain visible during review.
- If the optional weight overlay is enabled, it is drawn on a separate visual scale so weight review does not alter the Estimated Exposure Trend calculation.
- It is not a measured blood concentration.
- It is based on a simplified model.
- Oral and injectable semaglutide are not compared on a raw mg basis.
- Do not use this for dosing decisions.
- Projected views may assume that the current dose continues, that no future doses are added, or that a user-selected next dose date and amount become the new repeating anchor.
- If a schedule appears overdue, GLPzy requires the user to choose how the projection should restart rather than silently guessing.
- For custom or compounded treatments, estimated-level review is available only when the user has entered a positive half-life for personal tracking. If no half-life is present, the estimate is suppressed.
- It is not a serum assay, blood test, or direct measurement of medication in the body.
- It does not account for all individual factors that can affect absorption, metabolism, tolerance, formulation handling, or response.
- It does not replace approved product information or clinician instructions.
4. Outputs that may be shown
Depending on product configuration, the service may display timelines, weekly summaries, schedule coverage views, reminder histories, streaks, trend charts, weight views, symptom summaries, or informational estimates based on prior entries.
5. Key limitations
- Any estimate is not a direct measurement of medication in the body.
- Any estimate is not a serum concentration reading, blood test, or laboratory result.
- Any estimate does not account for all individual factors that may influence absorption, tolerance, metabolism, or response.
- The service does not validate or verify the medical accuracy of user-entered data.
- The service may not reflect clinician-specific instructions, missed doses, partial doses, or off-label treatment plans unless accurately entered and supported by product logic.
6. What the outputs must not be used for
You must not use charts, visualisations, summaries, reminders, or estimates generated by the service to make medication, treatment, or diagnosis decisions. They must not be used as a substitute for clinical advice or approved product information.
7. Visible safety framing
GLPzy pairs the historical and projected Estimated Exposure Trend features with explicit in-app safety wording, including:
Estimated Exposure Trend is a relative personal-tracking estimate.It is not a measured blood concentration.It is based on a simplified model.Oral and injectable semaglutide are not compared on a raw mg basis.Do not use this for dosing decisions.Projected values follow the selected scenario only and may differ from real-world timing or response.Always check with your clinician before making medical decisions.
8. References and bibliography
- CDC: About Body Mass Index (BMI) — BMI definition, formula, and screening framing used in GLPzy.
- CDC: Adult BMI Categories — adult BMI category ranges and screening interpretation context.
- CDC: BMI Frequently Asked Questions — hand-calculation formula and adult-versus-child interpretation context.
- FDA: Wegovy prescribing information — semaglutide injection product information and pharmacokinetic assumptions referenced by the estimate.
- FDA: Zepbound prescribing information — tirzepatide weekly product information and pharmacokinetic assumptions referenced by the estimate.
- FDA: Mounjaro prescribing information — U.S. tirzepatide product information referenced by the in-app leaflet links.
- FDA: Ozempic prescribing information — U.S. semaglutide injection product information referenced by the in-app leaflet links.
- FDA: Rybelsus prescribing information — U.S. semaglutide tablet product information referenced by the in-app leaflet links.
- FDA: Saxenda prescribing information — liraglutide daily product information and pharmacokinetic assumptions referenced by the estimate.
- FDA: Victoza prescribing information — U.S. liraglutide product information referenced by the in-app leaflet links.
- FDA: Trulicity prescribing information — U.S. dulaglutide product information referenced by the in-app leaflet links.
- emc: Wegovy Summary of Product Characteristics (SmPC) — UK semaglutide product information referenced by the in-app leaflet links.
- emc: Mounjaro Summary of Product Characteristics (SmPC) — UK tirzepatide product information referenced by the in-app leaflet links.
- emc: Ozempic Summary of Product Characteristics (SmPC) — UK semaglutide injection product information referenced by the in-app leaflet links.
- emc: Rybelsus Summary of Product Characteristics (SmPC) — UK semaglutide tablet product information referenced by the in-app leaflet links.
- emc: Saxenda Summary of Product Characteristics (SmPC) — UK liraglutide product information referenced by the in-app leaflet links.
9. Versioning and change control
Where the service materially changes the way it generates user-facing visualisations or estimates, we may update this page to reflect the revised approach. Material changes may affect how prior outputs are displayed or interpreted.
10. Product and legal review
If the service introduces features that move beyond tracking, journaling, reminders, exports, and informational summaries, additional validation, legal review, or regulatory analysis may be required before such features are offered in particular jurisdictions.
11. Questions
Questions about this page may be directed to [email protected] or [email protected], as appropriate.