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Custom compounds
The app ships with the major GLP-1s built in (Tirzepatide, Semaglutide, Liraglutide, Dulaglutide, oral Semaglutide, Retatrutide). For anything else — research peptides, prescription medications, supplements you dose on a schedule — add a custom compound.
When to add one
Common reasons:
- Other peptides: BPC-157, TB-500, GHK-Cu, Cagrilintide, Survodutide, etc.
- Compounded versions with non-standard doses or kinetics that warrant separate tracking.
- Hormone replacement therapy: testosterone, estradiol, progesterone, T3/T4, etc.
- Prescription medications with a meaningful half-life curve: psychiatric, cardiovascular, etc.
- Supplements you treat as scheduled rather than as needed.
Plan limits
Free tier: no custom compounds. Premium: up to 3 custom compounds. Unlimited: no limit.
How to add
- Profile → Compounds → + Add compound.
- Fill in the fields:
- Name — what you'll call it (e.g., "BPC-157", "Testosterone Cypionate").
- Half-life — in days. See "Picking a half-life" below.
- Dose interval — how often you dose, in days. Daily =
1, weekly =7, every 4 days =4. - Kinetics shape — bolus, sub-Q, or depot. See Kinetics shapes.
- Dose unit — mg, mcg, iu, or ml.
- Color (optional) — for the dashboard chart.
- Save.
The new compound appears in your Compounds list, ready to dose against.
Picking a half-life
For peptides, look up the published half-life in research literature. Some common ones:
| Compound | Typical half-life | Notes |
|---|---|---|
| BPC-157 | ~4 hours (~0.17 days) | Short. Often dosed daily or BID. |
| TB-500 (Thymosin Beta-4) | 1–2 days | |
| Cagrilintide | ~7 days | Weekly. |
| Survodutide | ~6 days | Weekly. |
| Testosterone Cypionate | ~8 days | Common HRT compound. |
| Estradiol Valerate | ~3.5 days | |
| L-Thyroxine (T4) | ~7 days | Long. |
| Liothyronine (T3) | ~1 day | Short. |
| Tesamorelin | ~30 min | Very short — daily dosing. |
| Cortisol (hydrocortisone) | ~1.5 hours |
Half-life isn't always tabulated. For a compound you can't look up:
- Daily dosing → start with 1 day half-life. The curve will look like a sawtooth.
- Weekly dosing → 5–7 days.
- Twice-weekly → 3–4 days.
You can change the half-life later if the curve doesn't match how the compound feels.
Picking a kinetics shape
Three options. Pick based on how it absorbs, not how long it lasts:
- Bolus — instant peak. IV-administered drugs, or anything that hits peak within minutes.
- Sub-Q (default) — rises over a few hours, then declines. Almost all self-injected peptides.
- Depot — slow-release, lower peak, longer tail. Long-acting weeklies in oil suspension.
If you don't know, sub-Q is right ~90% of the time. See Kinetics shapes for the math.
What you can't do with custom compounds
The endogenous biomarker simulation doesn't include custom compounds. The simulation engine has built-in pharmacology models for the canonical GLP-1 catalog only. Your custom compound's PK curve will plot on the dashboard, but it won't drive simulated cortisol, glucose, or insulin responses.
Receptor mapping isn't possible — there's no way for the app to know that BPC-157 hits VEGF or GHK-Cu hits copper transport. Only catalog peptides have receptor metadata.
Pharmacological interactions with catalog compounds aren't modeled.
What custom compounds do give you:
- A real PK curve on the dashboard.
- Per-compound reminders.
- Inclusion in the dose log and pattern insights (correlations between dose and weight / symptoms still work).
- Inclusion in the data export.
Reminders
Custom compounds get the same reminder system as built-ins:
- Toggle Reminder on for the compound.
- Pick a time of day.
- The reminder fires only on dose days, computed from your interval and last logged dose. Smart-skip suppresses the reminder if you've already logged today.
Editing or deleting
Tap a compound to edit any field. Half-life, kinetics shape, and interval can all be changed retroactively — the dashboard recomputes the curve with the new parameters.
Deleting removes the compound but doesn't delete its dose history. The dose entries become orphans (still in your data, but with no associated curve). If you re-create a compound with the same name, the orphan doses don't auto-rejoin — they stay as orphans. To re-attach them, edit each affected dose entry.
Common questions
"Why doesn't my custom compound show up in the simulation?" The simulation needs receptor / target metadata that only the canonical catalog has. Custom compounds don't have that, by design — we'd be making up biology if we tried to fit one to a generic peptide model.
"Can I make a custom version of Tirzepatide for compounded products?" Sure, but we recommend using the built-in Tirzepatide entry for standard compounded versions — the kinetics are the same. Use a custom only when the formulation is truly different (e.g., long-acting depot version, atypical concentration).
"What if my compound has multiple compartments / non-first-order kinetics?" The app uses single-compartment first-order kinetics. Multi-compartment (alpha + beta) PK isn't modeled. For most exogenous peptides, the single-compartment approximation is fine. If you're tracking something where multi-compartment matters (lithium, digoxin), the app's curves will be approximate.
Related
- Log a dose — using the compound after you've added it.
- Kinetics shapes — bolus, sub-Q, depot.
- Plans & billing — custom compound limits per tier.