What steady state means, the five half-lives rule, why early readings under-represent eventual levels, and how the DoseCurve chart shows the approach to plateau.
The single biggest reason new protocols get adjusted too early is a misunderstanding of steady state. The first few weeks of any new regimen are not representative of where you'll end up — you're still climbing. This page explains why, and how to use the DoseCurve chart to see when the climb is over.
Steady state is the point at which the amount of compound entering your system per dosing cycle equals the amount being cleared per cycle. Once you're there, every cycle looks identical: same peak, same trough, same average. The curve has stopped climbing on average — it just oscillates within a fixed envelope.
Before steady state, each successive dose lands on top of more leftover compound than the one before. Your average level rises with every cycle until clearance catches up with input.
A protocol reaches approximately 97% of its eventual steady-state level after five half-lives of repeated dosing. The rule is symmetrical with the wash-out rule — it takes about five half-lives to clear a single dose, and about five half-lives to fully accumulate to plateau.
Worked examples:
| Compound | Half-life | Time to steady state |
|---|---|---|
| Testosterone propionate | ~1.5 days | ~7–8 days |
| Testosterone enanthate | ~7 days | ~5 weeks |
| Testosterone cypionate | ~8 days | ~6 weeks |
| Testosterone undecanoate (oil) | ~25 days | ~4–5 months |
This is why a cypionate protocol checked at week two is meaningless. You're at roughly 50% of your eventual level. Whatever serum number you got, the real long-term number will be roughly twice as high.
The most common pattern: someone starts a new protocol, draws bloodwork at three or four weeks, sees a number that looks low, and assumes the dose is too small. They up the dose. By week eight, the original dose would have produced an in-range result — but they're now overshooting at the higher dose, and chasing side effects they wouldn't otherwise have had.
Standard pharmacology teaching is to allow a protocol to approach steady state before drawing baseline bloodwork — typically at least four to five half-lives. Specific timing on any individual protocol is a decision for the prescribing clinician.
Open DoseCurve, enter your protocol, and look at the chart over a long time window (90 or 180 days). You'll see the trough line — the dips between doses — climb steadily for the first several weeks, then flatten out. The flat region is steady state.
The dashboard surfaces Time to Steady State directly as an analytic. It's calculated from the half-life you've set: change the half-life and the time updates accordingly. Use it as your "don't bother drawing bloodwork before this date" marker.
Pharmacokinetics rewards waiting. The body is slow, and trying to read its tea leaves before it's done brewing leads to bad decisions. The DoseCurve chart exists in large part to make the climb to steady state visible, so you can see — not just trust — that the protocol you set on day one is the protocol you'll be living with on day forty.
DoseCurve is an educational tool. Nothing on this site is medical advice. Always consult a qualified clinician before starting, changing or stopping any protocol.