PCT (Post Cycle Therapy)
When to Start PCT After a Steroid Cycle: Timing by Compound
Mar
Why Timing Is the Most Critical PCT Variable
The single most common PCT mistake — after simply not doing PCT at all — is starting it too early. If exogenous androgens are still present at meaningful concentrations in the bloodstream when SERMs are initiated, the suppressive androgens will prevent the HPTA from responding to the SERM’s signal. The SERMs are effectively wasted, and the user enters a partially recovered but still suppressed state when the compounds finally clear. Correct timing means waiting until exogenous androgen blood levels have dropped below the threshold that maintains HPTA suppression — approximately 40–60 mg/dL testosterone equivalent.
The Half-Life Rule
A compound’s half-life determines how long it takes to clear the system sufficiently to begin PCT. The standard guideline is to wait approximately 4–5 half-lives after the last dose before starting SERMs, as this represents the point at which approximately 90–97% of the compound has been eliminated. In practice, the field uses simplified, evidence-based waiting periods:
PCT Start Time by Compound
| Compound | Ester / Form | Half-Life | Wait Before PCT |
|---|---|---|---|
| Testosterone Enanthate | Enanthate | 7–10 days | 14 days |
| Testosterone Cypionate | Cypionate | 8–12 days | 14 days |
| Testosterone Propionate | Propionate | 1–3 days | 3 days |
| Testosterone Suspension | Water (no ester) | ~1 day | 1 day |
| Nandrolone Decanoate (Deca) | Decanoate | 6–12 days | 21–28 days |
| Nandrolone Phenylpropionate | Phenylpropionate | 4–6 days | 5–7 days |
| Boldenone Undecylenate | Undecylenate | ~14 days | 21 days |
| Trenbolone Acetate | Acetate | 1–2 days | 3 days |
| Trenbolone Enanthate | Enanthate | 7–10 days | 14 days |
| Masteron Propionate | Propionate | 1–3 days | 3 days |
| Masteron Enanthate | Enanthate | 7–10 days | 14 days |
| Dianabol (oral) | Oral C-17aa | 3–5 hours | 24–48 hours |
| Anavar (oral) | Oral C-17aa | 8–9 hours | 24–48 hours |
| Winstrol (oral) | Oral C-17aa | 9 hours | 24–48 hours |
| Anadrol (oral) | Oral C-17aa | 8–16 hours | 24–48 hours |
The Nandrolone Problem
Nandrolone decanoate (Deca-Durabolin) is the compound that trips up the most users on PCT timing. Its long decanoate ester means it remains active in meaningful concentrations for 3–4 weeks after the last injection. Users who follow the standard “wait 14 days” rule after a Deca cycle start PCT far too early. The recommended wait is 21–28 days after the last Deca injection. This is why Nandrolone Phenylpropionate (NPP) — with its shorter ester — is sometimes preferred by those who want a shorter post-cycle clearance window.
Mixed Ester Cycles
When a cycle includes compounds with different ester lengths (e.g., Testosterone Enanthate + Trenbolone Acetate), the PCT wait time is governed by the longest-acting compound, not the shortest. In this example: last Testosterone Enanthate injection determines timing (wait 14 days), regardless of when Trenbolone Acetate was last injected.
Sustanon 250 Timing
Sustanon is a blend of four testosterone esters (propionate, phenylpropionate, isocaproate, decanoate). Because it contains the decanoate ester, clear timing is similar to Deca: wait 21 days after the last Sustanon injection before starting PCT. Many users underestimate this, applying the enanthate/cypionate 14-day rule and starting too early.
Using HCG to Bridge the Gap
For long-ester cycles where the post-cycle waiting period is 2–4 weeks, this gap represents a prolonged hypogonadal window. HCG used during this bridge period maintains testicular function and testosterone production while waiting for exogenous androgens to clear, significantly improving comfort and recovery outcomes. Full protocol at HCG in PCT guide.
Full PCT Framework
For drug selection, doses, and complete cycle-specific protocols, read our PCT Complete Guide and PCT Protocol for Steroid Cycles.
📚 Related Pillar Guides: Testosterone Complete Guide • Winstrol Complete Guide
