Primobolan Dosage & Cycle Guide: Injectable and Oral Protocols (2026)

Written by: Coach Alex Reid — IFBB Pro Bodybuilder, BSc Sports Science (Loughborough University), UKSCA Certified S&C Coach

Medically reviewed by: Dr. James Hargreaves — MBChB, MRCP — Consultant in Internal Medicine, Manchester

Last updated: 26 June 2026

Primobolan is a compound where dosing decisions significantly affect whether you get meaningful results or waste an expensive compound. Too low a dose produces negligible effects; too short a cycle wastes the slow-onset build-up period. This guide covers evidence-informed dosing for both injectable and oral forms, complete cycle protocols, and how to stack Primobolan with other compounds to maximise its unique properties.

Primobolan Dosage Reference Table

Form Experience Level Dose Frequency Cycle Length
Injectable (Enanthate) Beginner 300–400 mg/wk Once or twice weekly 12–16 weeks
Injectable (Enanthate) Intermediate 400–600 mg/wk Twice weekly 12–20 weeks
Injectable (Enanthate) Advanced 600–1000 mg/wk Twice weekly 16–20 weeks
Oral (Acetate) Men 100–150 mg/day Daily (split doses) 8–12 weeks
Oral (Acetate) Women 25–75 mg/day Daily 6–10 weeks

Key point on oral Primobolan dosing: Due to the approximately 30–50% oral bioavailability, oral Primobolan at 100 mg/day delivers significantly less active compound than 100 mg of injectable Primobolan. Men seeking equivalent effect to 400 mg/week injectable would require 100–150 mg/day oral. The injectable form is substantially more cost-effective per unit of active compound delivered.

Beginner Cutting Cycle: Primobolan + Testosterone

Week Testosterone Enanthate Primobolan Depot AI Notes
1–14 400 mg/wk 400 mg/wk Aromasin 12.5 mg EOD Both injected twice weekly; may combine in one syringe
PCT (wk 16–20) Stop wk 14 Stop wk 14 Nolvadex 40/40/20/20 Excellent lean mass retention from cut

Intermediate Competition Prep Cycle

Week Test Prop Primo Depot Anavar (finishing) Support
1–16 100 mg EOD 600 mg/wk Aromasin EOD; blood monitoring
12–16 100 mg EOD 600 mg/wk 50 mg/day TUDCA 500 mg/day during Anavar phase
PCT (wk 18–22) Stop wk 16 Stop wk 16 Stop wk 16 Nolvadex 40/40/20/20

Anavar added in the final 4 weeks enhances hardness and vascularity ahead of contest date. See our Anavar complete guide for dosing details and our competition prep guide for full periodisation context.

Women's Primobolan Protocol

Week Oral Primobolan (Acetate) Monitoring
1–2 25 mg/day Assess for early virilisation signs
3–8 50–75 mg/day if tolerating Monitor voice, clitoral size, hair growth
Post-cycle Stop; no PCT required Most virilisation effects reverse within 2–4 weeks if caught early

Does Primobolan Require PCT?

Yes — despite its mild reputation, Primobolan suppresses LH and FSH production. HPG axis recovery without PCT will occur but may take months. A standard Nolvadex 40/40/20/20 mg PCT protocol supports faster and more complete recovery. See our complete PCT guide.

AI Requirements with Primobolan

Primobolan itself does not aromatise. When combined with a testosterone base (which does aromatise), an AI is required for the testosterone component. The AI requirement is often reduced compared to testosterone-only cycles at equivalent doses, as Primobolan competes with oestrogen-active compounds for receptor binding. Monitor oestradiol via bloodwork rather than using a fixed AI dose. See our Arimidex products.

Frequently Asked Questions

Can Primobolan be used solo (without testosterone)?

Technically possible but not recommended for men. Primobolan suppresses endogenous testosterone without replacing it aromatically, which can lead to low oestrogen symptoms (joint pain, mood disturbance, reduced libido) even while maintaining androgen levels. Women can use oral Primobolan as a standalone compound. Men should always include a testosterone base.

Is 200 mg/week Primobolan enough?

For most men seeking meaningful physique changes, 200 mg/week of injectable Primobolan is likely insufficient. This dose may produce some benefit in body recomposition when in a caloric deficit, but the dose-response curve for Primobolan favours 400+ mg/week for clear anabolic effect. This is why Primobolan is expensive to run effectively.

How does oral Primobolan compare to oral Anavar?

Both are mild, dry oral anabolics with lower liver toxicity than 17aa compounds. Anavar's bioavailability is higher and its potency per milligram is greater. Oral Primobolan is genuinely not 17aa-alkylated and thus has even lower liver impact, but requires higher doses. For most athletes, injectable Primobolan is the superior choice over oral Primobolan if the injectable is available.

Medical Disclaimer: This guide is for informational and harm reduction purposes only. Primobolan requires PCT for men and regular monitoring for virilisation signs in women. Consult a medical professional before use.

About the Author: Coach Alex Reid is an IFBB Professional bodybuilder and UKSCA-certified S&C coach with extensive experience guiding UK competitive athletes through cutting and competition prep phases.

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