Primobolan dosage and administration depends heavily upon which form is being used: oral or injectable. Medical prescription Primobolan dosages outline 200mg as a first dosage, followed with 100mg every week for the complete duration of therapy. The medical condition being treated would determine what the actual full Primobolan dosage is. The range can be anywhere from 100mg every one or two weeks to 200mg every two to three weeks. Medical guidelines for oral Primobolan dosages call for 100 – 150mg per day for no longer than 6 – 8 weeks of consistent use.