For post-cycle therapy, your dosage should depend on the cycle. If the cycle was short (6-8 weeks) with one steroid or small steroids dosages you should use 20 mg for 14 days. If your cycle was advanced, the dosage can be up to 50 mg per day for 6 weeks with gradually decreasing dosages. Also, you can use a combination of Tamoxifen and Clomid (Clomiphene) after advanced cycles.
The same as with Clomid it’s very important to start using Tamoxifen timely. After oral only cycles like Turinabol, Winstrol and Dianabol you should start taking it a day after your cycle is completed. If a cycle contains short-lived esters, start taking Tamox 3 days after the cycle. If a cycle includes long esters you should wait 14 days before using it.
For the purpose of decreasing estrogenic side effects during an androgenic anabolic steroid cycle, the optimal dosage is from 10 to 20 mg per day. If this dosage does not help to protect from gynecomastia you should consider using aromatase inhibitors (AI) such as Anastrozole or Proviron.