Should you decide to use anti estrogens always consult a licenced physician. Anti estrogen, aromatase inhibitors, estrogen management, female hormone blockers, there are many available on the market; Arimidex, Nolvadex, Femara, Letrozole, hcg, Clomid. Estrogen causes many side effects that athletes want to avoid when on steroid cycle, the side effects include, but are not limited to water retention, gynecomastia etc. Anti estrogens like arimidex, letrozole, nolvadex, proviron, masteron, aromasin are used during the cycle as well as for PCT. They limit the conversion of testosterone into estrogen ( aromatization ) and in this way prevent possible unwanted side effects. With anabolic steroids it is like with any other medication, it has it favorable effects, can cure many diseases and conditions, but also carries about side effects one should be aware of, so that at the onset the dosage can be adjusted or a secondary aid added to counter those side effects. The side effects of anabolic steroids are dose related, the higher the dose the more likely they are to occur. Side effects also differ from one person to another, while some get them at the slightest hint of using steroids others can use elaborate stacks in long term steroid cycles and not be affected. There are many mads that are used to counter the side effects that are usually estrogen related. As testosterone levels rise estrogen levels rise also bringing about the unwanted bloat, female pattern fatty tissue distribution, hair loss, increased bodily and facial hair growth, deeper voice, acne. Nolvadex was one of the first pills used by bodybuilders, tamoxifen citrate was very effective and one of the few tablets used to counter the side effects of anabolic steroids in the eighties. Clomid was also used back then, clomiphene citrate comes in dosage of 10 or 20 mg tablets. In the last decade new more effective tablets emerged, but they were also considerably more expensive wich kept clomid and nolvadex among the most used tablets to counter estrogen buildup from anabolic steroid cycles. Arimidex was the first and was at the beginning only introduced in Europe, after it's sucess it found it's way to the USA and rest of the world. Anastrazole is very effective, but also up to 20 times more expensive than nolvadex. More known in the USA are Femara and Letrozole. Dosage should be adjusted throughout the steroid cycle, using as little as possible to prevent side effects. The antiestrogen pills are also used as part of the post cycle therapy or PCT as it is known in the bodybuilding circles. It helps the body restore it's former natural testosterone levels as the testes are suppressed due to exogenous testosterone derived from anabolic steroid use. Once the testes regain their usual size and function the muscle gains made on the steroid cycle can be kept to the full extent.