Cyclofenil is a new diphenyl ethylene derivative related to stilboestrol without oestrogenicity but with marked effects on connective tissue metabolism. The drug has been tested, in a daily dose of 200mg X3, in six patients with progressive systemic sclerosis (PSS) to analyze the expected beneficial effects on the PSS symptoms. The typical skin hardness, joint and muscle rigidity, and reduced breathing capacity were improved to varying dgrees. The only side-effect was a slight transient liver enzyme elevation in 1 out of 6 patients. A slight increase was found in urinary calcium and hydroxyproline excretion. In several cases serum calcium, cholesterol, triglyceride and in some cases the serum uric acid levels were decreased. The ANF titres diminished to varying degrees in 4 out of 6 patients. These results indicate that further detailed clinical and laboratory studies on the therapeutic potential of cyclofenil in PSS and other diseases affecting connective tissue seen to be justified.

Cyclofenil is the least popular of the three Selective Estrogen Receptor Modulators (SERM) being used in athletics today. SERMs cause ovulation in women and (more importantly to us) increase testosterone and other beneficial hormones. This drug actually works by simulating the effects of testosterone via inhibiting the negative feedback loop caused by estrogen, with regards to testosterone production. This in turn causes the increased secretion of Gonadotropin Releasing hormone, which increases output of Luteinizing Hormone which increases secretion of testosterone from your testes.

The results indicate that cyclofenil, paradoxically, has two opposing actions on the hypothalamic-hypophyseal axis, one of them is estrogen-like, in that it depresses serum FSH levels and competitively binds to breast tissue (this is good, remember), and the other action is antiestrogen-like, in that it depresses serum PRL levels and raises LH levels (4). Overproduction of prolactin, will suppress Testosterone, and could induce lactation in male breast tissue.

Source: steroid.com