Ostarine is suppressive to testosterone
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2602589/
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Male hormonal contraception
Despite prevalent use of oral contraceptives for women, no oral pharmacologic option has been approved for men. Hair et al. [Hair et al., 2001] found that desogestrel, an oral synthetic progestin, in combination with a transdermal testosterone patch, reversibly suppressed spermatogenesis, but was not as efficacious as combination testosterone injection regimens. Preclinical studies in our laboratory have shown that propionamide SARMs suppress luteinizing hormone (LH) and follicle stimulating hormone (FSH) through the hypothalamus-pituitary-testis axis in rats, thus decreasing testosterone in a dose-dependent manner [Chen et al., 2005a]. Furthermore, spermatogenesis was found to be significantly decreased with 1 mg/day treatment for 10 weeks in these animals with the SARM, C-6 (see literature for structure). Studies with the SARM, LGD2226, assessing the effects on mating behavior of rats, show maintenance of libido and sexual function in rats [Miner et al., 2007]. As a whole, these data are encouraging towards the development of a SARM as a male contraceptive pill."
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