Does nolvadex (tamoxifen) decrease testosterone production in males?

No. Nolvadex, a brand of tamoxifen, is a selective estrogen receptor modulator. As such, there are some small studies that suggest that it can actually increase testosterone production in med. Similarly, so can aromatase inhibitors which decrease conversion of t into e. Check out http://en.Wikipedia.Org/wiki/list_of_drugs_banned_from_the_olympics for a list of banned substances in competition & why.

Related Questions

Does nolvadex (tamoxifen) increase testosterone and increase the rate of division in cancer cells?

Yes and no. Nolvadex, aka tamoxifen is a very weak estrogen. In men it will make the brain think you have too little estrogen so the brain asks the testicles to make more testosterone that can be converted into estrogen later. In men and women, tamoxifen will block estrogen which can help treat breast cancer. Read more...