~1/3 citrate, same as tamoxifen citrate. However, from the info I've found it appears that prescription 50 mg Clomid tabs have 50 mg of Clomiphene Citrate. This is unlike Nolvadex--a 20 mg tab actually has 30.4 mg of Tamoxifen Citrate. I'm not sure, though. Either way, the molecular weights show that 1/3 is citrate.