Hypokalemic paralysis is a side effect of :

Gossypol: Its use as a male contraceptive was discovered in China. Gossypol is a yellow pigment isolated from cottonseed oil. It is administered orally 10-20 mg daily for 3 months and thereafter 20 mg twice weekly. The action is directly on the seminiferous tubules inhibiting spermatogenesis without altering FSH and LH levels. The side effectssuch as weakness, hypokalaemia and permanent sterility in 20% cases limit its use. Reference: Shaw's Textbook of Gynaecology 16th edition page no 272