Possible Interaction: Progesterone and Testosterone Propionate

“Concurrent administration of progesterone inhibited fighting behavior activated by low, but not moderate to high doses of testosterone propionate.”

“Cimetidine, progesterone and cannitracin, but not tolazoline, significantly decreased the weight and DNA content of the hyperplastic prostate induced by TP.”

“Regrowth of sebaceous glands after castration and substitution with testosterone propionate or dihydrotestosterone could be inhibited by topical PM and PRO.”

“Positive correlations between levels of aggression and social preference for an opponent were found in both sexes, although correlations only reached statistical significance when progesterone was given in addition to TP.”

“ Progesterone when given in addition to TP facilitated receptive and proceptive behaviors, but reduced levels of aggression.”

“Assessment of the feedback effects of exogenous gonadal steroids on pituitary gonadotropin release in castrated adults indicated that injection of 125 micrograms TP further increased the already elevated post-castration levels of LH and FSH in mice neonatally exposed to progesterone.”

“The nonaromatizable androgen, DHTP, does not reduce weight gain even in very high doses, and concurrent progesterone injections reverse the weight-reducing actions of high TP doses.”

“When treated for 3 days with either 50 or 150 μg of testosterone propionate (TP) and given progesterone prior to behavior testing on day 4, female rats with septal lesions showed a higher mean LQ than sham-operated rats.”

“In addition, the administration of TP concurrently with progesterone prevented the latter from eliciting nest building.”

“It has been known for some time that the administration of testosterone propionate or testosterone propionate plus progesterone can induce lordosis behavior in female rats much as can estrogen treatment.”

“However, progesterone given 1 hr before TP only delayed the effect of the androgen: The usual cyclic increases did not occur during the first 84 hr, but essentially a complete response occurred between 84 and 156 hr.”