Anabolic steroids. Part 2: the disposition of ethylestrenol in the rat

1. The absorption, distribution, metabolism and excretion of [3H]ethylestrenol were studied in the rat. 2. Approximately one third of an intragastric dose was absorbed; 17% of the dose was excreted in urine and 83% in faeces within 10 days. 3. The dose is distributed throughout the rat, and kidney and liver were found to contain respectively 2.5-3 and 5-7 times the average specific activity of all other tissues. 4. Unchanged ethylestrenol was the only component detected in urine. Ethylestrenol was also found in faeces, along with two different dihydroxylated dihydro derivatives and one trihydroxylated dihydro derivative.