11.   Testosterone is a naturally occurring hormone responsible for such male characteristics as a deep voice and facial hair.

12.   The drug supplements a naturally occurring hormone made in the kidneys to stimulate red blood cell production and correct anemia because of kidney failure.

13.   The FDA has declared this drug safe for humans because it is similar to a naturally occurring hormone in dairy cows.

14.   The miracle stuff I bought is melatonin, a naturally occurring hormone secreted by the pineal gland, a tiny mid-brain structure.

15.   Androstenedione supplements are made of a naturally occurring steroid hormone.

16.   Androstenedione supplements are made of a naturally occurring steroid hormone the body uses to make testosterone.

17.   Both are naturally occurring hormones that can be artificially ingested to boost performance.

18.   Epinephrine, a naturally occurring hormone, is used to increase blood flow and restore breathing.

19.   EPO, or erythropoietin, is a naturally occurring hormone that boosts the red blood cell count, increasing endurance.

20.   She was later notified that her test revealed an unusually high ratio of testosterone, a naturally occurring hormone that also is taken in concentrated form to improve performance.