A hormone or vitamin (7)
I believe the answer is:
steroid
(Other definitions for steroid that I've seen before include "muscle-building compound" , "Organic compound" , "Body-building drug" , "Controversial body-builder" , "Type of hormone" .)
I believe the answer is:
steroid
(Other definitions for steroid that I've seen before include "muscle-building compound" , "Organic compound" , "Body-building drug" , "Controversial body-builder" , "Type of hormone" .)