It is known as Hatschek's pit and has been found to react positively to antibodies against substance P, met-enkephalin, cholecystokinin (CCK), mammalian luteinizing hormone (LH), and the enzyme aromatase (P450ₐᵣₒ), which converts certain androgens into estrogens (see Chapter 3).
Source: wiktionary
However, high levels of the nonaromatizable androgen dihydrotestosterone and of sex-hormone binding globulin that inhibit fat accumulation in the abdomen might also contribute to reducing the waist.
Source: wiktionary
Indeed, one popular thread on looksmax.org is devoted to “pubertymaxxing,” complete with “an introduction into androgens and growth factors, and how to apply them.”
Source: wiktionary