Well, yeah, exactly: if the "growth hormone" you're taking is the glorified and risen humanity of the Lord Jesus Christ, that will indeed cause a change in one's "physical and moral makeup".
If you think you can sanctify yourself by "increasingly ethical behavior," I have some news for you: you're a Pelagian. Sin requires a much more serious remedy than that. It requires that you be infused with God's own nature and life.
... I promised you, who have now been baptized, a sermon in which I would explain the Sacrament of the Lord's Table, which you now look upon and of which you last night were made participants. You ought to know what you have received, what you are going to receive, and what you ought to receive daily. That Bread which you see on the altar, having been sanctified by the word of God, is the Body of Christ. That chalice, or rather, what is in that chalice, having been sanctified by the word of God, is the Blood of Christ. Through that bread and wine the Lord Christ willed to commend His Body and Blood, which He poured out for us unto the forgiveness of sins. If you receive worthily, you are what you have received.-- Augustine, Sermons 227
The faithful also know a spiritual sustenance, which you too are going to know, and to receive from the altar of God. That too will be a daily bread, necessary for this life. I mean, are we going to go on receiving the eucharist when we have come to Christ himself, and when we have begun to reign with him for ever? So the eucharist is our daily bread; but we should receive it in such a way that our minds and not just our bellies find refreshment. You see, the special property to be understood in it is unity, so that by being digested into his body and turned into his members we may be what we receive. Then it will really be our daily bread.
-- Augustine, Sermons 57