A hard flaccid penis is a fairly common condition experienced by men. In order to reverse it, one has to understand the biochemical processes that caused it in the first place.
If one masturbates chronically or use penile enlargement techniques, there is a fair chance that he will eventually injure the penile tissues beyond the point of self repair. Over-masturbation, over-ejaculation or other stressors over-discharge the brain's acetylcholine, dopamine, and serotonin nerves systems. An excessive Prostaglandin E-2 release into the blood and tissues is also observed. A great problem associated with over-masturbation and/or over-ejaculation is the deactivation of the Central Nervous System (CNS). It drives the hypathamalus and anterior pituitary, the master of the endocrine function for hormonal production, and powers the entire endocrine function through the parasympathetic nervous division. Over-masturbation or over-ejaculation consumes testosterone and leaves nothing to recharge the CNS and the parasympathetic backup battery.
The production of your androgen hormones - DHEA, testosterone, androstenedione and DHT and pituitary oxytocin becomes too low (as a result of the exhausted pituitary-adrenal and testicular axis) to suppress prostaglandin E2 (an inflammatory hormone) release. Other excessive stress hormones prolactin, cortisol, noepinephrine and epinephrine can also induce excessive prostaglandin E-2 release (and not only) from tissues. Excessive prostaglandin E2 in the bloodstream causes not only inflammation, but also weak neuro-immunity.
Excessive inflammatory and excitatory epinephrine or/and cortisol, prostaglandin E-2, medication or street drugs, blood sugar, prolactin, estrogen, alcohol, cigarette chemicals, along with deficiency of insulin, oxygen, androgen hormones (hGH, DHEA, testosterone, DHT and oxytocin) and electrolytes will thin and harden (reduce the elasticity and expansibility) the tunica albuginea and its sheathing spongy corpus cavernosa for erectile dysfunction, penile shrinkage and collagen scarring.
A mechanical penile damage will induce hardening and collagen scaring of the erectile tissues (by the uncontrolled release of prostaglandin E-2) when one expands it up beyond the elasticity that the tunica albuginea can endure physically and biochemically. It's advisable to reconsider jelqing, stretching, hanging or pumping up your penis without sufficient preparation.
One has to boost prostaglandins E-1/E-3 and Nitric Oxide (cGMP) release from the adjacent healthy erectile tissues to soften the collagen scar or prevent collagen scar formation. It will also heal the damaged penile erectile, elastic tissues, nerves and blood vessels in tunica albuginea and its sheathing spongy corpus cavernosa.