Testop (Testosterone Propionate) is an injectable form of the primary male androgen testosterone. The added propionate ester slows the rate in which testosterone is released from the injection site. Still, Testosterone Propionate is much faster-acting than other testosterone esters and therefore requires a much frequent dosing schedule.

Estrogenic Side Effects

Testop (Testosterone Propionate) is readily aromatized in the body to estradiol (estrogen). The aromatase (estrogen synthetase) enzyme is responsible for this metabolism of testosterone. Elevated estrogen levels can cause side effects such as increased water retention, body fat gain, and gynecomastia.

Testop (Testosterone Propionate) is considered a moderately estrogenic steroid. An anti-estrogen may be necessary to prevent estrogenic side effects. One may alternately use an aromatase inhibitor which more efficiently controls estrogen by preventing its synthesis.

Estrogenic side effects will occur in a dose-dependant manner, with higher doses (above normal therapeutic levels) more likely to require the concurrent use of an anti-estrogen or aromatase inhibitor.

Androgenic Side Effects

Testosterone is the primary male androgen, responsible for maintaining secondary male sexual characteristics. Elevated levels of testosterone are likely to produce androgenic side effects including oily skin, acne, and body/facial hair growth.

Anabolic/androgenic steroids may also aggravate male pattern hair loss.

Women are warned of the potential virilizing effects of anabolic/androgenic steroids, especially with a strong androgen such as testosterone. These may include deepening of the voice, menstrual irregularities, changes in skin texture, facial hair growth, and clitoral enlargement.