I do not consider trenbolone to be capable of causing or aggravating gynecomastia. I do not know of a single case where the source of trenbolone was Parabolan (back when it was available), Finaplix H, or Component T-H. The problem appears to occur only when the source is an underground lab or the home preparation is made from powder from a black-market supplier. Since trenbolone’s wholesale price direct from a manufacturer is much higher than that of most anabolic steroids , it shouldn’t be surprising that substitution or partial substitutiion would often occur with underground products. Additionally, it might be that some have mistakenly made preparations from Finaplix S, which definitely would be capable of causing gyno, as that product includes estradiol benzoate as an ingredient.
Sorry ladies, but Trenbolone is not recommended for you to use. Trenbolone is known for having virilization effects. It will lead to many things that happen with masculinization, including a deepening of the voice and hair growth. Hair growth can occur both on the body as well as on the face. Clitoral enlargement can also occur. It will also bind itself to progesterone receptors in the body, leading to the body increasing its prolactin levels. Lactation and breast growth can occur as a result at smaller amounts than the other side effects listed above. If you are serious about using Trenbolone and you want to reduce some of the side effects, then things like bromocriptine and Vitamin B6 can be used.
Trenbolone acetate is a modified form of nandrolone.  The structure of trenbolone acetate is a 19-nor classification, which represents a structural change of the testosterone hormone. Trenbolone acetate lacks a carbon atom at the 19 position and carries a double bond at carbons 9 and 11. The position of these carbons slows its metabolism, which greatly increases its binding affinity to the AR, and inhibits it from undergoing aromatization into the corresponding estrogenic metabolite. Trenbolone acetate contains trenbolone modified with the addition of a carboxylic acid ester ( acetic acid ) at the 17β-hydroxyl group.  This facilitates the slow release of the AAS from the area of injection.