There are possible estrogenic side effects of Nandrolone despite it not being a very estrogenic hormone, at least not directly. Nandrolone does aromatize slightly. Aromatization refers to the conversion of testosterone to estrogen . This takes place when the testosterone hormone interacts with the aromatase enzyme. When the conversion takes place this can cause estrogen levels to go up, which can promote gynecomastia and water retention. High blood pressure can also become an issue if water retention becomes severe. Along with the low level of aromatase activity Nandrolone is also a progestin and has a strong binding affinity for the progesterone receptor. This may stimulate the mammary tissue and enhance the risk of gynecomastia in sensitive individuals.
Combating the estrogenic side effects of Nandrolone can be achieved by the use of anti-estrogen medications, specifically Aromatase Inhibitors (AI’s) such as Anastrozole ( Arimidex ). Selective Estrogen Receptor Modulators (SERM’s) are also sometimes used, such as Tamoxifen ( Nolvadex ). However, AI’s are the proper choice as they will directly reduce serum estrogen levels and SERM’s will not. An AI should be enough to reduce and avoid gynecomastia unless the individual already has existing gynecomastia that could potentially be exasperated.
Important Note: It’s often been said that Nandrolone based gynecomastia is based on increases in prolactin. It is true that 19-nor steroids can increase prolactin, which can also negatively affect libido and erection function. Some men may need to use a dopamine agonist to combat this. However, it is not prolactin that causes 19-nor based gynecomastia but rather the imbalance between estrogen and progesterone. If you merely combat prolactin you may find yourself with the very gynecomastia you tried to avoid.
For bodybuilding beginners dosages of 200mg per week are usual. This is distributed in the first two weeks to 2 injections of 100mg every days. An injection of 200mg per week is then usual.
For advanced bodybuilders dosages of 200 – 600mg per week are usual.
Dosages of 1000 – 1600 mg per week can be found in the professional area. In the dosage range of more than 600mg / week you should consider increasing the dosage of other steroids since the side effects increase with Nandrolone Decanoat at doses over 600mg per week disproportionately.
Decanoic acid acts as a non-competitive AMPA receptor antagonist at therapeutically relevant concentrations, in a voltage- and subunit-dependent manner, and this is sufficient to explain its antiseizure effects.  This direct inhibition of excitatory neurotransmission by decanoic acid in the brain contributes to the anticonvulsant effect of the MCT ketogenic diet .  Decanoic acid and the AMPA receptor antagonist drug perampanel act at separate sites on the AMPA receptor, and so it is possible that they have a cooperative effect at the AMPA receptor, suggesting that perampanel and the ketogenic diet could be synergistic.