Nandrolone undecanoate is an injectable form of the anabolic steroid nandrolone,like the shorter acting Nandrolone Decanoate (Deca-Durabolin), has been used to produce steady and significant gains in strength and ‘high quality’ mass (lean mass that is more likely to remain post-drug-use). This drug’s base ingredient is the anabolic steroid nandrolone. The ester applied here is one carbon atom longer than decanoate, and consequently forms a very slightly longer-lasting drug deposit at the site of injection.Nandrolone undecylate is an effective compound that produces quality, long-lasting muscle gains. This is because of the relatively long half-life of the drug (around 18 days). Even without a further protractedtherapeutic window, nandrolone undecanoate can be comfortably injected once every 1 to 2 weeks, which reflects its slow-acting nature. It was once highly favored by athletes and bodybuilders for its ability to promote slow steady gains in lean mass with minimal estrogenic or androgenic side effects.