Testosterone suspension is one of the top choices of bodybuilders and athletes when it comes to steroids. This is because this steroid provides the fastest and best results when it comes to weight gain and is one of the most effective steroids for weight gain. Testosterone Suspension is an injectable formulation containing a water-based unesterified testosterone. Among athletes, testosterone suspensions are known for being extremely strong injections, often ranking among the highest in testosterone. Very fast-acting testosterone suspensions only maintain elevated testosterone levels for 2-3 days.