Sustanon is an injectable testosterone injection used in adults to treat hypogonadism. It’s injected intramuscularly, typically in the buttocks, upper leg, or upper arm. Sustanon combines four active ingredients - testosterone propionate, phenylpropionate, isocaproate, and decanoate - for best effects. Dosages depend on prescription, but typically 1mL is injected every 1-4 weeks. Medication should be stored at room temperature and properly disposed of. Sustanon is FDA-approved for men with medical conditions of hypogonadism