I wouldn’t recommend this combination based on that reasoning alone. Raising testosterone and growth hormone doesn’t automatically make a stack effective or safe. Also, “one injection” describes frequency, not the actual Sustanon dose.
Sustanon contains testosterone esters and can increase blood pressure and hematocrit while suppressing sperm production. Its medical use requires an appropriate diagnosis and monitoring. 5373
MK-677, or ibutamoren, stimulates growth hormone release; it isn’t growth hormone itself or a SARM. In a clinical trial involving older adults, it increased growth hormone and fat-free mass without improving strength or function. Blood glucose increased and insulin sensitivity declined. Those findings don’t establish benefits for this combination in healthy lifters. PubMed
MK-677 is not FDA-approved. The FDA highlights risks including increased appetite, fluid retention, altered glucose metabolism and potential heart failure in certain individuals. The proposed 25 mg daily amount should not be treated as an established safe bodybuilding dose. FDA
Before proceeding, discuss the exact products, doses, health history and goals with a qualified clinician. If Sustanon is prescribed, speak with your prescriber before adding MK-677.