How low does a testosterone level for a 22 year old need to be for an endocrinologist to feel comfortable prescribing testosterone?

Depends on diagnosis: Androgen deficiency such from pituitary failure would need replacement therapy. So foremost finding the diagnosis or the cause for low testosterone by the endocrinologist must be answered than the level.

Need it?: Consider your overall functionality after assessing your history, physical exam on testes and other body parts, and possible repeating testosterone test at proper timing. The number alone should be not be the only deciding factor to use testosterone. Please discuss with your doctor in the special field.