Natesto nasal gel is an example of testosterone microdosing. It causes some but not complete suppression and the achieved average daily total testosterone level is not very high. However, it uses pure testosterone base not esters, and doses 3 times daily.I can attest to this. Last year I tried microdosing cypionate EOD out of curiosity. It suppressed my natural production and I ended up feeling worse than my pre-TRT baseline.
Since the natural testosterone production is 6mg/day, I estimate that the testosterone absorbed from Natesto is 2 mg OR LESS at each dosing. It should be possible to imitate that by injecting testosterone base 3 times a day.