That’s going to depend on which estrogen testing you use, there is the Liquid Chromatography–Mass Spectrometry (aka LC/MS/MS method) <35 and the Roche ECLIA methodology.
You will find healthy young men with estrogen <35 and obese men 35>. In fact DR. Saya has published papers on men with natural testosterone and estrogen 35> and are showing signs of partial HPTA suppression.
You should be concerned with whether or not you have symptoms related to high estrogen, high estrogen can turn man into a emotional bitch, brain fog, fatigue, low libido, problems maintaining erections and water retention.
I often hear men say who have high estrogen that they don’t feel any benefits from TRT.