Out of all the common compounds, testosterone, trestolone, nandrolone, and Dianabol aromatize. You are almost guaranteed to need an AI when using sufficient doses of these steroids or any of their prohormones. However, just because a compound does not aromatize does not mean that an AI will not be necessary. For example, a rise in estradiol can occur via a reduction in SHBG, which is an effect of many steroids, as well as SARMs.
Thus, before beginning a cycle of any suppressive compound, an AI should be acquired.