I have seen a few formulas outside of AM that are intended to be used indefinitely. None of which have entirely impressed me much but that is just because they have all sabotaged the formula in one way or another. The ingredients needed are somewhat different than the typical test boosters and are more centered around male reproductive organ health. Healthy testicles can produce more test!
A few of the ingredients in Testruction fall into this category, as well as the Gentiana species, Cistanche, Raw Orchic, and there are many more. People often turn their nose up at Trubulus but it is actually really good for you and is great for increasing blood flow to the genitals. Sore common ingredients that also don't particularly have to be cycled are Tongat Ali, Mucuna, Ashwaganda, and let's not forget our ZMA, vitamin D, and K2, ALCAR, and Boron. A couple of mild AI's thrown in the like Naringin, Hesperidin, Tumeric, low dose Damiana with high yield Acacetin.
Ever wonder why people don't seem to report getting much out of Testruction? It is because most of that formula will show the greatest benefits when used for a longer time frame than your typical test-booster.
There is so much untapped potential out there waiting to be compiled into the ultimate long term, no cycling required testosterone support formula if only there was someone with the knowledge and motivation to produce it!