Test "Boosters" that are truly natural like nettle root and ZMA - no need to cycle (unless someone knows something I don't - entirely possible) - they just free up test through natural means.
The test boosters that are anti-e's - you need to cycle those because they will crush your sex drive and free test and estrogen. You need estrogen - not good to smash it down for long periods of time. In fact I don't think it's good to boost your test by decreasing estrogen in an effort to gain muscle. Maybe to cut up a little I guess. But they suck overall.