For most SARMs, PCT is necessary after the cycle is complete.
Because SARMs are so potent, they tend to overwhelm the body’s hormone system, replacing the hormones the body produces with those that are created by it. The problem is that this is a temporary change in leadership: SARMs are only going to be there for two or three months.
What happens after that?
SARMs suppress testosterone, so you take post-cycle therapy. PCT will help you get your hormone levels back to something resembling normal and allow you to escape testosterone suppression.
Not taking PCT can lead to a whole load of downsides, including impotence, gynecomastia (growing breast tissue) and various other hormonal effects. PCT helps get everything back on track, and that way, you can continue bodybuilding for years and years to come.