I don't think the two are comparable. Losing virginity is experience that can't be taken back, the same as using steroids, but the effect on a physique of one small cycle can become negligible over time.
I think it should be classified as clean. not natural.
Cause once you enter the gray area, you can argue all day. Is one cycle, then ten years off, considered natural? What about 2 cycles, then 8 years off? Soon you'll have lifetime juicers that have taken 6 months off claiming "I'm all natural, you juicer pricks!"