This site's own realistic-timeline table lists this specific second period — worth understanding it on its own, distinct from the habit-building period before it.
This site is direct: some users report smoother morning breathing and less end-of-day chest heaviness during weeks 3-4, while reliable, dramatic changes this early are explicitly named as not realistic.
John M.'s featured quote specifically describes smoother breathing, especially in the mornings, after a few weeks — worth reading his individual account as consistent with this stated second-period timeline.
Backed by a 60-day money-back guarantee.
See The Current BreathiZen Offer