I've noticed an improvement in my hair after taking zinc, but it still isnt 100%. Is hair regrowth slow and gradual?

Shedding rate is now extremely low. My hair is definitely thicker after comparing photos but its still not quite back to baseline, yet. Its been about 3 months since I started taking zinc, and I've noticed every 2 weeks or so my hair improves. It appears like my hair seems to improve ever so slightly each week or so, but its an extremely gradual process so far. Is this normal of hair regrowth? Is it reasonable to expect more rgrowth through the rest of the year? There is a definite change.