How long do miniaturized hairs grow? Do they have the same growth time as terminal hairs?

This can vary. I suggest seeing a hair loss expert now to evaluate and go over your condition and provide you information about your best treatment options and supplements. There are great non-invasive options like prp/progesterone and/or hair transplantation. See an expert. Best, Dr. Emer

In the early stages of androgenetic alopecia (first few years), miniaturized hairs grow almost the same length as original hairs (not quite but close). As time passes, and if androgenetic alopecia progresses, them miniaturized hairs grow in the scalp for shorter and shorter periods. In advanced cases, hairs affected by androgenetic alopecia grow for only a 2-3 months - and are very, very short and very, very thin. We call these "vellus-like" hairs rather than miniaturized hairs but they are a type of miniaturized hair.  Over time, vellus like hairs just don't grow any more.

Early in the process, they grow just like normal hair that is not miniaturized. Miniaturized hairs will frequently hang in a long time, especially when they are at the end of their life. By hanging in I am not suggesting that at the end of their life that they are still growing, they just don't fall out on occasion