the first noticable change - often within the first few days - is in the eyes, with a temporary deterioration in your vision for a few days, as the pupils change to a vertically-slit shape. It's not uncommon for eye colors to change either, perhaps turning orange or gold, or picking up bright, shining flecks of color within the iris.
At about three months in is when horn growth starts in earnest, and when the first patches of scales typically come in. This is also where the back pain starts, as the first stages of wing development begin. Here's a tip: back massages help a lot. By now most folks have a slightly awkward short tail.
By six months, scales usually cover half the body, tiny adorable useless baby wings have sprouted, the tail has reached sizes comparable to humanoid canids, and snout development is in full swing. By now it's usually apparent what kind of dragon you are - dragons come in a lot of varieties, and the transformation seems to vary greatly by individual. Horn sizes at this point vary a lot because of the sheer variety of dragon horn shapes and forms.
By a year in any traces of previous humanity such as exposed, scale-less skin, are typically gone. It normally takes up to another six months for the wings to finish developing to the point of allowing for flight and for one's draconic magic to fully manifest. Horns and tails have typically reached their full sizes by now.
Around a year and six months to two years in, the shapeshifting abilities inherent to much of dragonkind begin to develop. Most shift for the first time in their sleep - often crushing fragile beds under their full sized draconic forms. By this point, one is fully and irreversibly a dragon, and it's safe to stop the treatment. It's become a bit of a tradition in formerly-human dragon communities to celebrate ones first shifting with gifts and parties.
