Much will depend upon the nature of the world you inhabit. The way things work, you see. Your question happens to have crossed over the Wonchaunce Barrier and into a world where (most) people don't know much at all about dragons, to say nothing of the poor sod who's a weredrake and is trying (or perhaps whose parents wanted him) to pass for entirely human in nature.
Now, in The World, there are dragons of various sorts. Most are relatively small (like this dragonet) and very few kindreds that I'm aware of sport scales such as you're familiar with. Like this little fellow, most dragons sport feathers in a wide array of shapes, colours, hues and lengths. Your average dragon in The World is a veritable Mardi Gras float all unto himself.
There are also various conditions (some entirely mundane others more thaumic in nature) that may require some kind of dwimcrafty potion to cure or at least mitigate symptoms. I am not aware of any kind of human-dragon hybridisation occurring in Gea, but there are other similar hybrids in existence. Skinchangers, for example, are one sort. These folks have an extrinsic magical ability to change the form & appearance of their bodies. Werepigs and Werehounds, for example, are another sort. These folks have an inborn, geno-phenotypical expression of two different sorts of beings. Much like a wild chimera, these folks express within their physical beings aspects of both sides of their heritage. Werehounds, for example, pass relatively easily for Men, but they have doggy ears and a slightly pronounced & doggy face. Their smiles, when they smile at all, confirms the suspicion. Werepigs are a very low-brow kind of person, more beast than intelligent creature. Their overall form is like a very burly Man, but their snouts, tusks and bristles give away their boarish heritage.
Now, in Gea, it is possible to obtain, generally at great expence (both in hard money and also in side effects suffered), certain medicinal potions that can dampen or even eradicate an extrinsic characteristic. Generally speaking, it is not possible at all to eradicate the hybridism of the latter. And the reason is quite simple: the one is an ability, while it arises from the curious alchemy of mind, magic and genes, it is a variable and alterable characteristic of a person. It can be improved or repressed by external helps --- practice makes perfect, but this potion makes moot! The latter is the physical expression of the genetic code of an individual. And while Lamarck has a greater say than Darwin in many matters, even ordinary magic can not alter how many limbs and fingers and hearts a person is supposed to have. So it would be if you were born in Gea. A potion might suppress secondary characteristics, such as the growth of flamboyant red and blue feathers down your spine, no potion could alter the basic form and substance of a weredrake.
Generally speaking, once you stop drinking such a potion, it ceases to be effectual. Whatever it was designed to prevent from sprouting will begin sprouting, because that's what your genes are telling your body to sprout. It may be slightly uncomfortable at first to find long feathers growing from your crest and spine, or wings growing from your scapulas, but you'll soon get used to it! Just remember, in many jurisdictions around the polyverse, your gently used but no longer needed shirts will be a tidy and tax deductible charitable donation!
As for natural philosophical studies into the matter in general, you might consider Limberjack & Wonstable's foundational research into the Alterable & Inalterable Characteriſtics of the Werebeast with Particular Attention to Thoſe Changes of Early Development (Univ. of Auntimoany, 1944). Also, there is an earlier anecdotal work by Ybricg-Silverorn, that is, Life of the Halfborn: Tales of Well Known Werefolk (Wootman & Sellars, 1794).