Never Applied Oil. Can Cantharidine Hair Oil Have Any Side Effects?

Hi! I am a girl of age 20. I have less hairs on central crown of my scalp. I lost them years back and since then, I haven t got that pre-hairfall thickness again. I have never applied oil in my hairs since my teens(not even monthly!) Someone told me to apply castor oil in my hairs but I didn t get it in my locality so I bought cantharidine hair oil. Its ingredients are- Arachis oil- 12.5% v/v, light liquid parafifin 86.0% v/v & cantharidin. The bottle says- For preservation and growth of hair. I have never heard about this hair oil so please tell me, Can this oil have any side effects? And Can I apply it like the regular oils or is it to be applied for a certain duration?? Presently, I have no dandruff, no hairfall but I have some grey hairs. The only problem for which I want to use this oil is less hairs on my central crown. I have normal hair thickness elsewhere, including my hairline. Thanks