Nasyam is one of the Panchkarma Treatment, which is used to insert the medication in the nostrils. 

Administration of drugs by the route of nasal cavity is termed as Nasya, Nāvana, Nasya karma.

Nasya is one among the important modes of drug administration. The medicine in any of the form like swarasa, kwatha, ksheerapaka, churna, dhooma, aushadh siddha taila etc is administered through nasal route. The other names for Nasyam are Siro-virechana, murdha-virechana, sirovireka, nasta pracchardana, nasta karma and nasya.

नस्तः कमाच कुवीत शिरोरोगेषुिास्त्रशवत्।

िारं शह शिरसो नासा तेन तद्व्याप्य हशन्त तान्॥

Maharisihi Charaka Says that nasya karma is done in all diseases of head and says that nasal route is main way to treat these diseases.

ऊध्वाजिुशवकारेषुशविेषान्न्स्यशमष्यते।

नासा शह शिरसो िारं तेन तद्व्याप्य हशन्त तान्॥ 

Acharya Vagbhatta says that nasya chikitsa is the special treatment in urdhvajatrugata vikara (diseases of head and neck).

औषधम औषधशसद्धो वा स्नेहो नशसकाभयां दीयतेइशत नस्यं । 

Maharishi Sushruta says that the aushadha or aushadha-siddha sneha if administered through the nasal route it is called nasya.