Sources in the Union information and broadcasting ministry said the letters will be sent out following a nudge from the Union ministry of Ayurveda, Yoga and Naturopathy, Unani, Siddha and Homeopathy.
The Ayush ministry, a few months back, had made some changes in the Drugs and Cosmetic Rules to make it illegal for traditional medicine manufacturers to advertise cures or treatments for over 35 medical disorders, such as baldness, infertility and short height.
Under the new rules, manufacturers of Ayurvedic, Unani and Sidhdha drugs cannot advertise cures, diagnosis, treatment or prevention for cancer, diabetes, high blood pressure, skin darkness, short height, baldness and greying of hair, dark skin, sexual performance and cataract, among others.
"We have been getting complaints that there are atrocious claims by manufacturers of traditional drugs that are particularly publicised thorough outdoor advertisements in smaller cities ," said a director in the I&B ministry.
"Most of these advertisements are placed on the walls of houses along railway tracks and highways to grab eyeballs of commuters and are highly exaggerated," the official added. "Since we do not have the mechanism or resources to get such advertisements withdrawn, we are advising the state governments to alert the district administrations to put curbs on these kind of practices."
The development comes after earlier bids to control such advertisements have failed, another senior official said.
In August 2014, the information and broadcasting ministry had issued an "advisory" to TV channels asking them not to carry "dubious teleshopping advertisements that claimed "magical" cures for cosmetic and health problems, offering viewers "immediate weight loss" and "divine" benefits.
The move, however, did not have much of an impact and such ads continue to be shown on general entertainment, cinema and news channels, mostly in the afternoons and between 11pm and 2am.
Ministry sources said an inter-ministerial committee, formed to look into complaints against such ads, had suggested that a more effective way of curbing the ads would be by bringing a law to bind manufacturers, rather than broadcasters.
"The matter was referred to the Ayush ministry as a comprehensive law was required," an official in the broadcasting division of the ministry said.
He also added the new rules by the Ayush ministry had been introduced in view of a large number of complaints received against such products.
The official pointed out that the Drug and Magic Remedies (objectionable advertisement) Act, 1954, which controls advertisement of drugs in India, does not cover traditional medicine.
"The claims made by most of the manufactures of these products are too good to be true and sound almost unbelievable, but there were no laws to directly deal with them so the new changes are significant," he said.
Interestingly the new norms have been put in place even as several senior functionaries of the central government, including the Ayush minister Shripad Naik, had been trying to project traditional medicine as being capable of treating even incurable or intractable diseases.
Only in March this year, for instance, Naik had claimed that a Yoga-based cure for diseases such as diabetes and cancer was on its way, and a Bangalore-based institute would provide "proof" of this within a year.
Executives in the Advertising Standard Council of India - the watchdog for the ad industry in the country - said introducing new rules and penalties to govern the publicity for alternative medicines was aimed at dealing with violators in a more "efficient manner."
"The council does issue notices to manufacturers whenever we notice misleading ads, but a regulation in place for this category of products is of immense help," said a functionary of the council.
"Most such ads are, however, outdoor in nature and hence can be rightly tackled by the district administrative authorities. It is good that the government has paid attention to the issue."