It is said that the Tulsi is a purifier—that purifies not only the soil where it grows and the air around it, but also our mind, body and soul. The Holy Basil sanctifies the home where it grows; and the air and soil around it is free from worms, insects, snakes and disease-producing bacteria and organisms. One of the varieties is also used in cooking and as a flavouring herb (Basil) in Italian and other cuisines.

The Holy Tulsi cures the body of all kinds of ailments as it cleanses the intestines of all toxic matter and infections. Its flowers are germicidal and its leaves even more so, due to the potent volatile oils and high organic mercury-like compound that they contain.
One of its contents (like Thymol) clears skin disorders. Basil leaves & seeds are used extensively to treat digestive and respiratory disorders, as also problems of the circulatory, excretory, urinary, nervous and reproductive systems.
Precautions:                                                                                       
1.      It is advised not to chew the fresh leaves of Tulsi too much, (probably due to its high organic mercury-like content which may affect the teeth), but they can be broken into bits or crushed and swallowed without much chewing.
2.      Being potent in its action, for general good health, 2-4 fresh leaves or ¼ tsp. of the dried powder, is usually enough for the day. The fresh leaves are more potent than the dried powder as they contain volatile oils that evaporate on drying the leaves.
3.      Never take milk with, or soon after Basil. If herbal tea is made with Tulsi, have it with honey and/ or ginger/ lemon juice, but always without milk.

4.      ‘Shyama or black Tulsi’ is far more potent for medicinal purposes than ordinary Tulsi.
Uses:
1.      For colds and cough: ----a) Juice of Basil leaves or its powder taken with honey helps cure acute colds, coughs and sore throats.
b) Herbal tea of Tulsi, black pepper and ginger with honey and/or with fresh lemon juice or Amla for its Vit.C, (but without milk) relieves colds, coughs, sore throats etc. very quickly.       
2.      For ear-aches: A drop or two of warm Tulsi juice in the ear cures acute ear-aches.
3.      For migraines: Take two gms of the powder and mix with ½ tsp of honey. Lick the paste once or twice at an hour’s interval. Usually, not more than two doses will be required to cure the migraine.
4.      One to two gms of Tulsi seeds taken with water for a few days purifies the blood, and improves and thickens semen.
5.      For hair: Put 21 leaves of Tulsi (or 1 tsp. of dry powder) and 10gms of Amla powder in a bowl. Add enough water to make a paste of it. Apply it on the scalp and head and let it dry. Wash off thoroughly with cold water. Prevents hair loss and cures dandruff.

6.      For weak limbs and paralysis: Boil a few Basil leaves (preferably ‘Black Tulsi’) in a glass of water, and let them infuse in the hot water for some time. When cool, strain and massage this water on affected limbs/parts. Also take 1/4th tsp of the powder internally, daily. With continued use, it strengthens & improves paralyzed limbs.
7.      For general good health & prevention of infections and many common illnesses, take a quarter teaspoon of Tulsi powder or paste with honey or water every morning, or use it in a herbal tea with ginger, lemon grass, amla, mint, or other herbs. 
8.      It is said that 4 peppercorns (coarsely crushed), and 2 leaves each of Neem and Tulsi (bruised and broken) and soaked overnight in a little water (1/4th – ½ cup) and drunk first thing in the morning on an empty stomach, will never allow the occurrence of Malaria, intermittent fevers, infections, skin and respiratory problems, allergies and other diseases.