Holy Basil leaves powder
Holy basil is used to treat many conditions, including H1N1 (swine) flu, diabetes, the common cold, headache, fever, stress, upset stomach, earache, and more. It has also been used as a mosquito repellant and topically (on the skin) to treat ringworm. 
Studies have shown that holy basil has a wide range of health-promoting properties including:1
Adaptogenic
Anti-arthritic
Anti-coagulant
Anti-diabetic
Anti-inflammatory
Anti-pyretic (prevents itching)
Antidiarrheal
Antimicrobial (including antibacterial, antiviral, antifungal, and more)
Antioxidant
Antitussive (treats cough)
Liver-, brain-. and heart-protective
What Are Adaptogens?
Holy basil is an adaptogenic herb. Adaptogens are substances found in plants that help boost the body’s resilience in dealing with stressors. Because the effects of stress on the body play such a huge role in the aging process, adaptogens are also considered to have anti-aging properties.
They may perform many different functions including:
Balancing hormones such as cortisol (the stress hormone)
Improving brain function
Boosting the immune system
Lowering inflammation
Improving energy levels
Improving organ and bodily system (such as GI) function
Holy basil is used for its many health benefits, and is used widely in Indian Ayurvedic medicine, but there is insufficient evidence for the treatment of many conditions, including:
Stress
Headache
Anxiety
Diarrhea
Fever
Nausea and indigestion
Back pain
Earache
Cold and flu
Dysentery
Genitourinary disorders (conditions involving the urinary system and genitals)
Bronchitis
Viral hepatitis
Malaria
Tuberculosis
Ringworm
Snakebite antidote
Diabetes
Asthma
Heart disease
Dosage
The safe and effective dose of any type of medication varies, depending on a person’s age, weight, health condition. and other factors. A safe long-term dose of holy basil (tulsi) has not been well established in medical research studies. But a range of dosages was used in short-term studies, these include:2
Early research discovered that taking 500 milligrams (mg) of holy basil leaf extract two times each day for 60 days resulted in reduced anxiety and depression.3
 A dose of 300 mg per day of holy basil leaf extract can be given (for 30 days) for central nervous system disorders.5
n preliminary studies, taking 400 mg of holy basil extract in the morning and 800 mg at night for six weeks decreased many symptoms associated with stress, these included:3
Sleep problems
Sexual problems
Severe fatigue
Memory problems
A dose of 10 grams of holy basil leaf aqueous extract can be given 1 to 4 times per day in equal doses As a tincture solution, the average dose is 30 drops per day in three equal doses. Holy basil whole-plant aqueous extract of 6 to 14 grams is an average daily dose.