Tulsi Basil/Holy basil - ocimum sanctum

If you love the scent of clove and cinnamon, you'll love the aroma of Tulsi Basil!  Even better are the benefits of this dynamic essential oil.  Let's review Tulsi Basil's therapeutic properties and its safety considerations.

The two major chemical constituents in this oil are Eugenol (a phenol) at about 50 - 55% and Beta-caryophyllene (a sesquiterpene) at about 30 - 35%.  

The combination of these chemicals makes Tulsi Basil strongly antimicrobial.  β-Caryophyllene is a cannabinoid that works with our immune system and is antibacterial, antiviral, and antibiofilm.  Eugenol is antibacterial, antifungal, and antiviral.  Diffusing a blend with Tulsi Basil during a cold or flu may help  speed up recovery.  It has applications for Athlete's Foot, helping control plaque, and MRSA.

Both chemicals are anti-inflammatory, antispasmodic, and analgesic.
β-Caryophyllene also has a local anesthetic effect.  Sufficiently diluted in a topical blend, Tulsi can help reduce local swelling, muscle spasms, and pain. This makes it a good choice in blends for acute injury and arthritis flare-ups. These properties also make it carminative - it'll help reduce gas, bloating, and cramping.

These two constituents are also antioxidant.  In studies, they are showing promise in preventing and/or slowing the progression of certain cancer cell lines.  

Safety:  Phenols are chemicals that are very harsh on the skin.  Tulsi Basil's high phenolic composition in the form of Eugenol makes it an oil to be used at low dilutions and for short periods of time.  This oil may inhibit blood clotting.
Robert Tisserand recommends a maximum dilution of 1% (5 - 6 drops per oz of carrier oil).
Drug interactions include Pethidine, SSRIs, MAOIs, and anticoagulants
Do not use if you have a blood-clotting disorder, peptic ulcer, or for 1 week before to 2 weeks after major surgery.
Do not use if you are pregnant or breastfeeding.
Based on the high level of Eugenol, I recommend that any blends you make which include Tulsi Basil should also contain carrier and essential oils that are skin-healing, and I recommend using such a blend for a maximum of 3 days in order to minimize skin-damaging effects.