Lavender oil and tea tree oil to remove facial hair Add 1 tbsp of lavender oil to 4-6 drops of tea tree oil. Use cotton ball to apply this lotion over face. The study was carried on a group of women affected with mild hirsutism. 12 members of one group (A) are treated with lavender and tea tree oil spray. The second group of 12 women (B) was given placebo twice per day for 3 months. After 3 months hormone evaluation and hair growth measuring were taken.