Variously called Death Day, Decision day, and a number of other less kind words, D-Day was the day that the Allies began the big push from the coast of France all the way to the heart of Germany, ending WWII.
More importantly when it comes to cystic acne, tea tree oil can be harmful to your skin when applied in high concentrations. Some individuals have reported severe skin irritation and allergic dermatitis after applying too much tea tree oil, or applying the proper dose too frequently.
Tea tree oil is an essential oil obtained by steam distillation of the leaves of Melaleuca alternifolia, a plant native to Australia. Historically, the leaves were used as a substitute for tea, which is how tea tree oil got its name. The part used medicinally is the oil from the leaves. So far, research on the use of tea tree oil is limited. If you're considering using tea tree oil, talk to your doctor first. Keep in mind that tea tree oil should not be used as a substitute for standard care in the treatment of any health condition.